im having a possible issue with valve to piston clearance... i dont have a caliper at hand,

i have AFR 195cc heads with 2.05/1.60 valves, and was going to install them on a .030 over stock style piston short block(stock style cast aluminum pistons) block has not been decked either
my cam is a mild turbo grind, only 444/447" lift, but the area of question seems to be in the width of the valves compared to the width of the valve reliefs in the pistons....

if anyone's had experience with this big of a valve on stock pistons please help me...

thanks!!

 

well with that much lift i think you will be ok. What gasket will you be using

For reference i have flat top pistons with tiny valve reliefs on a decked block using those heads. .040" gasket. Cam is pretty mean at 230/245 duration and .603/.613 and i have plenty of clearance. Around .120 on the exhaust side, well over that on the intake.

Valves shouldnt come that close to the valve reliefs

 

i am using felpro multi layer steel gaskets, i do not know off the top of my head what thickness they are....

 

i believe they are .040"

 

The "correct way" would be to get a kit to degree the cam. Replace the valve springs with checking springs on one cylinder. Set the valve lash to 0. Install the degree wheel on the crank and follow the instructions to align the pointer with TDC. Setup a dial indicator on top of the valve retainer (parallel with the valve stem). As you rotate the motor near the potenial interference points, push down on the valve until it hits the piston and read the clearance off of the dial indicator.

The intake valve will try and hit the piston when it first opens.

The exhaust valve will try to avoid hitting the piston as it closes.

I would check the clearance in 2 degree increments in these spots.

 

thank you verry much, i was looking for a quick "yay" or "nay" but after thinking about the cost of replacing the heads i think i will take my time and do it that way this winter.... just get the car running with some stock iropn heaeds for now.....


and the turbonertics TC78......

thanks again.
keith