Okay Im preparing to check the valve to piston
clearance on my new Lloyd Elliot heads and CC 236/242
110lsa cam.

Since I have the heads off I plan on using the clay
method to measure. However my question is in regards
to the head gasket. From my understanding I am suppose
to use the old head gasket which is .049 compressed.
The impala head gaskets that I will run is .029
compressed. So do I just just subtract .020 to the
thinnest measurement of clay?

Im using these references as guides.

http://www.centuryperformance.com/piston2valve.asp
http://www.diyporting.com/PVC.html
http://www.marphis.com/p-v_clearance.htm
http://teamslow.aitchison.org/viewto...5ee29f868eab28

Also does anyone know if the OEM lifter internals be
inverted to mimic a solid lifter for this test? Also
is there anything I'm leaving out?

-B

 

The LT1 in stock form is a non-interferance engine, also the stock piston valve releifs are quite big. While the clay method is great, I came up with a different idea. Replace one exhaust and one intake spring with light mock up springs. Assemble the heads and valvetrain. Run the valve to full lift with a dial indicator on it. Now push the valve down until it hits the piston (or the retainer bottoms agianst the stem seal) and read the travel on the dial indicator.

Unless you've decked the block a lot or have pistons with small reliefs, you'll be OK.

 

measure and subtract .02

also measure more than 1 cylinder to be sure

 

The checking-spring method is a good one for checking a hyd-lifter setup.

Pay attention to the radial clearance too. That's the clearance between the perimeter of the valve and the piston relief. Need a bit of clay for that check.

-Mindgame

 

I just took measurement with the rockers adjusted to ZERO lash. I came up with .234 on the exhaust side...and the intake valve had WAY more.

So if I subtract the difference between the stock gasket and impala gasket which is .020 I come up with .214 in clearance.

So now my question is how in the hell did my exhaust valves smack the pistons? I know I once adjusted the rockers to 1/2 past zero lash with comp "R" lifters and 7/16ths studs. Did that cause the valves to smack?

-B