Piston to Valve Clearance

[Mopar451]

has anyone ran piston to valve clearance on the exh. .080 ths. and it worked, im thimking I need to cut the exh. pocket a little but just wanted to see if someone has tried it.
Thanks

 

[rumblefish360]

I've run it where the valve allowed no carbon on the slug. This was engine break in on a ill degreed cam. RPM was low.

 

[twayne24365]

Old 383 out of dads car had .094 exhaust valve clearance and we ran it hard.

 

[IQ52]

It depends upon the engine design and condition. Our 451 had .065" clearance on the exhaust valve. Solid roller 278/280 @ .050, .800/.800 lift @ 1.6, 275# at installed height and 780# over the nose @ 7,600 rpm. No problem.

 

[TrailBeast]

.080 is about 3/4 of 1/8 inch if thinking about it that way helps you feel better.

 

[AJ/FormS]

Or about double a headgasket thickness
Or 3 to 4 times the lifter preload.

 

[twayne24365]

Not to hijack but I'm bringing this thread back, I finally got my heads back from the shop and mocked everything up, looks like with my head gasket I'll be a little tighter, .075 on the exhaust. Put it together or get thicker head gasket?