As the name would imply… this will inevitably trigger some of you. But I own a 1989 jaguar XJS v12 Coupe with the 5spd manual. I plan on changing that. The 5.7 hemi is far cheaper to gain power, maintain, and find parts for, as I plan on road racing it. Didn’t want to go the basic 350 route, and LS options are far too expensive nowadays. I plan on doing a full swap with the 8hp70 8 speed auto to match, but don’t know how bad I’ll have to cut up the original car, as I’ve never seen this swap done before. Any thoughts or ideas? (And if you say keep the v12 someone is getting slapped)

 

Sounds like a cool and interesting project. I'd enjoy watching it develop.

That said, over the many years we've had a lot of lumpers on these pages and we've all gotten along really well. A lot of us here are happy about that and would like to keep it that way.

A couple have been cocky or belligerent or insulting. They're gone.

Pissing off purists, triggering other members, or offering them a slap in the face, is starting off on a very wrong foot around here.

A lot of us enjoy conversion projects and there's a lot of conversion knowledge here to be shared. But I can promise you that nobody here is impressed with coming off belligerent or cocky. Nobody.

Ease up.

Cheers,
V12 Purist,
DD

 

Um? I have no intention of coming off as cocky… or belligerent. Merely tired of being told what is right and wrong for MY build. I don’t care what anyone else does, and my name is merely what this project has done… All I came in search of is a little bit of potentially helpful knowledge on how to make this project a little bit easier, as to my knowledge I’ve never seen it or heard of it being done. I’m just trying to do my own thing and get some pointers, the vaguely threatening message wasn’t required. If you have info that would be beneficial, please leave it.

 

I'm not aware of anyone here doing that to you


My experience along these lines is a Triumph TR6 V8 conversion, so nothing helpful to you

However, start reading posts/threads by "iscamerica". He has tons of background with various engine conversions into Jags, does a lot of track driving, and has a lot of helpful insight on beefing-up the structure and suspension for the kind of power you'll have

Postings by Andrew at Jaguar Specialties are also very useful....although his focus is on the LS-engine swaps

Others will chime in

Cheers
DD

 

Much thanks Doug, I will look into both of those sources, and will gladly keep you and the rest of those interested updated with photos and progress results!

 

Another engine to try is one of the OHC Ford V8 offerings.

I'm going to try and fit a Barra 5.4 into mine. In the US I believe that the same engine is known as a 3V Triton AND it could be had with a supercharger option.

With that engine at least the purists can't deride you for fitting an "OHV dinosaur"

Of course this engine may end up being milles too wide.

I can't believe that Hemi's are cheaper than LS V8's in the US. That's just wow.

 

Yea most LS3 options run upwards of 8 from a dealer or around 4/5 for a junker without the trans. I’be picked up the 5.7, a stage II XCM trans, and a stage 2 cams and valvetrain upgrade for the same price I could have gotten a stock LS over here. And honestly I like the uniqueness of not running the basic LS or SBC

 

Good luck with your project, it sounds interesting. Being a Ford fan I wonder how a Coyote V8 would work. I know that the V12 is not an easy engine to modify for more power, but for a street vehicle I think they are adequate. My main concerns with the XJS are the ABS braking system, the aging electronic systems, and the suspension.

 

Well the ABS system is gonna get the good ole Yeetus deletus, because race car, duh. Though I did consider the 5.0 yote for a while, as the t56 magnum trans are easier and less finicky to build power on, but I couldn’t find a good healthy one for a reasonable price. -Mind you I don’t have room for a parts car or salvage title donor- I planned on doing a spring swap from the 2nd gen xk as they’re stiffer and fit the parameters. after reading some of ISCamerica’s posts, I’m gonna go with new pads and drilled/slotted rotors all the way around, and found some r888s that fit my set of HRE 501s. I have yet to pull the v12 yet but after looking at the trans dimensions the 8hp70 or the 6spd tremec would fit without any issue at all… or at least in theory. I’m going to look at the HEMI motor today and hopefully leave with it by Friday.