honda9krpm

The scratches are not very deep. However I like to repair the engine properly and to be able to handle a little bit more boost. It will be an expensive bill but I dont like any short cut and it's unfair for the next owner if I just rehone it.

chris_barry

Enlarging the bore 0.25mm to suit oversided pistons is standard engine reconditioning practice. It is much cheaper than sleeving, especially if you only have to do one cylinder ( make sure you balance all the pistons together).

You could actually get a set of +.25 sized low compression pistons so you can reduce the compression and recover the bores at the same time.

With forced induction I would suggest slightly more bore clearance to allow for more piston expansion as they will run hotter than designed.

Speedracer.