300ex high comp piston question

[jtej]

I just tore down my friends 300 to rebuild it, right now it has a wiseco twenty thousands over stock piston. When i tore it down i noticed that the valves are touching the piston top. They aren't actually hitting it, just touching enough to keep the carbon build-up off the piston and valves. Will this cause a problem in the long run? Has anyone had this problem?

Thanks
Jonesy

[jtej]

Bump

[JDiablo]

i think time for some new valves and seals,and springs,that is just me if anything i would call your local dealer and ask if someone isn't giving you the right answer here

[Aceman]

The valves should not be hitting the piston. Is your friend running a thin head gasket? Is the piston installed correctly and not turned 180 degrees? Were the valves adjusted properly? If they were overtightened the valves would extend farther down into the cylinder possibly hitting the piston.