I am working on a car that has GTP Stage 2 heads that are cut 0.03" with a stock bottom end. The cam that we are trying to get in is a TR230/224. The specs on that cam are 230/224 @0.050 with 0.575/0.563 lift. We installed the heads and puttied the piston, the valve went through the putty and contacted the piston. We now have the Isky flycutter tool for this weekend and I was wondering what is the most amount of piston material that can be removed, what is the margin of safety for P/V clearence, and if anybody has done this what is a good amount to start cutting (like 0.035 or 0.04).

Thanks

 

.060 intake, I doubt exhaust needs any with that cam, but since you're doing it anyways, cut on exhaust as well.

 

.070-.080 is a good starting point.

 

These heads were on another car with the TR224/224 with out being cut, but I was planning on doing the exhaust as well.

 

Should go ahead and cut, I agree. If you don't, you might have to set your rev limiter too low so you have a margin of safety for mechanical over-rev.

 

hijack...

how do you measure the depth of your cut into the piston?? what tool do you use?
Erik

 

I have been using feeler gauges at the stop collar and the eyebrow.

What is the max safe amount that can be taken out of a stock piston?

 

i want to know all of this as well
Erik

 

I have heard of people taking 0.1" out, but I dont know if that is a myth or safe?

 

I wouldn't take out more that necessary to keep .080 clearance. Feeler gauge is the correct way. Make sure and smooth out the sharp edges left.

 

When you clayed, did you have checker springs in there? If you did, then you had no lifter preload accounted for, since the checker springs cant depress the lifter plunger. I could see that cam cutting it close, but actually hitting seems a bit suspicious to me.