Hello all, this is Andrew from Jaguar Specialties. As many of you may know, we have been offering kits/parts for GM LSx conversions on many different Jaguar models (including XJ8's) for a while now. To give enthusiasts an idea of the possibilities, we just posted a new gallery of completed Jaguar LS conversions, all done with our kits and parts.

Most of the cars were built by customers, and a few by us.

Conversions are not for everyone, but for those looking for an alternative to the stock power train, this is a viable way to go.

What's interesting is the truck versions (iron block/alum heads) of the LS engine will fit these cars exactly like the all-aluminum car versions and are just as smooth, but are thousands of dollars cheaper. For example, 2 of the customer cars below were built with truck 4.8L drivetrains- a drivetrain package like that (engine/trans.accessories/wiring/computer) can be bought for around $1000 , in total!!! And they all respond well to the same aftermarket upgrades/bolt-ons as the all aluminum versions. Depending on the year, in stock form, the 4.8L makes 255-275 hp and 285-295 ft-lbs of torque. The difference in weight (+ 75 lbs for truck LS vs cars LS) does not seem to affect the car at all...

We can't post an actual link to the site, but here are some of the pics.

For more info, get in touch with us- send a message

99 XJ8 with 99 Chevy truck 4.8L and 4 speed auto overdrive trans



(picture of actual car below before engine was installed- that's why it's sitting high in front..)



01 XJ8 with 00 Chevy truck 4.8L and 4 speed auto overdrive trans





And this is/was out prototype- 98 XJ8 with 98 Camaro LS1 5.7L and 4 speed auto overdrive trans

 

Interesting. I'd like to see a before/after comparison of performance, mpg, etc. Do you have the numbers?

 

For the most part, conversions on these models is done primarily to get away from the high cost of running and repair of the Jag drivetrains. In that regard, once converted, the car will save the owner thousands in repair costs over the long term. The added performance is a major bonus. Even though the 4.8L LS engines put out similar power to the original 4.0 Jag v8, the torque is higher and both the torque and hp come in at lower RPM, so the car feels/drives as if it has more power. And then going to the larger 5.3L and 6.0L truck engines or the 5.7L or larger car engines, the power gains are larger and the cars are genuinely faster. I'd run my 5.7L XJ8 against any XJR and win any day. I believe GM underrates the power output on these engines (for insurance reasons) and actual output is higher than advertised.

As far as mileage, customers with the 4.8L card are reporting 25mpg on the highway going 75+; one of them thinks he can touch nearly 30 if he kept the speed down. These engines rare very miserly with fuel when driven that way.........

Thanks

Andrew
Jaguar Specialties