piston to head clearance [Archive] - Chevelle Tech

: piston to head clearance

Jan 16th, 08, 2:49 PM
i have 396 .30 over l2287 closed pistons and 115cc aluminum open chamber heads, no decking .039 gasket. will domes clear the chambers? the motor is together but not fired. do i need to use a cam button with a thumpr roller cam if i use a front bearing? people have brought up these issues to me. any help would be great
thanks brian

Tom Mobley
Jan 16th, 08, 4:58 PM
if it turns over with the heads bolted down it's probably ok.

you need a cam thrust button properly installed to keep the cam from moving forward in the block. this is required on retro-fit roller cams. this is not optional.

Is that one of the CC cast iron roller cams?

Jan 16th, 08, 5:09 PM
its a comp cam mutha thumpr hydraulic roller i dont know if it cast iron or billet

Jan 16th, 08, 6:39 PM
I guess since it's already together it's too late to check. But my 2287 pistons in a 781 casting open chamber head hit the sides of the chamber. But I do all my clearance checks without a gasket. That way I know if it clears without the gasket, it'll be fine with the gasket.

Jan 16th, 08, 7:13 PM
i turned the motor a full turn. it turned freely, the valves are not set though. it wouldnt turn if pistons were hitting side of chamber, right?