Quote:
Originally Posted by IamFODI
Here’s a minor wrinkle: Increasing the distance between the piston crown and the first ring can reduce power as well. This is because it increases the volume of the zone around the piston where the air-fuel mixture can't burn efficiently and usefully.
https://www.enginelabs.com/engine-te...le-motorsport/
https://www.enginebuildermag.com/201...r-of-a-piston/
I don't get the impression that the stock piston has a super high top ring, and I feel like I remember hearing from the guy at Mahle Motorsport that their POWERPAK pistons for this engine only lower the top ring very slightly. So, this effect is probably insignificant in this case.
It is, however, yet another illustration of the fact that every design decision by a competent OEM has at least some good reasons.
Don't think this moves the needle on any decisions I'd make – i.e., if I had to pull the trigger right now, 99% chance I'd still go with a Partee build with POWERPAKs. But I might dig into this aspect further, if only to learn more. |
i would probably say it is negligible, just like how oversized Rod Bearings / Main caps do the same thing, you probably wouldn't want to run a combination of both as oversized either. if it was me, i'd probably do oversized mains and std rod bearings.