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Mark D. 
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Joined: 14 Sep 2009
Location: Ubly, MI
Points: 215
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 Topic: flo question for the301 Dr.Allis please
Posted: 12 Jul 2019 at 1:16pm |
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Having a bit of a debate. 301cui, 2 chargers,3500 rpm limit.roller cam,stock rockers, water injection, P-pump, dry block and head. We had been running the 426 valves with head opened up as much as reputable head guy was comfortable with. Along with decompressed pistons. Question is, do we stick 426 valves in the head for flow or do we go back to running stock 301 valves? Have had a heat issue and might have to start over again. Have a lot of cracks throughout the head right now. What do you think?
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Miss Behavin - D21 Super Farm
Xcessive Tinkering - 190 XT Hot Farm Puller
Watch on YouTube - http://www.youtube.com/watch?v=J2TX1Af7aoA
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DrAllis
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Joined: 12 Sep 2009
Points: 20528
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Posted: 12 Jul 2019 at 1:27pm |
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I have heard arguments for years about oversized valves and notching the sleeves cause the air flow to be shrouded. We've always ran without exhaust seats because they usually fall out of the head at some point anyway, so just run bigger exhaust valves solves that issue. The intake shrouding thing is still debatable, but I've never felt we went backwards when running twins and notching the sleeves for the valves to clear.... Dyno test or not, if you aren't having to shift down a gear, you must not be hurting the engines performance.
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Mark D.
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Joined: 14 Sep 2009
Location: Ubly, MI
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Posted: 12 Jul 2019 at 4:34pm |
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Let me pick your brain a little more if you don't mind. We have a dog of a time starting our tractor, which we have decompressed pistons. We took a stock piston and did the poor mans test for cc's and then did the same with our decompressed pistons. Stock piston allowed 37-38cc of fluid. Our piston we have in our tractor now with the nipple in the middle ground out and valve clearance in piston hold roughly 70-80cc. Do you feel we are decompressed to far? How would you go about correcting that? Thanks in advance.
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Miss Behavin - D21 Super Farm
Xcessive Tinkering - 190 XT Hot Farm Puller
Watch on YouTube - http://www.youtube.com/watch?v=J2TX1Af7aoA
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DrAllis
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Posted: 12 Jul 2019 at 6:22pm |
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Depends on what piston you started with. A 180-190XT was called 16 to 1 ratio. A model 200-7020 was called 15 to 1 ratio. Any old 6060-6080 (not 6070) or K2-F2 combine was called 14 to 1 ratio. Using the numbers you gave me, I think you are terribly low, like 9.0 to 1. I base this off of a 16 to 1 piston. I don't think we ever modify an OEM 15 to 1 bowl at all. We just cut a straight across valve relief(s) .100" deep and leave the point in the Mexican hat. I think most dyno operators will tell you around 14 to 1 seems to yield the most HP most of the time. You need to make a compression tester adapter from a junk injector tip and body and actually run a test to see what you have. This tool is also helpful when you have engine problems and you're questioning compression numbers. Anything other than John Deere ether is a waste of time.
I knew a puller 40 years ago who used to shave off (he said) .250" off the tops of all his pistons. Never did anything else. He used a ton of ether too.
Edited by DrAllis - 12 Jul 2019 at 6:26pm
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Acllss puller
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Joined: 02 Oct 2013
Location: Ny
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Posted: 12 Jul 2019 at 8:16pm |
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So I ran an allis intercooller off. 426 on my 301 Twins , so I put an ether injector director in center port , huge difference to start , if your club doesn’t allow just remove can after warmed up good . Was so much easier to start ! Also I drilled am tapped adapter plate and used enderle injectors directly into ports to fine tune water to ports really evened out temps . We were pushing water through AC cooler at 60 gallons per min bilge pump using 40 lbs of ice and 15 gal wAter some ice left after each run , and up to 3 1/2 quarts water ink to
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Carl(NWWI)
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Joined: 13 Sep 2009
Location: NW WI
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Posted: 12 Jul 2019 at 11:26pm |
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Had some head work done with my 301 head. If I remember correctly the stock valves and head flowed 120-130 cfm. With some porting work done, a 426 valve, opening up the bowls, and either a 3 angle cut seat or a 45*, don’t remember which, but it flowed 180cfm after that. Notched the sleeves and it was a night and day difference of performance.
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Relayman
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Posted: 14 Jul 2019 at 9:40pm |
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I have often wondered if these flow tests that show a large increase in flow with valves that require notching the sleeves are flow tested with the notched sleeves in place or are flow tested into open air.
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Carl(NWWI)
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Posted: 15 Jul 2019 at 10:41pm |
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You can’t flow test a head on that tractor. So it’s without the sleeves.
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rowcropmafia
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Location: illinois
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Posted: 16 Jul 2019 at 10:58am |
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You always flow test on a bore of the proper size. If they tested it on the right bore with notched sleeves your results should be accurate. The flow numbers aren't really what's important. It's the results at the pull that counts
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