My running 63 Mk2 3.8 has a W head (red paint remnants) which points me to a XK140 3.4 head for a S block. The 3.8 block is a 3.8 B and matches the installed engine number. Without removing the head to inspect, does anyone know if this head was considered a marginal replacement for a true B head? As previously mentioned, the car is running and has been running since purchase with the W head.

Submitted by Charles@thebre… on Tue, 08/14/2012 - 10:43

Hi Phillip,

When you have the opportunity, please send the details of the head to me, off forum, at charlesatthebrennanclan.net

Thanks,
Charles

Submitted by NE48-24099 on Tue, 08/14/2012 - 09:00

yes Charles, that confirms what I had previously thaught.
Your head is from an early XK120. Your block is a correct MkII 3.8.
As a point of info, the head I have is LC1417-8
Regards

Submitted by Charles@thebre… on Tue, 08/14/2012 - 08:15

I had my wife check the serial numbers. I only had her get the ones that were easy to see and I know the block is the original (number matches).

ID Plate: LC2606-8
Head: W8941-8S

Submitted by NE48-24099 on Mon, 08/13/2012 - 07:58

That's fine. What is the serial # stamped on the head? And the serial # on block? And the engine # on the brass ID plate?

Submitted by Charles@thebre… on Mon, 08/13/2012 - 07:29

Hi Phillip,

Thank you for the details on the difference. I am not quite at the point, in the restoration, to replace the head, but it will be done based on your information. I would be very interested in the spare B head for the 3.8.

Thanks,
Charles

Submitted by NE48-24099 on Sun, 08/12/2012 - 23:37

Charles, the "W" head would be from an early XK120. This would be known as a 'A1', with 5/16" cam lift, and 1 1/2" exhaust valves. Later XK120 had serial #'s with an "F", and XK140 had a "G" . All of these would be a 3.4L. Your MkII would have LA, LB, LC, and would be a "B" head, with a cam lift increased to 3/8", and exhaust valves increased to 1 3/4". I have a spare 3.8 "B" head from a 62/63 MkII if you are interested.