Z Tech Tips 2mm Shave N47
The idea is to turn a common N47head N42block combo into a higher compression motor by simply shaving 2mm off the head.
The cc of the shaved head is measured below. It is 32cc. The stock is 44.6cc so 12.6 cc's are trimmed.
By using a Felpro 0.7mm head gasket, the stock compression of 8.29:1 jumps to 10.40:1
Old CD lid (with two holes drilled) and some wheel bearing grease seal the chamber for measuring volume.
Note the spark plug is in place.
40cc initial volume
Inject and bleed air
8cc remain so chamber volume = 40cc-8cc = 32cc