Blowsion Cylinder Head Dome

Each cylinder head dome includes a dome locking system that prevents it from spinning when servicing spark plugs. Not all cylinders are the same and compression may vary. NOTE: All Cylinder Head Domes Are Sold Individually. 82mm domes (701) intended for use with 81.00mm to 83.50mm piston size. 85mm domes (760) intended for use with 84.00mm to 85.50mm piston size. 89mm domes (850) intended for use with 89.00mm to 90.00mm piston size. 701cc Compression Chart 82mm Chamber 701 (61X) No Porting @ Sea Level (NOTE: Stock 701 Cylinder is 81.00mm) 29cc = 230psi* 31cc = 210psi* 33cc = 195psi* 35cc = 185psi* 37cc = 170psi 39cc = 160psi * = must use 100+ octane fuel 760cc Compression Chart 85mm Chamber 760 No Porting @ Sea Level (NOTE: Stock 760 Cylinder is 84.00mm) 32cc = 225psi* 34cc = 215psi* 36cc = 195psi* 38cc = 185psi* 40cc = 170psi NOTE: These are estimations only. Many factors could change actual compression (port timing, squish, deck height and piston selection).