why my gov surged and I couldnt win 1st place
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Category: Allis Chalmers
Forum Name: Farm Equipment
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=19483
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Topic: why my gov surged and I couldnt win 1st place
Posted By: mlpankey
Subject: why my gov surged and I couldnt win 1st place
Date Posted: 15 Oct 2010 at 5:28pm
<a href=" http://s738.photobucket.com/albums/xx26/pankeyc/?action=view¤t=securedownload.jpg - http://s738.photobucket.com/albums/xx26/pankeyc/?action=view¤t=securedownload.jpg "><img src=" http://i738.photobucket.com/albums/xx26/pankeyc/securedownload.jpg - http://i738.photobucket.com/albums/xx26/pankeyc/securedownload.jpg " border="0" alt="Photobucket"></a>The other 3 rod caps had to be loosend also to get the crank to turn . Rod bearings look good must have bent the other rods slightly also <a href=" http://s738.photobucket.com/albums/xx26/pankeyc/?action=view¤t=securedownload.jpg - http://s738.photobucket.com/albums/xx26/pankeyc/?action=view¤t=securedownload.jpg "><img src=" http://i738.photobucket.com/albums/xx26/pankeyc/securedownload.jpg - http://i738.photobucket.com/albums/xx26/pankeyc/securedownload.jpg " border="0" alt="Photobucket"></a>.  ------------- people if they don't already know it you can't tell them. quote yogi berra |
Replies:
Posted By: Dave(inMA)
Date Posted: 15 Oct 2010 at 5:47pm
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Ouch! ------------- WC, CA, D14, WD45 |
Posted By: mlpankey
Date Posted: 15 Oct 2010 at 6:02pm
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still amazed that it didnt do worse than fourth place ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gary in da UP
Date Posted: 15 Oct 2010 at 6:22pm
| I sure as hell wouldn't use that engine builder again. Spend a few bucks and hire one who pays attention to the details ?!! |
Posted By: Brian G. NY
Date Posted: 15 Oct 2010 at 6:25pm
| That was a low blow Gary!! LOL |
Posted By: mlpankey
Date Posted: 15 Oct 2010 at 6:27pm
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hahaha Your in luck Garry I don't build for anyone but me . A 25.00 rod 20.00 dollars labor to pull it out but the stuff it was hooked to priceless. A rod bent like that and still didn't have a worse finish than fourth place . King compression just imposed a tax On the good side it didnt break and the other three arent bent as bad. just weak rods sometimes you find the weak link when you run HOT. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: acd21man
Date Posted: 15 Oct 2010 at 6:32pm
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i see the problems IH weights lol ------------- 2 wd 45,2 D-17 diesel/gas 3 pt, 220,d21, 4020,2 4430s used daily http://www.youtube.com/channel/UCudh8Xz9_rZHhUC3YNozupw |
Posted By: mlpankey
Date Posted: 15 Oct 2010 at 6:43pm
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i wished it had ih gov weights i don't think they come apart as much as the ac gov weights do . I guarantee you if you polled the audience they would remember the ac over the rest. I am very competitive and can take a fourth place finish better when coming home with a broken tractor than I can coming home with a running tractor and a fourth place finish. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gary in da UP
Date Posted: 15 Oct 2010 at 7:04pm
| Back about 2004 the wd45 that I pulled had low oil pressure. My friend Bert helped me plasti gage the bearings. Two days before I pulled the drain plug and let her drip as we were vgonna check it out in frame. When we dropped the pan in looked as if someone had left shrapnel from a pakastani roadside bomb in there. It happens...... AC's have great governors until they fly apart. Anyway, needed some undersize rod inserts and cam bearings to fix. BTW, did you have fun pulling this year? You can't be pullin' for the money..... |
Posted By: mlpankey
Date Posted: 15 Oct 2010 at 7:17pm
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yes we had a stallion thought we had it figured out but s---- happens . we will check the crank to see if its bent and look at some aftermarket rods maybe titanium . I would like to see just how high she would turn then . I am doing away with the Allis gov. weights also. Until then we were needing a clutch to hold fourth gear and 18.4 /38 rubber to keep her hooked to the ground. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gary in da UP
Date Posted: 15 Oct 2010 at 7:23pm
| Hopefully your crank survived. But, are you having fun ??? |
Posted By: mlpankey
Date Posted: 15 Oct 2010 at 7:40pm
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I am glad that the rod bent and didn't break . The show lets the spectators to close to the track. If it had sent shrapnel flying it could have been ugly . I am not talking about the repair bill on the engine either. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Larry(OH)
Date Posted: 15 Oct 2010 at 8:22pm
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hows the cam holding up??? ------------- '40 WC puller,'50 WD puller,'50 M puller '65 770 Ollie *ALLIS EXPRESS contact* I can explain it to you, BUT I cannot understand it for you!! |
Posted By: mlpankey
Date Posted: 15 Oct 2010 at 8:41pm
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its good. moves alot of air ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gerald J.
Date Posted: 15 Oct 2010 at 9:17pm
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You need wider rods. In bending the direction it's bent the bending strength is proportional to the height cubed, but only the width. So a little bit taller I in the I beam gets strength rapidly without much added metal. Gerald J. |
Posted By: mlpankey
Date Posted: 16 Oct 2010 at 6:09am
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Gerald I believe in the laws of conservation of energy . I need a strong rod that dont take up alot of room and dont weigh a ton so the torque is not trying to push through the crank . ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: mlpankey
Date Posted: 16 Oct 2010 at 9:23am
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will 4340 chrome molly rod at $ 190 a piece work . Titaniums are 4 grand . hows the wieght on chrome can they be a little beafier than the buda rod and have more strength with less weight? never had a chrome rod just wondering ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gerald J.
Date Posted: 16 Oct 2010 at 10:14am
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Chrome moly steel is stronger than plain steel or cast iron. But I don't know what the original rods are either. My 19th edition Machinery's Handbook says rods are typically 1040 or 3141 steel. It doesn't show tensile strength or yield for those numbers. 1035 and 1045 are 83K to 96K tensile, 51K to 65K yield (1035), or 95K to 115K tensile and 62K to 80K yield for 1045. The range depends on the drawing temperature, probably on the heat treat too. 3140 is 103K to 175K tensile and 79-152K yield. I think of chrome moly as SAE 4340. This book says its tensile strength ranges from 120K to 210K and yield 95K to 190K. Yield strength is the load where the steel stops acting like a spring and takes on a permanent elongation from the stretch test. Tensile is where the elongation stops and it breaks. Comparing the best 4340 to the poorest 1035 the yield strength of the chrome moly rod could be 3 times higher for the same weight rod. The bending strength of an I cross section is proportional to the yield strength and proportional to the moment of inertia of that cross section. For a rectangular bar the moment of inertia is bxhxhxh/12. Height cubed. Its similar for an I cross section taking away the two bars of air. The important factor is h cubed means increasing the height without change anything else gets stronger in a hurry. If a rod was 3/4 x 3/8" bar stock its moment of inertia would be .013. If it was 7/8 x 3/8 bar stock it would be .021 an increase of almost 59% for a height increase of 17%. Since its the fibers at the outside flanges of the I that take most of the load, the strength of an I increases faster for the same change in height. A fundamental of a strength of materials course I took nearly 50 years ago. Gerald J. |
Posted By: DaveKamp
Date Posted: 16 Oct 2010 at 12:49pm
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Gerald's got it right on the spot, and if you look in Machinery's Handbook, or any other engineering reference on Materials, you'll find that subset of formulae under Section Modulus. An engineer many years my elder pointed out something that our college professors neglected to stress: Materials don't have strength- they have PROPERTIES. SHAPES have strength. The bending moment was obviously exceeded... going to a wider web, rather than a heavier rod, would've better resisted the bend. That's an awesome trophy, though... mount that on a nice piece of wood, engrave a tag identifying it... that's what I used to do with my boats' burned-out drive gears. |
Posted By: mlpankey
Date Posted: 16 Oct 2010 at 1:11pm
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I need a formula to equate how much energy is being exerted on the rod at a given rpm. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: wi50
Date Posted: 16 Oct 2010 at 3:15pm
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I'm sure it could be figured out but is dependent on many other things for a given RPM. Just a couple that come to mind quickly. It's going to depend on the rod angle, which is alwayse changeing, depending upon phasing of the crank. The force is also alwayse changeing throughout the power stroke as cylinder pressure drops and the rod angle changes. At 90* ATDC the rod is less likely to support the so called energy as the same energy applied when it is at 35* ATDC, but the force is different because of the change in cyl pressure, rod angle, piston speed, and a host of other factors. At different RPM's the cylinders will fill differtntly, the compression will be different as will the burn rate of fuel.
Piston speed, it's alwayse changeing and the less the rod angle (or the lesser rod ratio) the more dramatic the changes are, the more force on the rod for all other things equill. Piston side load, again the lesser rod angle, the less wasted energy. Are the piston pins or the bores themselves offset from the crank centerline? Again, going to change the angle.
I've got a nice trophy rod, bent completly over in a 180* and the top broke off. It wasn't the rod at fault. A valve broke in the keeper grove and dropped in wrecking a piston. Rod made it around and knocked the cam into many pieces. Pulled the oil pan off to find a valve, cam, lifters, piston and a pin in the bottom. I was just winding the engine up and at about 3000 RPM it make a cough and died, the plug in back of the cam went flying past and landed in the sled pan. The valve that broke had a dark spot 3/4 the way across the break, I don't think it was any good from the start. Even a good quality automotive valve can be bad. The rocker arm geometry was perfect and the valve spring pressure was nothing like in some automotive applications.
|
Posted By: BCPuller
Date Posted: 16 Oct 2010 at 4:32pm
| What kind of motor is this out of |
Posted By: mlpankey
Date Posted: 16 Oct 2010 at 5:10pm
------------- people if they don't already know it you can't tell them. quote yogi berra |
wi50 wrote:Posted By: Gerald J.
Date Posted: 16 Oct 2010 at 11:18pm
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Those rod stress details are probably in some text books on engine design, either for automotive or aircraft service. I do have such books in my library, but a big portion of my library is still in boxes and I don't know for sure where those books are. Gerald J. |
Posted By: Gerald J.
Date Posted: 17 Oct 2010 at 10:55am
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The real strength of materials problem here is buckling of a column and while bending stiffness is still the major factor, its much harder to compute what it takes to make it buckle. That's because part of the cause of buckling comes from the loads not being perfectly centered on the ends of the column but pin ends should take care of most of that centering. Its complicated by the sideways motion of the crank putting some bending forces on the rod and gets really bad when the crank shifts endwise when the thrust bearing gives up to bend the rods the flat way. That sideways bend is likely why you had to loosed two more rod caps to get the crankshaft to turn. You need tougher rods but watch out for rods that crack instead of bend. They tend to ventilate a crankcase in ways that make it instant junk. Gerald J. |
Posted By: DaveKamp
Date Posted: 17 Oct 2010 at 12:32pm
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I was thinkin' down the same lines as Gerald... specifically on the alignment issue. The 'energy' applied to the rod can be calculated at any specific angle, provide you have a whole pile of details, but the STRESSES applied aren't the same as 'energy'... it's the combined vectors of stress moments that caused the beam to yield. The picture is kinda fuzzy, and you don't have a second angle, but from what I see, the yield occurred on two different planes... as Gerald noted, I think the fact that you had to loosen other rod caps suggests that at the time of failure, there was enough deflection in the crank to cause the EXPECTED rod thrust to be augmented by some unexpected sideways thrust... like trying to walk with a rotated knee... hence, down it goes. And if that IS the case, there's really only two things I'd delve deeper into: 1) Is there some point in the crankshaft, where an incipient crack resides, that is allowing more deflection than the crank normally withstands (perhaps one that developed during the pull, and may be waiting to come unglued in the future?) or... Is there just not enough crank support from 3 main bearings to take this kind of punishment? One other thing to keep in mind (and I don't think it's the case but shouldn't be discounted), is that the rod's bending moment has equal opportunity to be exceeded both on compression AND power stroke... if there's a chance that your CR or timing advance was too far on THIS cylinder (or preignition), or the mixture was rich enough to hydraulically lock the piston slightly before TDC, the yield started, and was finished by the next stroke's event. Trophies are cool! (just kinda costly) |
Posted By: wi50
Date Posted: 17 Oct 2010 at 12:49pm
| my broken valve was an automotive replacment valve from a Chev. application, I do not rember the brand name, SBI comes to mind, but blame it on just plain bad luck. I guess it wasn't so "high quality" afterall. I just bought Ferrea valves to replace the set. |
Posted By: mlpankey
Date Posted: 17 Oct 2010 at 1:59pm
------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gerald J.
Date Posted: 17 Oct 2010 at 8:04pm
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To much load will bend a new rod if its not strong enough. I think you will find the bores of the two other rods no longer parallel that there's a bend in the rod in the thin direction that caused the bearings to bind on the crank. One way to get that bend would be for the crank to shift more than the crank shaft thrust bearing should have limitied it (typically .010 end play) That's why we are concerned about the crankshaft and the block. Gerald J. |
Posted By: mlpankey
Date Posted: 18 Oct 2010 at 6:17am
------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: DaveKamp
Date Posted: 18 Oct 2010 at 7:45am
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The crank might not be bent, but at the time the rod beam deflected, there was probably quite a bit of deflection... the crank is somewhat of a rubber band when loaded like that. Hydraulic locking isn't limited to coolant- since you're running methanol, a substantial amount of your incoming fuel comes in as droplets... and will tend to fall to the bottom of the chamber, and what doesn't burn (because the flame speed of methanol is slower than that of hydrocarbon fuels) you'll get a fair amount of unburned fuel pitched out the stack on full-roar. While passing TDC, the liquid component of fuel will be in that squish-band, driving your CR WAY up, and if there's enough fuel in there at the time, the amount of compressable (gasses) volume may not be quite enough to let that piston reach TDC. Diesels with leaky injectors can wind up in the same situation. |
Posted By: mlpankey
Date Posted: 18 Oct 2010 at 8:40am
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Dave ,are you certain on the flame speed ? ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gerald J.
Date Posted: 18 Oct 2010 at 10:57am
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Its possible the rods that were tight but don't appear bent are bent near the ends. That the rod bowed like ) but didn't reach yield in the middle of the bow, just at the ends by the journals and bent those. Its time to inspect those rods with flat plate, and pins to find the ends by the shop manuals for parallel journals and twist of rod. Usually done with a surface plate, those two pins and some precision measuring apparatus. Twist requires a matched pair of v blocks. I'm suspecting that Buda did the same thing to rods working out how heavy they should be, then made them heavier until their test engines didn't bend any in normal use. Then they added metal to just keep them from bending at normal power. You need tougher rods. Gerald J. |
Posted By: Brian Jasper co. Ia
Date Posted: 18 Oct 2010 at 11:44am
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Just curious here, if crank deflection is a problem, has Mitch reached the max power capability of the envelope? All this engineering talk is interesting. Anybody making super strong 226 cranks? ------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: mlpankey
Date Posted: 18 Oct 2010 at 12:16pm
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I agree Gerald I need stronger rods. Now my question is with a 780 gram piston how light should the rod be and have a high tensile yield . Still trying to stay in the law of coservation of energy being absorbed and transferred to the fly wheel as torque . Rather than being drove through the crank creating flex and other detrimental characteristics. You are also probably right on how Allis engineers determined if rods would endure . My hip pocket cant continue to endure . Hip pocket needs to feal the cost of what ever rod material and production cost it takes to endure only once. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gerald J.
Date Posted: 18 Oct 2010 at 2:28pm
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No matter how sturdy, all the drive parts, from the piston, the block, the rods, and the crankshaft have flex and springiness. Besides conservation of energy, the heavier the piston and the rod, the more weight to be balanced and if its a typical 4 cylinder tractor crankshaft without balance weights you don't have that balance, so you have inertia effects that are unavoidable and get worse with heavier parts. Without applying slide rule to formulae that I don't know involving column buckling and forces on the rod in the engine, my next rod would have half again the height and thickness to increase bending strengths by a factor of 3 compromising with thinner sections to cut the bending strengths in both planes back to about twice the Buda rods. Then I'd want to go to better steel, presuming the Buda rods are more ordinary than 4340, but I don't know that to be sure. They could have used great steel so changing the steel won't help. There should be experts in hot rodding rods that know how best to minimize bent rods and broken blocks while not impacting inertia and balance too much. Gerald J. |
Posted By: Gary in da UP
Date Posted: 18 Oct 2010 at 4:06pm
| Clutch is slippen' can't get traction, my guvn'r weights blew up, my connectin' rods are pretzl shaped. But I got compression, and a little bitty distributer that'll power 40 miles of bob wire fence. Why bother? Do you keep hitten yourself in the head with a hammer cuz' it feels so good when you stop? You seem to have some deep pockets thanks to your union job, or maybe you have some gubment grant money so you can explore the beaking point of innocent AC tractors and you provide some amusement, so to each his own. But you have never answered my ? Are you havin' fun? |
Posted By: mlpankey
Date Posted: 18 Oct 2010 at 4:34pm
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Any true blooded hotroder knows the answere .yes its fun . Its not as much monkey see monkey do as drag racing or dirt track. Yes making the ponies to tax the snott out of parts is cool. See the deal with the traction is the 15.5 /38 couldnt hold the power for three gears and the clutch couldnt hold the power for road gear and that was even with the rods shortening. So why do top fuel crews rebuild after every run so they can boast about having 8000 hp and driving through clutches right into 300 mile an hour. just hearing one of them makes me giddy . Spectators who were around the tractor friday night before the parts failed were giddy as well for you couldnt hardly move to the line for people comming up to it to feal the ground jar. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: mlpankey
Date Posted: 18 Oct 2010 at 4:41pm
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[QUOTE=Gerald J.]No matter how sturdy, all the drive parts, from the piston, the block, the rods, and the crankshaft have flex and springiness. Besides conservation of energy, the heavier the piston and the rod, the more weight to be balanced and if its a typical 4 cylinder tractor crankshaft without balance weights you don't have that balance, so you have inertia effects that are unavoidable and get worse with heavier parts. Without applying slide rule to formulae that I don't know involving column buckling and forces on the rod in the engine, my next rod would have half again the height and thickness to increase bending strengths by a factor of 3 compromising with thinner sections to cut the bending strengths in both planes back to about twice the Buda rods. Then I'd want to go to better steel, presuming the Buda rods are more ordinary than 4340, but I don't know that to be sure. They could have used great steel so changing the steel won't help. There should be experts in hot rodding rods that know how best to minimize bent rods and broken blocks while not impacting inertia and balance too much. Gerald We balanced the entire rotating assembly externally . You may be surprised then again you may not be surprised as to how bad a 226 stock engine is out of balance. ever notice how the hand clutch vibrates on them ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gerald J.
Date Posted: 18 Oct 2010 at 6:31pm
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Most slow speed 4 cylinder engines have no balance weights and so are out of balance all the time. Balancing externally takes care of the external world but works the crank shaft even harder. When you find the next step in sturdier rods, you will have to do that external balancing all over. Gerald J. |
Posted By: mlpankey
Date Posted: 18 Oct 2010 at 7:14pm
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yes every time you change a gram . even though it can be argued that in a in-line engine with piston motion strait up and down the two cylinders 1 and 4 and 2 and3 cancel each other. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gerald J.
Date Posted: 18 Oct 2010 at 7:51pm
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Except you still have that couple between the two cylinders going in opposite directions. And you wish that the couple from the front pair is opposed by the couple from the rear pair, but for higher speed, like my VW 2 L engine runs a fully balanced crankshaft for each cylinder runs smoothly up to at least 7000 rpm. Gerald J. |
Posted By: mlpankey
Date Posted: 18 Oct 2010 at 7:56pm
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we are on the same page. even though the automotive crank balancer that's in the machine shop i have the door key to just spins them a tic over 5g. PS crutch came through with the formula over on yts pulling forum . I had a few hecklers like Garry over there also. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Gerald J.
Date Posted: 18 Oct 2010 at 9:11pm
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A good sensitive balancer doesn't need speed, look at the modern tire balancing machines that balance a tire at less than 200 rpm. And you can't ever do a perfect balance job on a crank shaft because you have easily balanced parts like the crank journal and webs and the big end of the connection rod spinning in a circle coupled to the rod and the piston that don't spin in the circle but start and stop going in a linear path and the shank of the rod gets split between reciprocating and spinning parts. Then to add confusion to the coupling between the recipricating parts and the crank, the center of the crankshaft can be offset from the center of the cylinders to cut down on piston slap, to make the angle of the connecting rod less on the power stroke than the compression stroke. On top of that there's different forces on the piston each of the four strokes, probably smallest on intake (actually pulling against the piston, lifing the rod off the journal, riding on the rod cap), bigger on exhaust, a fair amount bigger on the compression stroke and then relatively huge on the power stroke. Gerald J. |
Posted By: mlpankey
Date Posted: 18 Oct 2010 at 9:25pm
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tire balancing machines. I remember working at the local full service gas station as a kid advancing up from pumping gas to tires then brakes to ac . I remember be excited at the purchase of the spin tire balancer . It would balance a tire at a rpm that would equate to 60 mile an hour when driving . gave you the weights needed on each side of the wheel in a digital read out . Its long gone and I still think the bubble balancer it replaced did as well if not better. oh well lets crunch some numbers . enjoyed it. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Ken(MI)
Date Posted: 19 Oct 2010 at 8:22am
| If you're going to push the envelope Mitch, you are going to break things doing it, plain and simple, engineering goes a long way, but engineering, coupled with testing goes further. Jet Engineering pioneered Titanium rods, rocker arms, valves, retainers and other race components almost thirty years ago, I was there, and made a lot of stuff that never even survived one dyno session. Hang in there, but if you don't want things to break, stay with the tried and true. By the way, 4340 is not considered chrome-moly steel, that title is reserved for the more garden variety 4130/4140 series that are easily weldable. 4340 get's the Boy-Dog status from the addition of 2% nickel, which is why it is designated a Cr-Ni-Mo steel, and has poor weldability amongst other significant differences, including the requirement of avoiding certain temperature ranges during heat treatmetn and tempering. You told me those Buda rods were forged at Atlas, which has me betting that they are nothing more that 1035 SBQ, if so, going to 4340 will give you two to three times the strength with proper heat treatment. Good luck |
Posted By: Hudsonator
Date Posted: 19 Oct 2010 at 6:43pm
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Here's a hint:
Give up some of that compression height on your piston pin location and get a rod that can offer you something beyond a 1.27 rod ratio. I'd have never wasted all that area and run a rod with anything less than a 1.57 ratio.
By the time you spend a ton of money on a rod beam that can stand such an angle, you'll be pushing pistons through your block sideways.
------------- There isn't much a WC can't do. WD's just do it better. |
Posted By: mlpankey
Date Posted: 19 Oct 2010 at 8:02pm
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Hudsonater I am sticking with the short rod. Talked with Carrillo today . I know your a fan of long rods but increased stoke keeps rod ratios low sleeves cannot be long enough to keep ring flutter and piston stability to utilize a short skirt. We already know that a short rod moves away from tdc sooner . We already know what advancing a cam does for torque and horsepower as well as it open and closes the intake valve sooner so with the longer dwell at bdc we can have 2 to four more degrees of duration which in Siamese intake keeps reversion from happening . We also know that the mountain motors that do battle on the 1/4 mile at 800 plus cubes at 8000 rpms run a 1.3 rod ratio . We all ready know that long strokes like a cam with wide lobe centers . So tell me what I don't know after all we are not building a Indy car motor nor are we building a 9200rpm cup motor. Heres a article written by mine and Larrys came grinder.
http://www.iskycams.com/techtips.php#2005 - http://www.iskycams.com/techtips.php#2005
Also do some asking around I think you will be surprised by who and how many 226 tractor pullers/ builders use that buda rod. To clarify WE its me and you. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: DaveKamp
Date Posted: 19 Oct 2010 at 10:33pm
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In free atmosphere, and at stoichiometry, methanol combustion occurs at a higher flame speed than gasoline, however, when you're feeding an engine large volumes of methanol, a substantial chunk of that incoming fuel is NOT atomized, so you don't have stoich... you have 'wet' fuel. If you put an observation camera inside the chamber, and measure flame speed under running conditions, you'll see that under said conditions, the effective flame speed is SLOWER, simply because the 'wet' fuel slows the flame front down. One of the advantages, is that methanol, burning in the chamber with a 'wet fuel' state, can be started early, and will maintain a burn as long as the fuel continues to heat and atomize. In this case, a long-rod engine will make better use of methanol's extended burn time, you'll lose less energy to high rod-angle piston scuff, and won't be rubber-banding the crank as much, so I'd be inclined to go with Hudson's suggestion. Added bonus to the long rod, is that the G-forces subjected to the upper half of the reciprocating assembly are dramatically reduced. If you're intent on spinning it fast, that's a prime way to keep it from coming unglued. If you look at the data shown in the table below, you'll see that the vapor pressures, heat of vaporization, and net heating values are substantially different... so methanol is a totally different planet. And on another side note- notice the ignition energy required... methanol requires LESS (at stoich) than gasoline... Methanol Ethanol Unleaded Gasoline RON 106 107 92 - 98 MON 92 89 80 - 90 Heat of Vaporization (MJ/kg) 1.154 0.913 0.3044 Net Heating Value (MJ/kg) 19.95 26.68 42 - 44 Vapour Pressure @ 38C (kPa) 31.9 16.0 48 - 108 Flame Temperature ( C ) 1870 1920 2030 Stoich. Flame Speed. ( m/s ) 0.43 - 0.34 Minimum Ignition Energy ( mJ ) 0.14 - 0.29 Lower Flammable Limit ( vol% ) 6.7 3.3 1.3 Upper Flammable Limit ( vol% ) 36.0 19.0 7.1 Autoignition Temperature ( C ) 460 360 260 - 460 Flash Point ( C ) 11 13 -43 - -39 |
Posted By: mlpankey
Date Posted: 20 Oct 2010 at 6:44am
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Piston skirt scuff from side loading . Heres a fact .been running since 2000 either a international rod 7.25 long or the buda rod 7.375 long on the same arias 4 1/8 bore forged piston with same piston pin location and skirt length. Creates a 11.1 cr on the 7.25 rod and a 14.1 on the buda rod with a 4 1/8 bore. I currently sold these pistons to another individual this year but they had no skirt scuffs at all nor had the ring lands opened up any. Also we run a closer plug gap with methanol a msd 7al 2 box the six doenst have enough energy and we run less total timing . Due to the faster flame speed than a race gas of the same Ron/Mon rating for a compresssion ratio of 15.3 to 16.1 . The article above compared apples to oranges .Since you run twice as much methanol as gasoline you have a cylinder cooling affect but you also loose intake runner space for incoming air so you have to utilize the extra duration on a cam shaft and create as much depression under the intake valve as you can . Its kinda like Grumpy Jenkins said . When the engine runs better than your thoughts you need to change your thought process and not the engine. I just need to find a little more longivity in superior products rod material and not back the power down to have longivity from a inferior material. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Bob D. (La)
Date Posted: 20 Oct 2010 at 7:39am
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Panky, Not knowing even 5% of what you know about these mods, my question is this: When you get a rod that holds up to these parameters, what is going to break next. Of course, it will be either nothing or the next weakest link. How much damage might that cause? ------------- When you find yourself in a hole,PUT DOWN THE SHOVEL!!! |
Posted By: mlpankey
Date Posted: 20 Oct 2010 at 7:41am
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Not all methanols are created equal as well.
Methanol Fuels for Racing VP offers several types of methanol racing fuels, each of which offers top quality for applications ranging from drag racing, circle track and road racing to off road and powerboats. Among the most important features of VP’s methanol products is consistency in production and pack- aging. Much of the cheaper methanol on the market is reclaimed from industrial processes and far more likely to contain contaminants. VP doesn’t cut corners or ‘reclaim’ methanol. While that leads to slightly higher prices, our customers can trust our product and have much greater assurance they won’t have to deal with “bad fuel” issues. Why offer three types of methanol? VP has always emphasized giving our customers options. We try to make sure we always have the absolute best performing option available, making the most power possible given an application’s parameters. But there are other considerations—budget, fuel rules, or environment for example—that sometimes dictate the selection of a fuel other than one that makes the most power. M1TM - M1 is the best straight methanol on the market. No frills, but consistently 99.85+% pure and always packaged in lined drums, as are all VP fuels. That means no contaminants and peace of mind from knowing you don’t have to deal with fuel issues. When fuel rules require the use of straight methanol with no additives, M1 is the best option. M3TM - M3 contains combustion and lubrication additives that improve vaporization and increase burning speed. These factors, combined with a better seal of the rings due to the lubrication additive, make substantially more power than straight methanol—up to a 50 Hp gain in a 1030 Hp engine. The improvement in throttle response is also significant—up to a 5% increase in torque across a wider rpm range. On-track results indicate a .02-.03 improvement in ET in the 1/8 mile. The improved combustion also helps the thermal efficiency of the air/fuel mixture. This expands the range of ignition, contributes to better ‘startability’ and more consistency run to run, while lowering the exhaust temperature 40-100°. Not only will M3’s improved combustion make more power and offer better protection against detonation, it also inhibits the noxious fumes you typically get with standard methanol, so it’s much easier on your eyes and nose. A somewhat unexpected benefit of M3 is a 30% decrease in fuel consumption. That means if you typically use 40 gallons over a race weekend, you’ll only need about 25-30 gallons of M3. M3 also includes an anticorrosion package, so there’s no need to add anything else to address lubrication or corrosion issues. To maintain the original properties and comply with Health and Safety regulations, this fuel should be handled and stored in a cool place and always maintained in tightly sealed drums.
Since M3 is not make more power than M3, while offering the same or better protection against detonation. Like M3, M5 offers a wider range for tuning, as reflected by the fact that the bracket racers who have helped us in testing have experienced no problems with tuning or tuning consistency. M5 also reduces noxious methanol fumes, although not as well as M3. That means that while M5 is the best choice for making the most power in unrestricted applications, M3 will still be the best option for some venues, notably enclosed stadiums. M5 is not pure methanol and won’t pass a water test. M2TM Upper Lube – Designed for use in methanol-powered engines, M2 protects valves, guides, cylinder walls, fuel pumps and aluminum fuel systems, and extends pump life. Using electrochemical plating technology—a big improvement over just using oil—M2 leaves a thin film of lubrication to protect against corrosion between races. Recommended for use with M1 or any other standard methanol, while it’s not required with M3 or M5 due to their lubrication additives. Technical questions on applications and tuning can be referred to VP’s Technical Department at 812-878-2026 or tech@vpracingfuels.com. VP’s methanol products can be ordered via any of VP’s regional distribution centers, contact information for which is available on VP’s website at vpracingfuels.com. VP’s methanol products are available in 5-gallon pails and 54-gallon drums, as well as bulk. The four most important properties of racing fuel ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: mlpankey
Date Posted: 20 Oct 2010 at 7:45am
------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Amos
Date Posted: 20 Oct 2010 at 7:53am
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I have had my bad experiences with weak parts when I was much younger. You have a vast knowledge, everyone who has replied to this thread,and I have been absorbing the information I have read here. Only thing I really want to do is see your tractor run, as I am pretty confident that it will run real well, when it is repaired of course.
One thing I can tell you about titanium rods is they will break if you get things out their proper settings, especially ignition timing problems. That was a very expensive lesson I learned. They were a lot cheaper back when I bought them as compared to the price I saw you post earlier.
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Posted By: Butch(OH)
Date Posted: 20 Oct 2010 at 9:20am
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Posted By: mlpankey
Date Posted: 20 Oct 2010 at 9:40am
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To add to the Rehr Morrison article Darrin Morgan who was their cylinder head guru thats now with pro filer. Said that the deck height was 8.090 which was shorter than a sbc and that was the single speed secret It simply straighten the intake runner on v8 engines which made for shorter pushrods which eliminated valve train flex issues and shorten connecting rods. Big block chevy production blocks deck heights are passenger 9.800 truck 10.200. Thats what I remember from the article they have a book on producing power thats published it even calls bs to the bs myths. Then they will be those who allude you that power producing techniques for automobile internal combustion engines dont apply to a tractors internal engine. The mechanical engineering and physic formulas are for a internal combustion engine. No disclaimer on application. PS you big block ford fans Jon Kaase when asked about rod ratios and piston speed said , I dont bother looking at it If I did everyone of them going out the door would frighten me. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: mlpankey
Date Posted: 20 Oct 2010 at 10:10am
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Here is another good article for gear heads like me to enjoy.
http://www.enginebuildermag.com/Article/4123/stroker_tips_from_the_pros.aspx - http://www.enginebuildermag.com/Article/4123/stroker_tips_from_the_pros.aspx ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Larry(OH)
Date Posted: 20 Oct 2010 at 10:43am
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So Butch, the old "A" have short rods in it then??? ------------- '40 WC puller,'50 WD puller,'50 M puller '65 770 Ollie *ALLIS EXPRESS contact* I can explain it to you, BUT I cannot understand it for you!! |
Posted By: mlpankey
Date Posted: 20 Oct 2010 at 11:10am
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to yield a 1.5 rod ratio on a 6 inch crank means the rod would be 9 inches long take 1/2 the stroke which is 3+9=12 inches . The blocks deck height is 12.656 so now you have to have ..440 thousandths including the head gasket for a compression ratio of 15.3 .1 so you have a piston of a compression height of .258 ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Butch(OH)
Date Posted: 20 Oct 2010 at 11:22am
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Posted By: DaveKamp
Date Posted: 21 Oct 2010 at 8:29am
Back to the first photo- what we're looking at here is a rod failure, not questioning the ability to 'make power'. Evidenced by the photo, it takes no forensic talent to determine that the load subjected to the rod, was greater than the rod could withstand. The question, is what aspect of loading caused the rod's modulus to be exceeded. The first and foremost condition which would cause a failure of a structural element, is when that element is subjected to load which does NOT evenly distribute upon the element's section modulus. Take a 40' piece of I-beam, and lay it across sawhorses, first vertically then horizontally, and you'll see that in each plane, there is a certain amount of deflection that occurs due to the beam's own weight. You'll also find that if you add a certain amount of weight to the center of that beam, it will deflect by a certain distance. This is called ELASTIC MODULUS... and you can predict that if a given weight causes the beam to deflect an observed distance, that increasing the load by a proportion, will increase the deflection by a proportionate distance. If you attempt this with the beam in both positions, you'll see that more deflection occurs on one plane, than on the other- this is because the I-beam's material is distributed differently with respect to loading forces. If you repeat same test, with a structural shape other than I beam... say... square tubing, or round tubing, you'll find that the same deflection occurs, BUT... since the shape is symmetrical, deflection is the same regardless of which side is up. IF you continue to add load to the shape, eventually, you'll exceed the material's tensile strength, and some part of the shape will fatigue. Logically, the area of section modulus that fails FIRST, is the part which is farthest from center of axis... because the geometry of deflection causes stress to occur there first. Now, take that I-beam, place one end on a sawhorse and clamp it down. Put the other end on the sawhorse, but twist it 90 degrees, and clamp it down flat. Now put a load in the middle. It will deflect, just like before, but it will fail much sooner, firstly because the deflection load is irregularly distributed about the shape, and secondly, because the material is under inital stress of torsion PRIOR to accepting the actual load. Now where's this all going? It goes right back to what Grumpy said about observation vs. analysis: What you observe, and what you attempt to predict, are two different things, and what you Observe, can Quantify, and predictably Repeat is ALWAYS correct. The conclusions here are clear: 1) The existence of stress caused rod failure. 2) Only one rod appeared to have failed... 3) SOMETHING about the crank and other rods appeared to be bound. #1 is obvious... with added note that the rod did not separate. #3 suggests that observation #2 is errant- either the crank, other rods, or block has stressed. Next: 4) The stress which caused rod failure, is a composite stress of ANY AND ALL forces applied to rod. This includes A: Compressive, down the centerline of the rod B: Torsional, twisting of the piston with respect to the rod (i.e. crank deflecting under load) C: Lateral, a sideways load of the big end vs small end (i.e. crank moving forward in block) D: Tractive: rod pulling against piston (i.e. high rate-of-change-of-velocity of piston) When designing a mechanism, you can't design based solely on the forces you INTEND to have occur- you must design based on what occurs as a result of ALL FORCES. This includes twisting of the block, crankshaft, cam, clutch... everything. This also includes G forces from piston speed. My reference to rod length, first and foremost, is to respect the fact that a short rod length results in a greater deviation from zero thrust angle, and a higher rate of change of velocity. In many applications, this isn't a problem, particularly where a rod can be made large, and beefy enough to withstand all stresses, and still be slow enough in Dv/Dt to prevent the composite stresses from resulting in failure. In the case of this scenario, my gut feeling is that, under load, you're generating enough deflection, so that the COMPOSITE stresses are causing the failure... meaning... WITHOUT any deflection, I'd bet that rod would hold up just fine, and probably to a bit more, than what you're subjecting. Lowering the thrust angle, however, provides more 'compliance' in the reciprocating assembly to allow TOLERANCES to mitigate deflection. |
Posted By: mlpankey
Date Posted: 21 Oct 2010 at 9:29am
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Dave I will keep you posted. Since we line bored honed and trued everything in the block I have the measurments I started with and when I get time . When this refueling outage is over I can take the time to remeasure the block . Chuck the crank in the crank grinder and give it a thorough look over. Keep in mind the 262 rod was only used in 262 allis went to a totally different rod for the increased hp of the 301 in different turbo application. I have well exceeded the rated hp for the 262 at 1 hp per cfm of cylinder head flow. well exceeded the cubic inches and turn it nearly 2 times as many rpm as it was rated at under load of the sled. Next challenge is to get 2 hp per cfm which will equate to 1hp per cubic inch. I think then we can reduce flywheel weight to 38lbs and see the torque and hp cross. I think after looking at carrillos order form they are alot of factors I didnt take into consideration when choosing the buda rod . I simply used the monkey see monkey do rule.
------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Brian Jasper co. Ia
Date Posted: 21 Oct 2010 at 10:10am
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All I'm going to say is interesting. Keep us thinking and posted. ------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: ALinIL
Date Posted: 21 Oct 2010 at 6:45pm
| I have a few questions. I assume you had the crank, flywheel and clutch assy balanced? Did you then have the rotating assy (rod, piston assys balanced). What did a teardown show after a engine dyno run that simulated a sled pull? You are probably correct that the rods are a little weak. If only the no1 rod bent, it may have started with the crank flexing. Also do you use a harmonic balancer? |
Posted By: Larry Miller
Date Posted: 21 Oct 2010 at 7:56pm
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Sheessse -- Who doesn't know this stuff ???? ------------- I used to be young and stupid, now I am not young anymore. |
Posted By: mlpankey
Date Posted: 21 Oct 2010 at 8:06pm
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No. 3 rod is the one bent in the picture. Dynoed on a automotive chasis dyno in acceleration. no tear down. rods and pistons were balanced to the tenth of a gram . As mentioned before inline engines dont require addition of bob weights on the crank as v style engines do . removed weight from flywheel added weight to front pulley we utilize it as nothing but a hub and balance.clutch pressure plate were balanced to neutral. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: DaveKamp
Date Posted: 24 Oct 2010 at 2:28pm
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Couple of notes for 'ya here, Mitch: The de-facto standard 'text' for any internal combustion engineering student is "The Internal Combustion Engi8ne in Theory and Practice, Volume 1 & 2, by Charles Fayette Taylor... Surprisingly, it wasn't a required text in any engineering classes, but if I were the professor, I would certainly require a front-to-back read for every mechanical or thermodynamic engineering sophomore. It's published through M.I.T. Press, ISBN 0-262-20051-1 (hardback) and 0-262-70026 (soft). But my apologies for taking so long to come back with the details- I was on business in Houston and Phoenix, wanted to have the text in front of me so I'd give you pointers to the correct page. In any event, this pair of books is absolutely golden, as the technical description of engineering factors steps far-and-above what an everyday hot-rodder will divulge in a competetive environment. I think the best reference to the situation you've found, is in Volume II, pages 496 through 498, it describes the stresses and mathematics of crank deflection. Page 503 has a few paragraphs on how crank deflection and cyclic balance affect alignment, and take into consideration tolerances for rod/stroke ratio. I have little doubt that your filled block is maintaining dimensional integrity, save for whatever thermal expansion occurs. I think what's happening, is that your crankshaft is acting like a 'rubber band', and is flexing far enough to cause the rods to get catty-whompus'd, hence, the bend starts, weakening the rod. A stiffer crank would help solve this... geometrically a longer rod would help, and one other thing (which may seem bizzare) is running higher clearances at the big and small ends of the rod, so crank thrust or deflection are more 'tolerated'. I know that 'billet' is a common term, but it's frequently, and for some reason popularly mis-used... 'billet', from a metallurgical and manufacturing definition, is a 'raw' state, not rolled, just poured into a slab and trimmed to rough dimension... basically a shaved ingot. Those main caps are probably much more- they've likely been cut from rolled steel, which is akin to forging, but rather by compacting through a rolling mill, it has a much higher strength than just a slice of 'billet'. And a couple of question-ish comments... You refer to 'conservation of energy'... you're not dealing with a drag-race engine, so many of the concepts found in that type of competition don't apply, and some of them are actually totally counterproductive. For example, in a drag-race application, you can have a lightweight car, perfect gears, and incredible torque numbers, but an engine with too much rotational inertia will not be competetive because the engine cannot move through it's RPM range fast enough to accellerate well. Furthermore, you want a drag-race motor to have a wide powerband, that is 'peaky' enough to give a good hard push at 'both ends of a gear'. In a pulling application, there is no benefit to having an engine that can change speed rapidly... instead, you WANT it to hold it's speed... so having high rotational inertia is a GOOD thing. Next, you want a powerband that will be strong from governed speed all the way down to the point where you'd spin out or kill it. I'm perplexed as to why you'd use an inertial chassis dyno. I think it'd darned near an international law that every third tractor show has a guy who brings his old M&W hydraulic PTO/Belt dyno... I know our local group (Deer Valley) has one in tow just about everywhere, and guys put their iron horses on 'em to see how well they're doing. An intertial chassis dyno, for all respective purposes, tells nothing other than how the engine and powertrain fare with respect to accellerating a given weight of vehicle to a given speed. Horsepower numbers are CALCULATED, not measured... so following the chassis dyno's data as a method of checking your work is misleading at best, and counterproductive at worst. Really, the horsepower and torque figures of your engine are irrelevant... I think a better way for you to do it, is to find a 100' stretch of dirt, and find something really big to tie your tractor to, and then rig up a makeshift sled... and just drag it back and forth, throw some more scrap metal on it, 'till you can't pull it... then find a way to make it pull. MY test-sled is an old hydraulic press... came from a railroad maintenance facility, they used it to press wheels, brake disks, and bull-gears on/off locomotive axles. It consists of about 12,000lbs of steel, sitting on a 6' square steel plate, and I've thrown another 1000lbs of steel scraps on it. While it doesn't give me a comparison against an actual manned sled, it gives me an excellent frame-of-reference as to how my WC, WD, D17 and B pull, and of course, when loaded to limits, what the tractor's reaction to load IS... then I make corrections, and try again. The only thing to keep in mind, is to keep ALL the pulling conditions constant, while making measured changes in just ONE factor, that way, one can correlate factorial changes to measured results. This also gives a certain amount of guarantee that if failures are gonna occur, they occur in your backyard, rather than on the track. |
Posted By: mlpankey
Date Posted: 24 Oct 2010 at 3:53pm
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We have a test sled we drug it around Thursday before going to the pull on friday. We drug it thursday at a lesser rpm than we drug the sled friday because we had gov weights together holding the rpms down thursday . they exploded friday night and our rpms went even higher than we had ever seen them do to the tires unloading allowing the engine to see no load on friday. heres a calculator for flywheels. As for the chasis dyno being unproductive I wouldnt say that .I have yet to see a wide band meter you could hook to the tractor supplied on a pulling sled or a lab top maping timing curves. two things increase torque flywheel diameter and the engines power output. Now just when does the 300 lbs a piece tires and wheels 53 inches tall tires wheel speed affect torque.
http://www.botlanta.org/converters/dale-calc/flywheel.html - http://www.botlanta.org/converters/dale-calc/flywheel.html ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: mlpankey
Date Posted: 24 Oct 2010 at 4:28pm
------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: DaveKamp
Date Posted: 24 Oct 2010 at 8:41pm
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Timing curve, on a governed engine, is totally irrelevant. When you set your advance weights, they're either in, or out. Engine speed is either above (advanced) or below (retarded)... if you're operating in the interim range, you're not 'into' the fat of your torque range, which means you're done with your pull. Yes, friction of a bearing is relevant to cross-section, but only if you have physical contact. You're running bearings that are hydraulically supported in a non-contact state. If you get friction, you'll know, because your bearing shells will be in pieces in the pan. You're dwelling on details that, from a net output standpoint, are totally insignificant. If you were to actually measure, and sum up ALL the friction, including wind drag and oil windage you'd find that, compared to your draft load, the horsepower consumed by friction is a microcosm of dragging a 2' piece of door-chain in the dirt behind the sled. The inertial chassis dyno is an irrelevant reference, because it does not apply a load- it relies on inertia of a spinning drum or disk to 'estimate' power. If you were to put a Dodge Viper on the inertial chassis dyno, you might see 400-500 indicated HP. Put a Kenworth road-tractor on the same inertial chassis dyno, you'll see 100 or so. This is because the road-tractor's powertrain is geared towards pulling an 80,000lb load up an 8% grade... not accelerating a 2800lb load to 160mph in the shortest possible time. You referred to throttle response. In a constant speed, governed engine, there is NO throttle-response. You start your pull... perhaps a bit light on the throttle, and then bring it up to speed... and as load increases, throttle opens fully, and STAYS THERE. Throttle response is necessary for rally racing, where speeding up and slowing down is necessary to compete. It's also required for shifting gears in a manual-transmission. Totally irrelevant for a tractor-pull consideration... almost as irrelevant as throttle-response in a diesel-electric locomotive. Ask yourself: Is the engine within it's powerband? Is the throttle at Wide Open? If either of these are "no", then you're either not hooked to the sled with the very immediate intention of winning, or most of your engine is laying on the track, in a big oil slick. The #1 determining factor of how well you'll do in ANY tractor pull, is defined by the amount of weight on your driven wheels, the diameter of your driven wheels, and the amount of drag induced (including drag which occurs from your non-driven wheels). Once you've reached the limit of your tractive effort, the additional drawbar pull can only be increased by increasing wheel horsepower by an incredible multiplier. That's the Wismer-Luth calculation: http://www3.abe.iastate.edu/ae342/AE342_2008/Lectures/Traction.pdf So what this means, is you can take a 20,000lb articulating 8-wheel tractor, rip out the V8 turbodiesel, add about 40x more gear reduction, and put a 12hp Kohler underhood, and still drag that sled to full-pull. If it's too much load, gear it down some more. Yes, you can even chain the tractor down and SPIN ALL EIGHT WHEELS with a 12hp Kohler. The drawbar draft will be enormous (about 7500lbs!), and all you'll have underhood is a single-lung thumpin' along at 3600. What WON"T you get? Easy: You won't get FAST. It'll take a week to get down that track... you'll want to use the whole fuel tank, and take turns at the helm, but the nice thing is, you'll be able to sit in there and eat dinner, watch a movie, probably take a nap. Harold (Luth) is a personal friend of mine, he did this study many years ago, when he was early in his engineering career with John Deere Moline. This study wasn't done by proving a theory with casual tests, it was done by extrapolating formulae from empirical data... thousands of combinations of tractors, tires, draft loadings. They used a test-sled equipped with an electronic strain-gauge and a chart recorder to log each one. This was long before 'personal computers, but if I were to repeat his study, I'd do exactly the same, and put a couple of PCs in there to record the strain-gauge data, as well as measure the linear drag on the sled shoe, position of the slug, etc., simply because that level of data density is now available. Matter of fact, I have a few used 50,000lb load-cells (electronic strain gauges) lying around, I could send you one. You figure out how to integrate it into your drawbar, or your favorite test-sled, and wire it to a common weighing instrument, and then come up with some method by which to calibrate it, you could measure drawbar tension as well. Simply for the sake of competition relativity, you could just use it uncalibrated, and use it as your meter to measure draft results. |
Posted By: DaveKamp
Date Posted: 24 Oct 2010 at 8:47pm
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Under governed-speed continuous-load conditions, the flywheel diameter has NO effect on engine torque. None. Take that 12hp Kohler... get 10 ft-lbs at 2200rpm. Put a flywheel on it that's 20' in diameter, get 10 ft-lbs at 2200rpm. Only difference, is that the POLAR MOMENT of the flywheel will limit the rate-of-change of rotational speed of the engine. You're not shifting gears, or cornering through a tight racecourse here. Now, if you compare the small and large diameter flywheel on a BRAKE-type dyno, and measure for a VERY SHORT TIME, the large-diameter flywheel will require more torque-load to change rotational speed, but this is totally irrelevant in a governed application... the whole point, is steadily increasing load under constant engine speed. |
Posted By: mlpankey
Date Posted: 25 Oct 2010 at 7:09am
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So then the compression ratio being the highest you can run for a specified fuel will be the best producer of torque. Ps i dont run weights in the distriutor. I would like to know how much less stress a rod and crank would see with a rod 5/8 longer . It simply moves the rod stroke ratio formula .060 ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: DaveKamp
Date Posted: 25 Oct 2010 at 7:27am
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Best torque isn't necessarily coincident with highest compression... best torque occurs when you completely fill the cylinders. Stretching it out by 5/8" relaxes the geometry substantially... draw it out on a piece of paper, and compare the difference in thrust angle between the rod and piston. Now turn the assembly to the side, and imagine the crankshaft being crooked... and the deflection of the crank being 'taken up' by the connecting rod FLEXING. With a longer rod, the amount of flex required to take up that deflection is substantially lower, so the fatigue point of the rod is much harder to reach. To compare this to something totally different... imagine being a short, squatty dude on a bicycle... where the bicycle has a HUGE crank. Now space that huge crank WAY wide, and pedal it. Pretty uncomfortable, as your hips and knees will be splayed way out. This is what I believe is happening in your engine. Now, take that short squatty guy, and give him really long legs... that splayed motion is now a whole lot less splayed. You could have that block sitting on a granite surface plate, with a dial indicator, measuring an absolutely true crank in the block, with perfect tolerances in main and rod bearings, correct end thrust ratings, etc., but when installed in the tractor, with a sled on the drawbar, throttle open, timing advanced, and scads of wet fuel going into the chambers, that crankshaft looks like a jump-rope on a hot saturday sidewalk in Chicago. Allowing for that to happen is an absolute MUST... 'cause if you don't, SOMETHING is gonna give. |
Posted By: mlpankey
Date Posted: 25 Oct 2010 at 7:39am
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60 thousandths change in ratio is substantle .I would have to see the numbers. I am just that kind a guy. If your statement about best torque is true then best torque would occur at 350 cubic inches instead of the 400 + inches most are building them to. We run race engines clearances thats why we ran the non bypass oil pump ie more clearnce less oil pressure. I quess I should have a billet crank titanium rods and a chilled iron camshaft made for shubnek ceramic lifters with the fouur exhaust ports becoming four intake ports a intake for a 750 holley . I think with another 10 grand in funds I think i could see 400 to 450 hp. After all I built a engine with the same rod same rod stroke ratio as most current builds for this engine are but instead of quiting at 12.1 like most of them do I ran her to 15.3.1 and the rods falled . ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: ALinIL
Date Posted: 25 Oct 2010 at 9:42am
| ML - Not knowing your exact build-up. In order to get a higher deck height, and use longer rods are you using a .25 - .375 deck plate and setting the sleeves ontop of the block? - AL |
Posted By: mlpankey
Date Posted: 25 Oct 2010 at 10:58am
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no deck plate . A deck plate creates promblems of its own . sleeves have interference fit at the engines deck and bottom bore. to run the 5/8 longer rod the piston pin would be in the oil ring. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: M Diesel
Date Posted: 25 Oct 2010 at 6:50pm
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DaveKamp, cool to hear somebody else owns a set of those books. Well I say owns, mine got loaned out to someone who moved away so they are gone now some 25 years ago. I lost interest and never bothered to replace them. Never thought I'd meet someone else who had them. And by the way, no implementation of weights in these engines will ever be balanced. With non-sinusoidal motions you can only move the intercept frequencies above the point that you care, and yet there will always be large stresses at play. Heck, most never stop to think that at 90 degrees crank the piston is not halfway down. Main thing is, is this a 5 bearing block or a 3? |
Posted By: Gary in da UP
Date Posted: 25 Oct 2010 at 7:00pm
| 3 mains. And yes , it is refreshing to hear an educated, well thought out analysis of engine performance theory. Thanks, Dave , I have enjoyed your posts. |
Posted By: M Diesel
Date Posted: 25 Oct 2010 at 8:01pm
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Yeesh. 3 mains and rods that should have "Briggs & Stratton" on them somewhere? That's too funny. Dave, btw hydraulic problems start to occur well before the last bit of air is squeezed flat. A very large percentage of fuel stays in droplet form right up through the burn cycle. (Vaporization is mostly a myth as I see it.) Especially with alcohol. Liquid in the squish zone has been a problem for old diesels since forever. But that is not what happened here. Might have aided a bit. |
Posted By: Steve M C/IL
Date Posted: 25 Oct 2010 at 9:08pm
| The story I heard was that some engineers high speed filmed a 6cyl Deere crank with 7 mains at high rpms and it flipped and flopped like a rubber band.If that's the case,you gotta wonder how these 3 main engines ever stay in one piece! |
Posted By: DaveKamp
Date Posted: 25 Oct 2010 at 9:37pm
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Mitch- there's no replacement for displacement, but the one thing that can replace cubic inches.... is cubic money. Yes, filling the cylinders, and doing it with a perfectly metered, fully atomized mixture of fuel and air... and then touching it off, and having proper chamber geometry to rapidly propogate the flame through the chamber so that maximum chamber pressure exists from 45 degrees ATDC to 135 ATDC, you'll get the greatest amount of torque. A more rigid crank will help. Remember, this is only a 3-main-bearing engine, and while that #1 cylinder is firing, #2 is coming up on compression, #3 is exhausting and #4 is taking a deep breath. That means the FRONT span is flexing down, while the back end is flexing up. And the note about balance is valid- the ideal configuration for a 4-cylinder single-plane crankshaft, is in an opposed configuration... a boxer. An inline four can have good secondary balance (pistons going up vs. pistons going down) but the rods swinging right-to-left have different geometry from those spinning left-to-right, hence a 'primary' imbalance. MD, you're spot on regarding the hydraulic droplet situation... and that's why I posted the excerpt above illustrating differences in properties of fuels. Carbohydrate fuels (which Methanol and Ethanol are) have totally different stoich, vapor pressures, and specific heat, and the carbon-bond energy and effective flame speeds. What makes them substantially different from hydrocarbon fuels, is that they're VERY likely to experience state-change under a rapid pressure rise. Add to the fact that the primary advantage of nitromethane, is that you can dump in over 8x the LIQUID quantity in each power stroke. At high mechanical compression ratios, that's flirting with a hydraulic lockup event. Gasses are compressible, liquids, however, are not. It's easy to observe the result- if you watch a top-fuel dragster in slow motion, you'll see a flame jump out of each pipe, on each successful firing event. When the engine is idling, it'll miss on about every third or fourth cylinder... eventually, incoming airflow will clear out the cylinder and it'll fire again... and residual fuel in the pipe will barf a fireball... good to stay out of the zoomie's blast. It's not until you get the RPMs up a bit, that the air-fuel charge velocity gets high enough to suspend the droplets and generate an effective burn, and once you REALLY have it going, you get a nice little blue/yellow 'bunsen burner' cone going on at the end of the shorties. Reason for the nice pretty blue/yellow cone... only about half the fuel actually burns IN the cylinder... the rest goes out the stack unburned, because available oxygen inside the chamber, is gone. One of the advantages of nitromethane fuels, is that there's enough latent oxygen IN the fuel, to allow it to burn, and it does... but it doesn't burn fast enough. The unburned portion, however, is superheated above auto-ignition temperature, so the moment that mixture hits open air, it incinerates, leaving that pretty flame. Now, if you compare that flame to a sample of methanol that you place in a cup and burn in free atmosphere, you'll see essentially no flame... the burn cycle emits essentially all heat, and no visible light energy. This is pretty dangerous territory, especially when there's a fuel spill on track or in the pits... crews could run right through burning fuel and not know it... at least... not for a moment. Some additives will make a brighter flame, which is good from a safety perspective. |
Posted By: DaveKamp
Date Posted: 25 Oct 2010 at 10:19pm
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But amidst all this, I'll add the caveat that I'm particularly fond of 7 main bearings... I think this'll work: http://www.facebook.com/video/?id=1130541620#!/video/video.php?v=1618395416357 - http://www.facebook.com/video/?id=1130541620#!/video/video.php?v=1618395416357 |
Posted By: Brian Jasper co. Ia
Date Posted: 25 Oct 2010 at 11:36pm
------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: mlpankey
Date Posted: 26 Oct 2010 at 6:50am
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Nitro methanol /topfuel engines are a different breed . I have study and watched them since I was a kid on a 8.90 quick rod crew. The blower itself is capable of making a solid. Because of the oxygen percentage in the fuel you run seven times the amount to gas . On a pass down the track the injectors are spraying the amount of fuel that is equivelent to being in a shower with six shower heads on at 90 psi of supplied water pressure . The iignition system two 44 promag magnetos produce a spark that can be welded with at that time the ignition system can have 50 to 60 degrees advance in it. . This is needed to only ignite the gasoline to start the engine this is the sound when the engine is flat before nitro is introduced and the cackle is heard from the zoomies. Then light the nitro until the engine warms up. After the burnout the engine is warm the electrodes on the plugs are burned off . The spark plugs at that time are like glow plugs and the engine runs until the feul system is shut off. This is alot different than a natrurally aspirated high compression engine that utilizes a high lift cam with duration and overlap to bring in fuel and air mixture. With a cam with sufficient overlap/scavagening affect and a header that leaks or stack in a tractors case that can draw in fresh air any tractor or vehicle will flame out the exhaust. NASCAR entering and exiting turns during daylight hours etc. A 226 engine by the way has no (quench area) where the piston come within .040 or less of the head hence no squish. Closets piston comes to head unless rod grows really large is .400. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: mlpankey
Date Posted: 26 Oct 2010 at 7:15am
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Another thing about nitomethanol is pour some on concrete and stick a lit match to it the match will go out. Take a claw hammer and hit the concrete where liquid is puddled with sufficient shock and if you have a arm and life left be verry thankful. It doesnt like compressive shock. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: mlpankey
Date Posted: 26 Oct 2010 at 3:40pm
------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: wi50
Date Posted: 26 Oct 2010 at 6:45pm
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We've all got our own ideas on how to build an engine, we all have a set of rules to pull by that dictate a max RPM, ground speed or some other limitations. Some of you feel that there is no replacement for displacement. Far from true. Is cubic inches, stroke length, rod ratio or intake flow the most important thing to consider? A fair bit of it will depend on your RPM or breathing (carb, manifold) restrictions.
I feel that one of the single most important factors in an engines potential is the exhaust. If the exhaust can't exit, where's the room for the fresh air charge? Makeing total refinement of the intake port, manifold and carbuerator less important than the exhaust. Some of you have to run with the "stock appearing" manifolds while other rules allow anything to run. A well designed and properly sized header will make more power than any other modification.
Is engine size or displacement important? Yes, but it's not near is important as good breathing ability, build an engine large, and it will only slow down to make it's power when the load comes on. Build one a little smaller and it may well have more peak power, and it may make it at a higher RPM, or have better ability to maintain it's speed when the load comes on. If I can build a 226 Allis to over 400 CID, will it make more power than one that is less than 300 CID? What about one built to 200 CID? Chances are that the 200 CID one is jut to small, but the 300 CID may be "just right". It can have a higer rod ratio that keeps from side loading the pistons, we can have a little more dwell time on BDC and TDC. Some of you feel that dwell time is wasted time, but what about the ability of the exhaust to scavange the cylinder? What about less wasted energy in piston accleaation and deceleration? A higher rod ratio will increase these factors, as well as maintain a better angle putting less stress on the crank and rods.
What is compression ratio? 15:1 is as useless of a number as 11:1. How full can I fill the cylinder? How large of a cylinder and at what speed can I fill ito what percentage? A high compression ratio may be impressive, but it's like boost pressure in a super stock tractor, it's only an indication to how poor our cylinder head is. If I could fill the cylinders to 100% capacity, maybe a 4:1 comp ratio would be all the engine could withstand.
What good is a verry large engine if it can't breathe well enough? Sure the peak torque numbers may be high, but if the RPM is to slow we loose to much ground speed. What is the difference in gear ratios to shift down one or two gears? What increase in engine RPM do I need to be able to keep the same ground speed as I have in that higher gear? In a lower one, my engine RPM can drop and I have lesser chanve in ground speed, also less stress on my parts.
I'm not telling anyone how to build their engine, but I see many factors that people forget when building them.
I'd like to share a couple past experiences. My old 201 Allis engine ( we had to use the old WC-WD blocks for the WC-WD tractors or a D-17 in the D-17, I couldn't use the better D-17 block and crank in the old WC. We have no RPM limet and no carbueration limets other than a single barrel updraft carb at the time, now there is no rule. It's built to 268 CID, verry small. There's a few things that could be improved on, maybe a bit longer stroke and a little less rod length but the combination of parts is a 4" stroke Leroi crank offset ground to 4.125", the rods are customized from a Perkins diesel engine and are at 9.1" length. The bore is 4.5625 because I got a good deal on a pile of forged pistons with a verry low compression height. I won't waste time on the block or head modifications, cam specs, etc. Comp. ratio isn't that high but it breaths well enough to make up for it. We figured out and built a verry good intake manifold, carb, and the exhaust header is tuned and sized to the engine the best a couple dumb farm kids could do. I made a steel flywheel and a double disc clutch assembly with as much weight on the outer mass of the flywheel as possiable. The whole unit was about 125# when finished, my thoughts were that once it was up to speed it would make up for some of the short stroke when the load hits.
I rember going to Iowa one night to run and there was an Oliver 88 there with (going from memory a 540 CID engine). Supposidly at the time $15,000 in the engine from some big name machine shop and was unstopable. I was just hopeing not to look like a fool with half the engine. The Ollie made a full pull and was impressive. I ran in a gear where I figured I couldn't spin the tires, just snuff the engine but I figured it was my best chances, but the dang thing made it out the end also. THe other Allis, M's and 460's didn't. We came back and the Ollie spun out, my engine wound up good and carried it but snuffed, 18 feet ahead of the Ollie. Another night I was at about 180 feet when the spark plug wire fell off ( I had hit it with the side panel and knocked it off the dist. cap), by some stroke of luck we made it past the 88's, M's and the other Allises. Lucky that night. Then I rember a fella that traveled a ways one night and had some big HP numbers and a big displacement Allis, it spun the tires pretty well but the little engine ended up 80 feet in front
Comparing the Allis engines to each other we ran against some friends quite a bit, built to the same set of rules with headers, large carbs, etc. 380 or so CID engines, one was over 400 and there were a few in the mid 300's. Not all the time but more of the time than not the little 268 would get further on the track. I didn't spin the tires that often, it would usually snuff out but it had the ability to get higher groundspeed and maintain it for longer than in a lower gear than the others would in a higher gear.
In a limeted RPM type pulling this engine wouldn't be worth $#@! but when you could let them run it was tough. I'd usually try to have it at 4500 RPM or so on the line, ride the twin disc clutch for a bit and it would usually rev around 6000 RPM, sometimes on the right night it would go well over. Lug it under 3000 though and the fire went out quick.
I need to get it out again and have some fun. I'm working on a D17 engine to have a little fun with for a limeted RPM and 4mph class, it's not going to be huge but with "stock appearing" OEM type manifolds and carb it can't be, or it will just be a dog. I keep weighing out my options and running numbers to see what I want to do, but I'm thingking in the 300 inch range give or take 20 it should be "just right" to have some fun with and not feel bad about useing it a bit on the farm now and then.
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Posted By: mlpankey
Date Posted: 26 Oct 2010 at 7:13pm
At .400 valve lift the intake valve flows 143 cfm the exhaust flows 177 cfm . this is why I said in stock form the turbo for a 201 or 226 making 7lbs of boost would be the single most power adder one could do . Allis engineers realized to get torque they had to restrict the exhaust from being such more free flowing . If you cant get it in it then why worry about getting more out . Best trorque occcurs when the exhaust valve flows out only 85% percent of what the intake lvalve flows. the piston and natural draw from a header tube or stack will take care of the rest. the single best way to get more intake flow from a head on a naturally aspirated engine is to increase cylinder bore. I ran a 310 engine for several years the 360 392 400 plus inch engines most of the time beat it . They had a low rpm torque engines that meant they didnt have to have everything perfect to make a good run as one with a smaller less forgiving engine does. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: mlpankey
Date Posted: 26 Oct 2010 at 7:49pm
------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: DaveKamp
Date Posted: 26 Oct 2010 at 8:58pm
Tractive limits isn't an all-or-nothing situation... but tractive-effort vs. slip has a 'roll-off' curve that's darned near all-or-nothing. If you read the Wismer-Luth study, you'll see where Harold indicates how agricultural traction predictions up to a certain percentage yield essentially full effort (minus rolling losses from tire and ground squish). Once the TEL is reached, slip starts to occur in greater amounts, and when that point is hit, drawbar force SEEMS to have reached it's limit, but there's a LITTLE BIT left... and to get that little bit, you need to add substantially more horsepower. Tractive effort may rise by, say... 0.3%, slip has increased by 10%, and horsepower input has tripled... so there's an illustration of how aggressive that tractive-effort dropoff occurs. Exactly right on the inertia and speed, but inertia of the sled in an inevitable result. Pullers without speed limitations will try to use the sled's inertia to 'slide out' another few feet... sometimes it works, sometimes it plants... depends on the track. Limiting speed is all about safety... you get a sled and pulling tractor going fast, and something gets out of shape, really, really bad things happen fast. Piston dwell at top and bottom ARE the same- it's a sinusoidal motion, because the crank is travelling in (well, in theory) a circle. Dwell Time is the direct result of rod-stroke ratio- a longer rod results in the cosine angle being lower, hence, the transition time (dwell time) is longer than the short-rod motor. RE bore/stroke and compression ratios... there is a point, in any variable, where other variables become a limiting factor and prevent improvement. An example is increasing compression ratio. In a flathead ford, exceeding a certain point causes performance to drop off, because the chamber shape and valve geometry simply cannot flow enough air to make the CR useful... the cylinders won't adequately fill. Similar situation happens when running too much bore, or too much stroke, or too short a rod... too much airflow demand, and the intake, exhaust, valvetrain, and chamber shape simply cannot flow enough to make use of the CR. I built that inline back in 1991... that's a Sissel lump-port, and there's lots of fancy parts in there... built it before meeting Leo Santucci. Never got to meet Jim or Cotton (too young, I guess), but Leo's a great guy. This is a very healthy motor, but I built it specifically for this application- it wouldn't run well in a tractor or road vehicle without some serious changes, and I certainly WOULDN'T run that cam in a tractor... too much overlap, so it won't lug. It pulls very hard from 1100 to 1800, then rediculously hard (rip the ski-bar right out of your hands) from 1800 to 5000. On the down-side, it is capable of breathing well (even with the marine intake and exhaust) to the high side of 7k, but I have to rev-limit it to 5000rpm to prevent melting the drive gears... which I offset with high gear ratios and lots of prop pitch. Amazingly, it has a frumpy, but stable idle at 625rpm, with exhaust submerged, and will shift in and out of gear with no worries. It will run circles around the twin big-block offshore racers that ply the river here... and it'll get 7mpg doing it... (that's really good for a boat) running 89 RON dock-gas on a 95 degree day... and it's still USCG approved explosion-proof and fully corrosion resistant. |
Posted By: mlpankey
Date Posted: 26 Oct 2010 at 9:03pm
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Hey Brian go to wikipedia and search nitromethane top fuel . Dave you really should give credit to all printed resources. As in college plagiarism is not good. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: mlpankey
Date Posted: 27 Oct 2010 at 7:54am
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here is a nice link to poke around in that darrin morgan suggested.
http://raceology.com/2006/01/top-racing-threads-of-05.html - http://raceology.com/2006/01/top-racing-threads-of-05.html ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: wi50
Date Posted: 27 Oct 2010 at 11:59am
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In this thread I've read about piston ring "flutter". Wouldn't a long rod ratio will help cover up the flutter? Just picking out one example of how one thing is alwayse effected by another, so every improvemet we think we make we give up something else allong the way. There's no free lunch. There's likely a point for optimum rod to stroke length, stroke to bore and total displacement but it all revolves around other factors in which we are limeted on. I do see some advantages to short rod engines but I see many dis advantages also, the same true for long rod engines.
You can beleve what numbers you want, but a 4.562 bore, 4.125 stroke and a 9.1" rod with a 1.1" comp height piston with some valve reliefs in it. With an un modified block we are in the 12.7" or slightly less deck height range and the sum of the parts is 12.206" No deck plate needed and the push rods came out of a 426 Allis engine. The length is similar to the stock 201/226 engines and they are a nice substitute without makeing custom ones depending on the valvetrain geometry. Add a head gasket, some valve reliefs, the large spark plug pocket in the old short heads, some modifications allong the way and the comp isn't terrably high, it's over 10:1 but it was not over 12:1 for a static ratio. The cylinder is of pretty small displacement and anyone can run some rough numbers. Crakning pressure on a compression gauge isn't much over 140 psi. Valve overlap and cam design pretty well bleed it off at low speed. We made our own roller rocker arms, posts, shart and rocker girdle.
Why wouldn't a properly tuned and built header make power? People get to worked up over certain flow numbers and forget about mean flow times, velocity, etc. What if the cam was holding both intake and exhaust valves open for a fair amount of time at TDC. Would a good header not use exhaust gasses from one cylinder to scavange the next one in the fireing order? Is that not the point of a tuned header? There's a difference in the collector designes to use and I feel some offer an advantage over others. The siamesed intake port of the head is the biggest restriction we face in the 201/226 engine. Helping to maintin flow direction and velocity with help from a tuned header and a cam that allows such is of a huge help. There's a fair bit of math involved in header design, the work involved in building and testing is probably more work than most wish to try, but it will pay larger gains than any other modification.
A billet cam is easy to make, 8620 steel machines easy and the grinding is about double the $$$ as it is to grind a normal cam. I've made them and while no huge advantage it's not huge work or money.
An engine does not have to be big to make power, it just has to better designed. There's been a fine example pointed out earlier with the 292 chev.
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Posted By: mlpankey
Date Posted: 27 Oct 2010 at 1:25pm
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A 2.2 rod ratio is unheard of . well 2 is figured the best which the 14000 rpm formula 1 boys run for 500 miles. A man with that rod ratio would have to make his cam slow down so his valve timming events at low rpms would be with the crank angle if he didnt they would be way out of whack to say the least .Half of 4.125 is 2.062+9.1+1.1=12.262 blocks i have measured have been 12.656-12.262=.394 now then if you had .042 for a normal head gasket =.436 gives a deck volume of 6.93 that equals 9.5 .1 static cr not counting the spark plug hole area or the valve reliefs wich you dont need being that far down in the hole. Your flow velocity wouldnt be much below 5000 rpms and it wouldnt lug at all wouldnt be any pay backs from advancing the cam either. turn it 7000 and it should breath well . I agree to well design . if I can only produce 1/2 a horsepower per cubic inch then you with that smaller engine have to produce 1 hp per cubic inch to be as good and with all the nascar testing on rod ratios I dont think your 9.1 rod with the max cr being 9.5 static with measurements you stated having that much advantage. If your cam is bleeding it off like you state your dynamic cr would probably let you run tractor fuel the best. Since your a header man heres a article from Jerr Stahl he makes a living producing headers.
http://www.stahlheaders.com/Lit_Rod%20Length.htm - http://www.stahlheaders.com/Lit_Rod%20Length.htm ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: wi50
Date Posted: 27 Oct 2010 at 2:24pm
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I'm not saying the engine is perfect or even close, but it runs good enough for me. One can read all the articles and do all the math, but if it all made sense and everything happened text book, things would be easy, rods wouldn't bend, valves would't break and we wouldn't have to work on anything to improve it. Once in a while we would get to run in a mixed class, 5000 pounds anything goes as far as naturally aspirated engines. The "econo mods" something with a worked over small block chev, mopar, etc. in an old tractor chassis. The real good running M, 460, 77-88, or WC-D17 type tractors would more often than not outpull the "econo mods". I can't put much faith in any calculated horse power numbers, as those automotive engines may have had 400 hp, and us poor tractors only had 100-200 hp, but most often it was more usefull. |
Posted By: mlpankey
Date Posted: 27 Oct 2010 at 2:35pm
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the beauty of building a engine yourself is ts like burger king . you get it your way . Everyone overthinks a certain part and the underthinks another. The great debate for rod length is reduces cylinder wall side loading. Just what is the coefecient drag on a forged aluminum piston against a oil film on a ductile iron sleeve beats the dickens out of me but it doesnt show to be enough to ever so slightly mark up a piston skirt. our cam , headwork, etc works well with large stroke big bore combinations.The buda rods just take a pounding. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: wi50
Date Posted: 27 Oct 2010 at 2:39pm
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one of these winters I'm going to make a billet head for the engine. I've got a pretty fancy CNC mill. Crank'NCrank, yep, just figure it out and start cranking the wheels, though it may or may not work.
There was a fella here that made an overhead cam, alumnium head for his minne-mo. Pretty neat and of course everyone was scared of it, but in reality it wasn't that tough to beat or compete with on any given night.
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Posted By: mlpankey
Date Posted: 27 Oct 2010 at 2:59pm
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Now I would be interested in a aluminum cross flow cylinder head built like a 426 hemi head . As far as valve location and ports . I really dont care if it had a combustion chamber or not . probably rather it not .
but then again if the crank whipping fom just three mains is a promblem then why build a head that could produce more power. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: DaveKamp
Date Posted: 27 Oct 2010 at 11:33pm
What are you insinuating here, Mitch? |
Posted By: mlpankey
Date Posted: 28 Oct 2010 at 9:20am
------------- people if they don't already know it you can't tell them. quote yogi berra |