Originally Posted by Fiecos Dan
Originally Posted by Cosworth Bassie
Std head unskimmed measures 139 mm.
My head is 138.6 mm and the combustion chamber measures 46 cc.
Std 4 wd Piston Dome Volume is 19 cc, and my new pistons have 24 cc Piston Dome Volume.
Hi,
Thats odd,
my 4wd head has 44.5-45cc across them @ 138.2mm,
and yours being a 2wd head has got more CC as std, but with 138.6mm its only 1-1.5cc more than mine.
i measured 2x std 4wd pistons @ 19.5cc, the ones in my engine are 20.25cc.
i want to know for reference and to know what my c/r was before and now.
You need the following specs to calculate comp ratio:
Cylinder Bore Size
Piston Stroke Length
Head Gasket Bore Diameter
Compressed Head Gasket Thickness
Combustion Chamber Volume In CCs
Piston Dome Volume (Negative For Dished Pistons)
Piston Deck Clearance (Negative If ABOVE Deck)
Regards,
Bas