Just though I would post this for those of you who are interested

jaguar 48 valve quad cam v12 | eBay

 

Nice... wonder what kind of power #s that would make?

 

Looks like sombody has gone fair way down the AJ6 head on V12 block. The 2.9 litre head is basically a V12 head but my oh my there us a lot of work yo make that work. Has he tired of the project or concluded that it is beyond his capabilities?

 

very nice piece of engineering, but a lot more work to make it in a usable running form.

looks like a hydroplane setup, and who knows if ALL clearences are correct.

but for $4000 AU , you could not reproduce it again.

some pix were on another site, same engine with 12 TBs.

 

from what ive read, theres a reason why Jag discontinued the DOHC V12. and that reason is that with a good cam, you can outperform those heads.

 

Jag did not persue the quad cam heads because it moved the weight higher up which had an adverse effect on handling of the race car. They do make more outright power with the sacrifice of some low to midrange. Jaguar deemed it not worthwhile for the costs involved. There are still a couple of Jaguar built quad cams around I remember reading an article this year by a guy who bought one out of Germany.

 

There were several reasons: Flathead had better low down torque and midrange was perfectly good. Had they gone racing I guess they would have persevered with the 4 cam. In addition space was tight enough in the intended recipient, the XJ6 which was under way. To top it off the twin cam would have been more expensive to produce.

 

The quad cam was developed for the le Mans sports car racers not the XJS specifically the XJ13 and is a completely different beast than the AJ6 headed one in the post.

Here is a link to some info, this guy has rebuilt one of the original Jaguar prototypes

Jaguar XJ13 | Building the Legend

 

True, the XJ13 has the first iteration which was also tested in a Mk 10 for road engone evaluation. Those engines had what is basically a XK head configuration i.e. With hemispherical combustion. chamber.