Friends,

please apologize if this has been discussed before, but I couldn't find anything.
Will a n/a 4.0 V8 cylinder head fit a s/c engine or are they different?
Is there a difference between AJ26 and AJ27 engines head-wise?

Thanks in advance
Stefan

 

The bare heads are the same, valvegear & camshafts different, there is an old thread around three years ago on this forum called something like AJ27 swap to AJ26 which showed as I remember a guy making one engine out of two, post an overheating experience.

 

The RIGHT (bank 1) cylinder head on the AJ26 will NOT have a CMPS hole at the back of the head.

The SC engine will NOT have VVT so the oil gallery hole will need to be PLUGGED.

There was info on the plug for the early engines in TSB 303-31 but the oil supply to the VVT is not needed for the SC engine.

bob gauff

 

Many thanks both of you, this is very helpful.
I thought I might need a replacement cylinder head, but I'll write a new thread about this!

Best
Stefan

 

Any details on where the oil gallery hole is that needs to be PLUGGED ?
Thank you,
Mike

 

Did you actually look at the TSB I posted???

All the info is in that document.

If you use a S/C head the hole needs to be opened (drilled?) for the oil passage to the VVT actuator. If the head is from a NA engine it needs to be 'PLUGGED'.

bob gauff

 

If I understand correctly,
It looks like all I need to repair my 2001 4.0 S/C XKR with the dropped intake valve seat, is a good used head from a 1999 through 2003 4.0 N/A. (being careful to plug the Oil supply hole on the XJ8 or XK8 cylinder head)
Much appreciated,
Mike

 

Any 4.0 cylinder head from AJ27 engine will work.
Make sure that the intake cam is a (4) reluctor type.

AJ26 has (1) reluctor lobe.
AJ28 has (5) reluctor lobe.

bob gauff