Rethinking Peel's Ring Pack

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Rethinking Peel's Ring Pack.
Manual lists Standard top 2 ring gaps in standard engine run at standard rates as .012". When Wes and me start smoking to point we can't take it we find gaps of .022-024" but also the sharp corners rounded off. So which causes the smoke the edge seal loss or bigger gap? Gapless rings might only help in lower rpm so some say no advantage after some rpm rise yet they sell a lot of em for everything. The heat must be factored in with the diameter of the bore. What's it all mean to Peel? .021" top & .026" 2nd or none at'all? Too much variable vitals to quote so dig in before advising please factoring in forged type piston in alloy cylinder cast iron sleeved and never a vacuum seen in chamber. Peel ring blow by will be actively sucked out. Do note almost no one is posting on boosted air cooled antiques for good reasons, except our dumb ole Harley cousins. Oh yeah certainly none with Peel's tapered bores either.

http://www.totalseal.com/Techpage.aspx
http://www.enginebuildermag.com/2011/02 ... orsepower/
http://www.dailymotion.com/video/x6xma5 ... e-new_auto
http://www.aircooledtech.com/piston_rings/
http://www.thumpertalk.com/topic/987628 ... different/

There is a lot of debate it seems on a boosted combo, I set mine at .035 top and bottom on my 4.155 bore SBC. Ring butt is not a good thing!

He builds the baddest turbo engines out there, I am sure there are some things that are proprietary...like his piston desig

Well, no specifics but I would say it is best to err on the side of strength. And plenty of ring gap. I've seen motors with gaps you could drive a volkswagon through that still had excellent ring seal. Excellent machine work is far more important


The tighter clearances will NOT work for high hp turbo cars. Too much heat will cause the pistons to expand too much and contact the cylinder walls. Not good. For turbo run AT LEAST .004" to be safe. You won't see any piston slap until over .005" (not noticeable anyway.)

Top ring gap: .017" moderate turbo/nitrous .015" NA. Race .019"
Second ring gap: .019" FI, .017" NA, .021" Race.

I think on the next motor I am building currently I am going to go for a tight ring gap. Even at .014" I don't think anyone would experience ring butting issues. I will either go with .017"-.019" or .016"-.018".

but measuring the gaps needs to happen at several spots in the bore. A lot of guys recommend measuring at the top of the bore about .5" from the top where the ring sits at TDC and doing the gap-fitting there. It makes sense though, that is where the piston rings get hottest. Just as long as the machine work doesn't have a lot of taper in the bore. The smallest variance in taper will cause the ring gap to increase in relation to pi. so .001" in taper would mean you would possibly need to alter the gap by .0031". This is why it is so important to fit rings for the bore they are going to be used in.

yes. On a larger bore you will need slightly larger gaps. 86.5mm you could still get by on the 17 and 19. Any larger than 87mm and you prob would wanna go 18 and 20.

The 4b11 guys also run a .017" gap on most boosted engines that are built. But for 2nd gap and modified street boost they see .023"-.024". I wouldn't worry about .020". Its perfect, throw em in!
 
With your JE pistons and rings, you might consider going with JE's recommendations. For street turbo or mild nitrous, they recommend .0050" per inch of bore for the top ring and .0055" per inch of bore for the second ring. Those are minimums. With your 81 mm bore, that comes out to .016" top and .018" second ring. Gap for all the oil rings is .015" minimum. If you need a little margin, go with .017"/.019", or even .018"/.020" because its air cooled. In the world of boosted engines, yours is actually pretty mild, so I don't think you need to go to the extremes on end gap that blown nitrous dragsters use.

If you're using the totalseal rings (I don't remember which ones are in the box, and too late tonight to go check), I'd check their recommendations, but I don't think they're going to be much different.

Just my 2 cents worth of input.

Ken
 
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