Has anyone fit the mid-1990s 4.0 supercharged 6 into a Mk2? While not as pretty as the 3.8 or 4.2, it's hard to deny the appeal of a lighter engine that delivers over 320 hp, quite a bit more than a stock Chevy 350 v8... and it's still Jaguar.

I apologize if this has been covered before. I only saw Doug's thread about the XJR v8 transplant.

If I have the doors to data we are talking about 325 hp and torque at 512@3050rpm and weighing about 530 lbs. 0-60 in about 6 seconds in the 4000+ pound XJR.

 

FYI,


That 4.0 liter supercharged 6 engine is way heavier than a modern GM LS1 engine. I am installed a 5.3 liter LS1 aluminum block/head truck motor that weighs somewhere between 400 to 430lbs and puts out 450-460 HP. It is very easy to get this level of HP as it did not involve much other than new computer, headers, mild cam. If you put a supercharge on an LS it is easy to get 600-800 on pump gas.


Doug has been doing impressive work but when comparing what he is doing to what I have done, I can tell you the GM LS1 went is with a lot less modifications. I am still doing minor tweaks but thus far my best time in 0-60 is 3.9 seconds

 

I know. Chevy engines are cheap, powerful, with a huge aftermarket, but I'm trying to avoid using the same engine that everyone uses in just about every hot rod and custom I see... no matter how practical, economical and logical it is to do just that. Besides, I want a classic Jag to *sound* like a classic Jag, and for that, it needs a 6 (or a 12).

My thought was that the AJ16 would provide the sound with better power and reliability with less weight than a stock 3.8 or 4.2 6, or a pre-LS SBC... for a lot less than rebuilding or hopping up the vintage Jag engines. I just didn't know how well it would fit. The real trick may be fitting a manual trans, but I think I found a solution from the SJR forum here.

 

I understand, I am a Datsun Z collector and on one of my 240 Z's I am going with a Nissan Skyline turbo to keep it all Nissan/Datsun and get the 850+ HP on the rear wheels I want even though that motor will cost $40K and an LS for about $15-20K will get close to the same HP. I guess that is why the Beecham Jaguar MKII resto-mod sells for $100K + and after doing a LS conversion and seeing what Doug did to make a late model Jag V8 fit, that price is reasonable for a company to make a fair profit.


If you go Jag I would opt for the V12 or minimum the V8. The reason is that any swap is NOT easy and a Jag swap is not going to be a walk in the park; if your going to go thru all that custom work and effort you should get the maximum HP to really make it worth while. I have seen on Youtube a MKII with a V12 so I know it can be done but whom knows how hard it is? I hope you have a lot of patience and a lot of money? I can tell you from my experience the 460 HP at the flywheel of my LS1 in the Jag 3.8s is to me a great power to weight combo. I think I would recommend to try to get at least 400 HP if you can as you will loose about 20-25% when it gets to the rear wheels.

 

This guy stuffed a v12 in a Mk2. He said he had to move the firewall back. It looks like a really tight squeeze!

H Craft Customs | Fabrication and Race Preparation ? If you can dream it, we can build it!

The v12 is a really heavy engine for the amount of power it puts out, but it sounds great.

 

That sounds way too challenging to me. A V8 will be tight too. I will check out the link later but maybe they just modified part of the firewall? Even I had to modify a small part of the passenger side. If it is the whole fire wall, that sounds like you will need to have a good body shop do that fab work as that is not typical a DIY job. Remember even Doug whom is one of the most incredible DIY guys I have seen will have something done by a pro shop.


I would then opt to copy what Doug is doing with a modern Jaguar V8 which is very similar to the Beecham approach if you want to stay Jaguar. Doug has posted a lot of great pictures and I am sure he would give you tips. Just remember to be patient these things do not happen like TV, they take a lot longer time regardless if you do some or all of it yourself. Even if you go thru auto shops to do the mods it will take time to keep the cost reasonable as there are good shops that would take it on at a more affordable price but it will be a job that they will do when they are slow. Thus unless you are Shack with no money limits it will still take a while to build. Good luck

 

Hellfish,


While not as much HP as an LS V8, you might not go for a swap at all but put a lot of money into the Jag straight 6 either the stock one or get a 4.2 liter E type built by people like TT Engines.
https://www.ttraceengines.com/about.html
They can squeeze 400 HP out of the 6 cylinder engine which is not bad for the Jag engines. I suspect the cost will likely be about $15-20K? but that is a total guess. You should call them and find out what a quality 400 HP motor will cost you. You will likely also need them to beef up a tranny to handle the power as well.


I totally understand if you are a die hard Jag fanatic as I am the same with my Datsun Z cars. Just remember you will pay a lot more but as long as your are happy that is all that matters.

 

I'm no stranger to fabrication and engine swaps, so I would do most of the work myself. My only concern with the engine is its height or the oil pan. I was asking if anyone had done it because it makes it a lot easier when I don't have to figure it out from scratch.

FWIW, my original thought was a BMW v12, but I kept reading how they are very expensive to make any repairs on. That may be the same case with the AJ16, but at least there's half as many things to go wrong.

I'd love to run the 3.8 or 4.2, but even assuming it's in good mechanical shape, simply upgrading the induction system to Webers or FI will cost more than buying a running AJ16 car... with more power. A $10,000+ rebuild is out of the question. That's what a classic Jag place in Austin charges for a simple rebuild or Stage 1 build. It's not like I'm going to race it, or at least not seriously.

 

There is no magic low buck solution to get modern performance on an old Jag. Remember a MKII to 3.8s did 0-60 brand new from the factory between 10.0 to 11.5 seconds. Building a simple rebuild or even a modest bolt on performance version is not going shave a huge amount of time off the stock values Jag obtained. If you want high performance with more reliability and keeping it Jag then I would highly recommend following what Doug is doing (XJR Mark2) as that is similar to the Beecham V8 Jag's. If you go to some odd motor like a BMW then you will likely be the first and engines other than GM that are not common swaps will have very little aftermarket items to help in the swap so that means a lot of custom fab work.


I think even if one does it all himself to get serious power you will spend well over $10K in parts & fab work in any swap so that is why I thought getting a really high performance Jag motor built would be something to consider. That way you just spend a lot of money but no fab work, no 1-3 years of your time, no frustration when you run into a problem that will require fab work that no matter your skill you may encounter something you will have to a specialty shop to resolve, etc.


Check out Doug's postings as he is sharing pics of the process of putting a modern Jag V8. If it looks like you are skilled enough to do that same build then that is the best to me if you are determined to stay all Jag but if not then I would save up and throw down the bucks for a high performance Jag 6 from a race builder telling them it is for the street then you will get high performance that is tailored for street use. To me just like Datsun's Z people thought in the 80's that an engine swap is cheap but when you add up all the other requirements to make it a truly balanced car in every way it will be more than you think. Either way you are not going to take a car that does 0-60 brand new at 10-11.5 seconds down to less than half that for pennies.

 

FWIW, the performance figures I've read for the supercharged 6 are 0-60 in around 7 seconds, and that's in a heavier car with A/C, power steering, and an auto trans.