Hello, I was hoping someone can point me in the direction in how to verify an XK140 has a 3.5 litre engine instead of the standard 3.4L. I understand they are uncommon, and I see one raced in the 1956 LeMans finished 17th. I would like to be able to verify a 1956 XK140MC DHC that claims to have a 3.5L engine does in fact have one.

Submitted by allen.williams… on Wed, 05/18/2011 - 19:15

Thanks George and Otto.

George, you were spot on with directions for finding the markings. I found the cast marking as "3 1/2 Litre" and the engine no. above the oil filter matches the head number and those match the mounted plaque.

One last question, have you seen a factory installed floor mounted automatic transmission on a XK140? All the factory installed automatics that i have seen are column mounted Borg Warner's.

Submitted by SE98-32482CJ on Wed, 05/18/2011 - 14:03

Allen --one more point--while you are "sleuthing" use the flashlight (torch in English) and have a rag. Wipe down the area directly above the oil filter housing and record the engine number. If it is from an XK140 it should be GXXXX-X. Also check the head matches the engine block. Head number is on the rear edge of the front of the head valley (where the sparks are). Good luck and let us know please.

Submitted by SE98-32482CJ on Wed, 05/18/2011 - 06:18

Allen Jaguar marked their Engines for marketing and-and Tax reasons in Europe. The 3.4 L engine was actually a 3442cc. The Engines casting sometimes said 3.5L and 3.4 L and 3 1/2 L. There is a history of all of that but for your question I think you are reading something that has you misled. The 140 that raced at Le Mans was a stock 140 with a bit of special prep. If I remember correctly it was not new but had about 20.000 miles on it already.