I need to replace the 9:1 head on my '60
MKII 3.8

A major Jag rebuilder advised compression ratio determined by the pistons I.e the 'hemi' effect so that an 8:1 replacement head would result in no loss of HP

Are the cams the same, that is the 8:1 cams would have same lift and duration lobes--- is this accurate ?

Thanks

Submitted by NE08-63766 on Fri, 05/17/2013 - 02:28

Hi Curt,
Yes, the pistons determine the compression ratio. The MK-II, 3.8L engine has originally fitted 8:1 comp. pistons. The head # should start with the letters, LA, LB, LC, or LD-xxxx. How do you know there are 9:1 comp. pistons fitted? The head is your standard "B" type head, cam lift of 3/8", 1 3/4" intake valve, 1 5/8" exh. valve, (2) SU HD-6 carbs. & all that will give you 220HP.
The part # for the 9:1 pistons are C-16339/2.

P.S. I finally was able to download that light sw. photo.

Regards, Otto