phughes69

Does anybody run their 2nd ring gap smaller than the top ring. I'm trying to figure out if this is a good idea. My old rings had a top gap of .031 and the 2nd was .030. The motor is a 4.250 bore 454 BBC with twin turbos

Black Baja

iTrader: (2)

I've never ran the second ring tighter. When it comes to stuff like ring gap the best thing to do is talk to the manufacturer and see what they suggest. Tell them in detail what the motor is. How it will be ran temperatures. Water pump no water pump. Proper gap and wall finish can make or break a motor as far as making power.

Unlimited jd

iTrader: (5)

All of your rings were .030 and .031? That's pretty good for ring gaps, pretty lucky if cylinder to cylinder is within .003

snapmorgan

iTrader: (2)

There will be a sheet with the rings to yell you where to gap them depending on application

14 apache

iTrader: (1)

This was old school thinking. The rings work better with the second gap bigger.

Budman II

iTrader: (1)

I'm running Mahle forged flat tops in mine - the techs with Mahle recommended .022 top and .024 2nd if I recall correctly. He told me that they were running the second gap larger nowadays to reduce ring flutter. .030 sounds like a pretty big gap, but that may be due the the use of a power adder. I think you want to run bigger rather than smaller gaps on a marine build anyway. Do some homework on this - you definitely don't want to bust a ring or ringland, but you also don't want to end up with a ton of blowby and excessive oil consumption.

Black Baja

iTrader: (2)

Especially when you are really stuffing the motor. An xtra .010 o the second ring can be worth considerable horsepower.

airjunky

iTrader: (2)

I think the mahle guys are anticipating some "trapped pressure " between 1and 2 to provide some ring seal and oil control on this one also. Lots of tedious measuring for you it sounds like.
It will all be worth it when you fire that thing off and flog it for years to come.