Anyone have experience running a quench tighter than .040? The reason I ask is that my JE flat top pistons/Eagle H beam/scat crank/AFR210 with 68cc chambers 383 has a piston to deck height ranging from .008 to .011. I have the GM .028 head gaskets and would like to use them, only if I won’t have any problems with running .036-.039 quench.

I think my only other option is to run the .039 head gasket but then I am going into the .050 quench height.

What to do?

your cam will have an impact on this....

I`d say you`re good to go with the GM .028 gasket. I wouldn`t hesitate to use them for one second.
And the cam won`t have anything to do with it, so don`t worry about that.

My new 540 has a .038" quench. Pistons are .008 in the hole and I'm using a .030" Cometic MLS gasket. Ran fine on the dyno. Steel rods. I measured every piston with an indicator and magnetic deck bridge to arrive at the largest measurement (furthest down in the hole).

.035" to .045" and you are go to go, imho..

pdq67

I'm at .028 on my 540. Yes they just barely kiss the heads and leave little shiny polished spots. But it runs good!

JIM

We ran .028 for years. You could read .030 in the carbon on the head deck but no problems.

I`d say you`re good to go with the GM .028 gasket. I wouldn`t hesitate to use them for one second.
And the cam won`t have anything to do with it, so don`t worry about that.


Maybe I'm confused, but how does cam timing have nothing to do with piston to valve clearance? I guess I don't see how anyone can just say with a doubt he will be fine. He should check it.

Does it matter how much clearance is in the crank bearings. I am building a SJ 327 right now and am trying to figure quench.Was listening to a couple books recommend .030 clearance for SJ cranks

Maybe I'm confused, but how does cam timing have nothing to do with piston to valve clearance? I guess I don't see how anyone can just say with a doubt he will be fine. He should check it.


No, I think you have a valid concern about the p to v clearance needing to be checked. But what you didn’t know is that I am going from .575 lift on both lobes to .525 and .543 respectively. The engine used to see more strip than street. Now I want to drive the thing.

Thanks for all of the replies, now I’ll be able to relax as I get into the accelerator.

Maybe I'm confused, but how does cam timing have nothing to do with piston to valve clearance? I guess I don't see how anyone can just say with a doubt he will be fine. He should check it.

=
Probably because p/v clearance & quench clearance are two entirely different things :D

From the research I did when building, most agree as .035 to be safe and a little tighter to be o.k. even though it may leave shiny spots on the heads.