Shaving Cylinder head

[TheGaginator]

looking for higher compression. How much can i shave my engine head down without interfiering with valves? also, will i have to worry about my piston strength?

[burning1]

Personally, I'd start by shaving the cylinder block before I machined the head. Stock, there's too much clearance between the piston land and the cylinder head to benefit from the squish area of the piston. Closing up that gap will gain you higher compression, but it will also help reduce detonation and increase your burn by better mixing the air in the chamber.

The racer's corner on the main site has some info on machining the block. If you do decide to have a go at the cylinder head, be aware that there may be clearance issues between the dome of the piston and the head - the GS has a fairly narrow oval shape combustion chamber, and an unusually narrow dome on the pistons.

When you deck the heads, you should probably also slot the cam sprockets, or see if you can find aftermarket adjustable sprockets... Decking the heads will change (retard, IIRC) cam timing.

I don't have an answer for you, but you could probably figure it out by claying the pistons and carefully measuring all clearances... Just be aware that valve to piston clearance will change with cam timing and lash adjustment... And aftermarket cams will dramatically change valve to piston clearance.