I know someone who shaves the heads on their car engines to get a little higher compression ratio.. one of those cars happens to be exactly what I drive and I can tell a moderate difference in the "peppiness" of his engine over mine. I have a spare vf500f engine laying around and I was thinking about having him shave the heads on it just to see what happens! Does anyone have any thoughts on this?!? It is just for fun since it is a spare engine
The immediate considerations are valve-to-piston clearance and cam timing. If the cams are gear driven, the gear lash may be an issue, as in the gears will now be too close to one another, unless there is an adjustable interim gear that lives between the cam gear and another driven gear. If it is a chain drive cam, the cam timing will be retarded to some degree, which can be beneficial at higher RPM, but will hurt the lower RPM performance in general. If the cam gears are adjustable, you can correct for it. There is also the cam chain tensioner to consider. In effect, the camshaft drive chain is now longer, since your crankshaft centerline to camshaft centerline is now closer. The above will be mechanically affected, although perhaps not to a huge degree. I mention them just because they may be an issue. From a performance gain compared to the pain-in-the-ass factor, it might make more sense to go for oversize pistons, as that will raise your compression ratio and increase your displacement without having to monkey around with the other issues. I don't know the VFR engines; this is all just general considerations.
