Brought this one up before, and never really got an answer as the thread went sideways.

I finally got out into the garage to start work on the 454's assembly. Right now, I'm measuring ring end gaps and wondering where I should be aiming. Data on this is all over the place, both here and out on the www hence bringing it up.

Current measurement shows .025 end gaps for both the top and second rings across the board. This works out to .0059 per inch of bore (based on 4.251 bore after honing).

I was thinking of taking the top ring to .028 and the second ring to .030 (.0065 and .0070 per inch respectively) to handle the blower. I've seen some discussions saying run less, others say run more. Pistons are factory 4.25 GM/TRW for which there aren't any published guidelines to reference.

What's the general consensus? Thanks!

it depends on the rings.when you buy rings they come with gap recomendation.

The instructions for the rings say to follow a minimum of .004 per inch of bore diameter.....

you are 50% above their min of .017 then. they know how much their rings expand with heat.

Tom,

What ring pack are you using? Are you employing a napier second ring?

Water temps?

Bob

Bob,

They're a Hastings 2M683 moly ring set. 5/64, 5/64, 3/16. Nothing exotic, but a good set of tried and true moly rings. I believe some may balk at the ring set used, but according to Hastings, these are supposed to be the same rings in use by Wiseco.

Water temps... I will not be running a thermostat (but will run a restrictor plate), and I boat in 70-80 degree water typically. Maybe a touch higher. Mid Atlantic... Chesapeake, ICW, five miles offshore.

Wiseco is where I got my gap figures from, but I just wanted to be absolutely sure that I'm on the right path. I could put another call into Hastings today, but bringing it up here helps to educate more people on the subject.

Thanks!

Tom, I think you'll find the water restrictor to do nothing for temps and just raise the psi in the block .

Just run it wide open then?

Adding... I did this on my small block set up, and it got my oil and water temps into a good range. Wide open it would never really warm up.

I highly recommend an oil thermostat if you don't have one. I've tried the water restrictor plates when I had the 250 blowers. They really didn't do anything except raise my water pressure too high

Got it Joe. Thanks! The oil thermostat set up is on my shopping list.