2.3L Duratec head swap

[boss351]

I am switching the stock head off my 2.0L Duratec to a 2.3L head (Ford Racing) and installing Crower Stage 2 cams. Does anyone know how much head surface should be shaved off to raise the compression ration to about 10.6/10.7?

[mic]

The heads are the same, you will need to measure the combustion chamber volume if it has been modified. Standard volume is around 42cc. C/ratio depend upon which pistons you are using, the piston deck height etc.

[boss351]

The block/pistons are totally stock. I know what the bore/stroke are but I don't know what volume is left when the piston is at top dead center between the piston top and the head surface. Can anyone help? (2.0L head still on the car and will be for a while-at least while the new head is being worked on).

[mic]

Head gasket is 2.7cc, the top of the piston(with flat tops)will be 3cc assuming the piston is 0.5mm below the top of the block at TDC. You should really measure this.

[boss351]

Mic,
can you check my calcs.. I pulled the bore and stroke from the internet at 8.75cm and 8.31. The bore confirms your calc for the volume of 3cc in the top of the bore with the piston at TDC assuming 0.5mm gap. Using those number I came up with a CR of 10.474:1 based on piston stroke volume : (chamber+gasket+3cc). Does that sound right? I thought the engines come with 10.2 C/R.
Appreciate your help.

Adam

[mic]

Hi Adam, it depends what engine you have, a 2.0ltr with standard flat top pistons will be around 11.1:1.

Swept volume divided by, (combustion chamber +head gasket +deck clearance) +1 = CR

Edited by mic on Saturday 30th October 21:45