What's the largest bore you can do on a sleeved H-series? I was hoping to re do my engine to go forced induction. The current bore is 89mm, the sleeves are "LA" sleeves. Can I bore it out to 89.25 and not have issues?

 

Yes, but that will be a tough piston to find. If you intend to boost this engine, you should probably go smaller. Bores that big leave limited gasket material between cylinders and thus, the chances of blown head gaskets are more common.

 

87mm for boost and 90mm N/A??