I have set of turbo pistons from an ’88 951 that I’m hoping to use in my rebuild, however one of the pistons shows signs of valve kiss. The mark is very small, about 1/2" x 1/8” and only .014” deep. The hit is small enough that I’m thinking I can still use the piston if I smooth out the ridges to avoid any hot spots. My plan is to have the piston tops swain coated.

So can this piston be salvaged, or do I need to find a new one?

 

all 4 of my pistons have that kiss mark, as sometime in the past the timing belt must have failed. I smoothed them out and re-used them without problems.

 

I was talking to an engine builder about this as we were looking at a piston (none Pcar) that was hit. He advised that you check out the top ring groove for proper clearance. He has seen the top ring bind after the valve hit the piston. I guess it is all related to how hard it hit and the type of piston.

 

could probably just sand it down real smooth and be good to go. I got some FOD on a mazda motor I had and it got a bunch of similar knicks in the piston. I was able to run 18 psi on it though.

Only thing I have heard might happen is you get a "hot spot" which could cause the piston to crack.. or some thing along those lines. Some one correct me if I am wrong though.

I think you will be fine if you sand it down nice and smooth.

 

Mine has some valve kiss marks on it, and all I did was make them smooth so there was no material sticking up. No issues with them at all. Good Luck.

 

Youre fine.

Hell ill go and bend my valves just to have those dings in the pistons. Battle scars give the car character.

 

Thanks for the info guys. I figured I could probably get away with it.