Boodyrider

iTrader: (2)

Some of you know I'm going with the Comp Cams XFI cam, the 230/236 @.050 and .576/.571 gross lift (with 1.6 rockers).

I decided to raise compression a little bit with the Impala head gasket (.026 thick instead of .039 like the aluminum headed LT1 version).

Short block is stock, with the 'eyebrow' valve reliefs, and the heads are surfaced no more than 0.010. Probably more like .005 as a cleanup. (Of course, Jasper did get hold of the heads once, many miles ago...)

Anyone think I'll run into piston-to valve clearance issues? If so, anyone want to explain just how to clay the pistons, preferably in a way I won't have to buy yet another set of head gaskets after the process, since the heads are torqued down now?

Thanks for your input!

sssalah

I don't think you'll have PTV interferance, but it's best to check rather than hope. If you're going to use the clay method then the head must be removed. You can use a checking spring to measure the actual clearance between rocker arm and valve stem tip when the valve is pressed manually to touch the piston.

96capricemgr

iTrader: (1)

Gaskets are .049 stock aluminum head, .039 Felpro for aluminum, .029 stock iron head, .026 for Mr. Gasket 5716

I have yet to hear of an LT1 with PTV issues especially not on a stock shortblock.

My heads are cut .032 using a .026 gasket on a stock shortblock with a suprizingly good .022 deck height and a bit less lift than you but had no problems.

vanilla89

iTrader: (8)

you'r fine enless you have 2.05 valves or bigger

nazar

i am doin the ms gasket .026 gasket, custom cm motorsport cam (.570/.569) lift, 1.6 rockers, head decked .020 to get as much compression as possible

The motor was stock rebuilt, 355 with standard valve reliefs...my intake valve is a 2"

Should I be ok?

fergymoto

iTrader: (129)

My valves didn't clear the pistons with my setup (Mr Gasket 5716). Heads have been shaved .015 I think. Cam specs in sig. Stock short block. I had to cut a good bit into the valve reliefs.

vanilla89

iTrader: (8)

a 242/248 is a loot bigger than a 230/236.
what size valve are in the heads

94z28L

iTrader: (4)

would it be the duration of the cam that causes PTV issues tho or would it be the lift?

vanilla89

iTrader: (8)

its moor the duration and lsa ,the lift doesnt have much to do with it because the piston is down in the hole at full lift

fergymoto

iTrader: (129)

I have 2.02 and 1.60 valves.

SStrokerAce

iTrader: (2)

No you will not have problems if you degree it in correctly.

Bret