B engine3 rebuild problems.
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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=10273
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Topic: B engine3 rebuild problems.
Posted By: joegrgraham
Subject: B engine3 rebuild problems.
Date Posted: 29 Mar 2010 at 3:13pm
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Hi all, I am currently rebuilding the engine on my B. Reground crank, new bearings, new pistons, ring and liners etc. All parts have come from Steiner. The piston are 3 7/16 flat tops instead of the original 3 3/8 dished type, and the liners came in the same kit. I have got the bearings all set up, and the crank spins sweet, but, once I fit the rings, it goes real tight, and then when I also fit the head and the plugs, the compression is ridiculous, I can only just turn it on the handle and the starter hasn't got a chance. I've pulled it all apart several times now, and I have triple checked the timing is right, and everything is right and it's driving me nuts! The only thought I've had is to fit two head gaskets to lower the compression, and to use a big diesel battery to start it, and hope it loosens up with use, but any suggestions would be gratefully received. Many Thanks, Joe. ------------- If it seems like a good idea, do it. It's easier to apologise than to get permission. |
Replies:
Posted By: mlpankey
Date Posted: 29 Mar 2010 at 3:17pm
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sounds like not enough piston to cylinder wall clearance . did you check it if so how much did you have also what was youre rings end gaps ? ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: joegrgraham
Date Posted: 29 Mar 2010 at 3:30pm
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The ring gap is within tolerance, as the pistons and liners are all new, surely the clearance should be correct? ------------- If it seems like a good idea, do it. It's easier to apologise than to get permission. |
Posted By: mlpankey
Date Posted: 29 Mar 2010 at 3:36pm
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did the liners have a honed finish to them? are you sure its not in the rod bearing clearnce and you got the rods turn correctly. they have a offset which makes two go one way and the other two go turned the oposite. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: joegrgraham
Date Posted: 29 Mar 2010 at 3:59pm
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The liners have got the cross-hatch finish to them, and the rods are correct, long offset facing away from nearest main bearing. ------------- If it seems like a good idea, do it. It's easier to apologise than to get permission. |
Posted By: mlpankey
Date Posted: 29 Mar 2010 at 4:20pm
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if numbers 1 and 3 long side of the bearing toward the flywheel and numbers 2 and 4 are toward the timing gear . thats correct . how much clearance was on the rod bearings. did you measure it or plastigauge it? somethings definately wrong I would remove a piston at a time and see if it gets free. It could be one or collective making it tight but the engine should be able to be turned over by hand with all four pistons and the head off it . You also mention the compression . did you advance the cam when you put it in by accident maybe? ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: joegrgraham
Date Posted: 29 Mar 2010 at 4:26pm
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I was extra careful to get the cam spot on, I'll have to go out tommorrow and go through the pistons one by one. Many Thanks. ------------- If it seems like a good idea, do it. It's easier to apologise than to get permission. |
Posted By: Dick L
Date Posted: 29 Mar 2010 at 6:35pm
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Surely new pistons and rings would be correct. Not on your life. Rings need to put down in the hole and checked with a feeler gage. That is unless you have never made a mistake. they probly came from China. Not often But I have found a wrong package of rings in a engine kit bought from NAPA. How close to the two thousands clearance were you able to get with the plastigage on the rod bearings? |
Posted By: Steve in NJ
Date Posted: 29 Mar 2010 at 8:56pm
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When I did my B motor years ago, I had to do ALL the end gaps! Never assume it should be correct just because its a "kit". Mine was also a kit. I had to match everything to each hole. Spun nice once everything was to spec via the assembly manual. Took Dicks suggestion at the time and skinned .080 off the head also. Like Dick mentioned, make sure all your clearances are correct on the rods n' mains. Somethin's not right.... Steve@B&B |
Posted By: Freewheelin
Date Posted: 29 Mar 2010 at 9:35pm
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Joe,
Whatever you do don't force it. You have too much time and $ invested. Check the rod bearings and ring tolerances as the others have recommended. Unfortunately China is supplying a lot of parts these days and they can't even spell process control.
Take your time. You'll find it.
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Posted By: steve(ill)
Date Posted: 29 Mar 2010 at 10:03pm
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if you can spin the crank before put in the pistons, you need to narrow down if it is the rod bearings or the rings. loosen the rod caps 1/2 turn so you have a few thousands clearance in those 4 bearings, then try to rotate again. If still tight, its in the rings. I have seen rings contribute quite a bit of resistance even with the end gap right. Sometimes its just drag aginst a rough bore... but you should still be able to turn it, and starter would be no problem in turning. ------------- Like them all, but love the "B"s. |
Posted By: joegrgraham
Date Posted: 30 Mar 2010 at 2:13pm
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Hi again, just removed the pistons. The ring gap is around 0.015, the manual quotes between 0.007 and 0.017 (although that figure is for 3 3/8 and not the new 3 7/16 pistons, would that make a difference?). Also, the gap between the piston and the cylinder wall is between 0.010 and 0.015. I checked this against an old piston and liner, and that one measured the same. One thing I did notice is that the old piston slides through is liner by hand, but the new one has to be tapped through. ------------- If it seems like a good idea, do it. It's easier to apologise than to get permission. |
Posted By: ZAK.S.UK
Date Posted: 30 Mar 2010 at 2:33pm
| Hi joe if you cant find anything obvious get hold of mark everret he is in your neck of the woods he will be able to help im sure. |
Posted By: everett048
Date Posted: 30 Mar 2010 at 4:09pm
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I may be wrong on this but 3.3/8 inch with simple working out = 84.65 mm
3.7/16 inch = 86.00 mm
difference = 1.35 mm
or as near as i can figure if i am incorrect please tell me so wrong pistons for sleeves???? hence why engine is tight?
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Posted By: Dick L
Date Posted: 30 Mar 2010 at 5:36pm
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Those are the (details) of checking parts before. .0015 to .002 is the clearance you want. That lets the piston slide thru the liner. The liners could be out of round. Close enough to work by honing the sleeves. Bad enough to return to the seller. The rings are within spec but on the wide side of the specs. That takes hours off the total run time before another overhaul. |
Posted By: mlpankey
Date Posted: 30 Mar 2010 at 6:45pm
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sounds like the sleeves need honed some more . the sleeve should be around .006bigger than the skirt of the piston. a .006 feeler gauge should slide between the skirt and cylinder wall.As for the ring end gap I would rather be on the larger side than the tighter gap. The reason the old pistons slide in and out better is they have been ran and the heat shrinks them to a undersize value and its .062 smaller. something is not adding up to me the old pistons are 62 thousandth smaller than the new ones . but with one of the new rings stuck into the cylinder and pushed down below the deck 1 inch with the old piston to ensure the ring is square you can stick a .015 thousandths feeler gauge between the rings gap. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Chalmersbob
Date Posted: 30 Mar 2010 at 8:50pm
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I think that you should run a deglazer through the sleeves before installing the pistons.
That is what I was taught to do. You could also have a rod cap on the wrong rod. Don't ask me how I know that can cause the crank to be tight. Bob
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Posted By: steve(ill)
Date Posted: 30 Mar 2010 at 9:04pm
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your parts were not quality made. you should have .007-.010 ring gap on a new motor and .017 or so when it wears. Your already at .015 ... that will work, but too much for new....... Next, you piston should have .006 -.007 clearance to the liner. Yours has .015, that is too much, but the piston is tight in the bore meaning the bore is not round ! YOu can hone it MORE, but if your readings are right it is already too big.... THE circumference of a circle is 3 x the diameter , so if your bore was .010 instead of .015, that .005 smaller bore would make your ring gap .015 LESS which would be tight and you could file the end to fit................ basically they screwed up your liner bore, too big, and not round. ------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 30 Mar 2010 at 9:05pm
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Honing the bore a couple thousands would make the pistons slide thru and that will work... but your making your ring gap bigger all the time. ------------- Like them all, but love the "B"s. |
Posted By: Dick L
Date Posted: 31 Mar 2010 at 6:17am
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Sorry Fellows but you ain't putting any new pistons that diameter in any of my engines with a .006 to .007 clearance. I was wrong on the .0015 to .002. I was thinking about the shim stock used over the clearance to check the clearance which is not the same thing. The Allis Chalmers chart calls for .0025 to a max of .0045.  |
Posted By: CTuckerNWIL
Date Posted: 31 Mar 2010 at 7:39am
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I agree with Dick. Piston clearance is the difference between diameters of the OD of the piston and ID of the sleeve. Sliding a .006 feeler gage down with the piston does not show .006 clearance. I think I would take an inside mic and check each cylinder for roundness. Check at least 3 places on each level and at least 3 different levels. And while you are that far, mic the pistons six ways from Sunday. They could be out of round although not too likely. ------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: BrettPhillips
Date Posted: 31 Mar 2010 at 7:50am
| Charlie and Dick have good points. Also, those who say that you have too much ring gap are correct, but in your case this is not likely to be a factor in making the engine too tight. Also, please remember that the piston skirts are not round, nor are they supposed to be. Pistons are almost always cam ground at the skirt for a tighter fit at right angles to the wrist pin. This may have a lot to do with why the old pistons fit easily, as they may be worn round or nearly so. |
Posted By: Ken in Texas
Date Posted: 31 Mar 2010 at 9:53am
| This happened to me once. I had the thrust bearing lock up the crank when tightening it down even with a correct plastigauge reading. The problem was, the crank when turned got left with a small gullet on the journal next to the gear. Solution. Shaved the front edge of the bearing with a pocket knife so it cleared it and went on from there. |
Posted By: joegrgraham
Date Posted: 31 Mar 2010 at 2:06pm
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Hi again guys. Many Thanks for all your input. I'm beginning to think that the kit was manufactured by Mickey Mouse (or his Chinese cousin). I did some measuring today, and the liners are out of round by between 0.007 and 0.010, it's too cold in the shed today, so I haven't done any more, but I'm beginning to suspect the rod bearings are not what they should be either. ------------- If it seems like a good idea, do it. It's easier to apologise than to get permission. |
Posted By: mlpankey
Date Posted: 31 Mar 2010 at 3:53pm
------------- people if they don't already know it you can't tell them. quote yogi berra |
CTuckerNWIL wrote:Posted By: kev/ont
Date Posted: 31 Mar 2010 at 8:39pm
| Another thing to consider is the sleeve o-rings. I have seen in the past where an o-ring can roll when the sleeve is installed that will put the sleeve out of round enough to tighten the engine right up. |
Posted By: steve(ill)
Date Posted: 31 Mar 2010 at 9:04pm
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if you distort a steel liner by pushing it into a B block or getting the o-ring cauage, your not doing it right. THe steel liner will drop into the block with just hand pressure or less. AFter the o-ring is installed, you mught "push" it a little harder or tap with a mallet, but your not pushing NEAR hard enough to distort the liner.... Those lineres were BAD when they arrived unless you beat them in with a 5 pound hammer... was the block clean when you "slid" them in????? ------------- Like them all, but love the "B"s. |
Posted By: SteveC (NS)
Date Posted: 01 Apr 2010 at 1:44pm
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I once tried fitting USED liners and pistons w/rings into a block that had been frozen with water (no anti-freeze) in the jacket. I used new o-rings but had a devil of a time seating the liners into the block. Once I got around to fitting the pistons they tightened up like a frogs ear. I was lucky I only got that far because in the tear-down I noticed cracks in the block so even if I coulda got it stareed it wouldn't have run long.
I did, however, take another block out of inventory and assemble it and it's still running in my B today.
So, it could be a distorted block, key is , like steve(ill) said, if you've gotta push in the liners with too much force, somethings wrong.
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Posted By: joegrgraham
Date Posted: 01 Apr 2010 at 2:44pm
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The liners went in without too much fuss, pushed in with the thumbs and just a little tap to seat them, so I think they must have been bad to begin with. ------------- If it seems like a good idea, do it. It's easier to apologise than to get permission. |
Posted By: Dick L
Date Posted: 01 Apr 2010 at 3:22pm
| All Wet Sleeved Engines no matter the make or size, you need to be able to set the sleeve down without an O ring and turn it 360 degrees by hand. If you can not turn them by hand they are not fit correctly. Wet sleeves are not a press fit. If they were you would not need O rings. Fit them properly and let the O ring do its job. |
Posted By: mlpankey
Date Posted: 01 Apr 2010 at 3:52pm
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I still think its a rod bearing issue but i have heard of the wrong depth of ring being sent for the piston suplied . a 350 kit came with shallow grove pistons and deep grove rings once. ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: Brian Jasper co. Ia
Date Posted: 01 Apr 2010 at 7:19pm
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When I rebuilt my CA 10 + years ago, I ran into a problem with the main bearing bores. The bearings all showed .002 with plastigauge, but the crank would not turn with the caps tight. Having the block line bored fixed that problem. Another thought that comes to mind is connecting rod bearing bores. If the rod bearing bores are not true, that might contribute to the bearings showing .002 clearance on one side but still be tight. None of the rods are bent or twisted are they? Doesn't take much bend or twist to interfere. ------------- "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: steve(ill)
Date Posted: 01 Apr 2010 at 9:18pm
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he said he had to pound the pistons thru the liners--- the liners are obviously out of round and the main problem. Besides that, they are bored oversize. ------------- Like them all, but love the "B"s. |
Posted By: joegrgraham
Date Posted: 02 Apr 2010 at 3:03pm
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I've found the problem!!! The liners were out of round, due to a previously un-noticed crack in the webbing between cylinders 1 and 2, which was distorting everything. Luckily, I've got a spare block. In my defence, this is the first engine I've ever done, it's a hell of a steep learning curve, and I'm pretty much making it up as I go along!, but, thanks to everyone who's posted on this thread, I've learnt a lot of good tips and information, so hopefully, I should get it right this time. Thanks again everyone. ------------- If it seems like a good idea, do it. It's easier to apologise than to get permission. |
Posted By: tbran
Date Posted: 02 Apr 2010 at 3:20pm
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I would put one piston in at a time till problem occured, check to see if wrist pins contacting sleeves. Crank reground? did they get journals true to center line? If not the rods get really side stressed. Just a few thoughts. |
Posted By: Chalmersbob
Date Posted: 02 Apr 2010 at 8:43pm
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If the cracks are at the top of the block, they will not hurt or cause any problems.
About 80% of the blocks are cracked between the web at the top. It can't distort the sleeves and will seal when the head gasket is installed.Bob
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Posted By: Dick L
Date Posted: 02 Apr 2010 at 11:56pm
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Nope, You didn't find your problem due to cracks. No way crack could cause it. If the sleeves are not out of round after they have been removed then the only thing that could cause that would be to drive them down into and out of round hole at the bottom. As I have stated many times and in this thread that the sleeve need to be able to be placed in the block and turned 360 degrees by hand. Fitting sleeves new or old in a used block takes time and care. The extra time taken to the little details will save much heartache as well as time from do overs. I use an air die grinder but an electric drill will work as well. I use a sanding flapper and keep checking the fit as I work. I use wire wheels to remove the scale also.   |
Posted By: Dick L
Date Posted: 03 Apr 2010 at 12:52pm
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Just for food for thought and maybe for conversation I looked up some stuff on piston cylinder wall clearance for Porsche and found this. [I just had my 95 bored to 98 and the spec sheet shows .0015 for the J&E pistons, so the cylinders are that much larger than the pistons, not .003, is that what your looking for?] One piston manufacture called for a clearance of .0008 in a Porsche engine. Yes a little less than one thousands. I had a machinery salesman in several years ago that quoted the clearances that was used in nascar. I can not remember what he quoted and have not found it yet on the internet. He has sold the CNC machines that were used to machine fit the heads to each already installed piston. |
Posted By: mlpankey
Date Posted: 03 Apr 2010 at 4:54pm
------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: steve(ill)
Date Posted: 03 Apr 2010 at 10:46pm
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a rule of thumb use to be .001 inch clearance per inch of bore diameter... maybe not exact, but thats a pretty good place to start. ------------- Like them all, but love the "B"s. |
Posted By: mlpankey
Date Posted: 03 Apr 2010 at 10:51pm
------------- people if they don't already know it you can't tell them. quote yogi berra |