Is there anywhere to source the upgraded head gaskets from the 4.2 to the 4.0 XJR and all the seals for the 4.0 or would I need to buy the headgaskets separate from the rest of them?

98 XJR

 

Go to partsgeek.com and look up an 05’ XJ8, engine, head gasket, Payen left and right. Ignore the higher priced Payen vs the much lower priced Payen HG’s. Just get the $50 x 2. The 98’s had real thick valve cover gaskets so….. to answer your question , to the best of my knowledge, there is no 1998 gasket set with 4.2 mls HG’s available as a one and done complete kit. I’ve used the Payen HG’s on my own 98’ XJR and it’s been holding up for about 10 years now with no issues.

 

Sounds good thank you

 

HG came in but not for the 05 XJ8. Is it Normal to say a different car or is this a mixup?

 

ALL AJV8 4.0 liter engine blocks are the same.
The differences are mostly in the upper sumps and intake cams.

I have a 2001MY S-Type 4.0 (AJ28) engine block with AJ27 cylinder heads and upper sump in my 2000MY XJ8L.

The XL8L had a seized engine and the S-Type engine had a 'dropped valve'.
I just took the S-Type engine apart for the short block and installed good used upper sump and heads from an AJ27 'nikasil' failed engine.

I installed the MLS head gaskets from the 4.2 AJV8 parts catalogue number and used them.

The 4.2 engine has the same BORE as the 4.0, just a longer stroke.
Head gaskets will fit fine. (FORD 3.9 liter head gaskets WILL NOT FIT)

I don't know if the old composite gaskets are being made anymore?