I need some help installing my 10.75:1 stock bore piston in my 03 raptor. I just put in a stage 1 hotcam. I have adjusted the valve lash per hotcam specs, but i am worried that the increased lift will cause the cylider to hit the valves. What exactly needs to be done besides replacing the piston, rings, and gaskets??? do i have to use clay to check the poston/valve clearance? do i need to hone out the cylider or anything, if so, how much? any help would be great, thanks.

 

Anyone?

 

I measure everything!!! Clay or the tip below.

I'll give you some tips. If you have it assembled already, you can take a piece of solder and stick it through the plug hole under each valve and turn it over by hand. A flashlight helps here. Take it out and measure. If you don't have it assembled, you can do the clay deal if you want. Both work great.

Yes, if you put in new rings, hone it. Just break the glaze on the cylinder, and measure for roundness and clearance.

Good luck and have fun with your modded Rappy.

 

In the past the set up you have does have enough clearance. (Valve to piston) But the Doctor is right clay everything or measure it somehow.

 

With a 10:75:1 and if you're timed right you will not have a problem. It won't be nessessary to go through all it takes to measure piston to valve clearance. You should have miced the cylinder and pistonto get proper piston to cylinder wall clearance for sure. At the very least hone the cylinder to break the glaze as stated.