So here is what I want to know, what are the weirdest engine swaps that have ever been done to a jag? Mainly pre-xj40.

Reason being is that I want to restore a s1 or s2 xj and install a modern engine. And because I feel that the antiquated sbc is vastly overdone and also a travesty that just doesn't do justice to jaguar, though I mean no offense to anyone who has done it as it does make a ton of sense. I want a classic xj with modern drivability, including steering and suspension, but this thread is about just the powertrain. Ideally I would like to install an aj-v8, preferably the aj-34s. However I understand that this is likely not feasible and even if it is it will probably be cost prohibitive. So my thoughts turned to the Cadillac northstar because of its complexity, uniqueness, performance, simplicity to retrofit and compatibility with older GM transmissions like the th400 and 700r4.

So, anyone have any thoughts or experience with this type of swap?

 

In my opinion, the best path to achieving what you want is an LS1 swap. The "LS" engines are used in GM V8 cars and trucks from the late 90s through present production. The LS line is entirely different than the old-style SBC engines, which finished their run with the LT1 series. They can be purchased in a variety of sizes (4.8L, 5.3L, 5.7L, 6.0L, 6.2L, etc) and with a variety of features (displacement on demand, electronic throttle control, etc.) These engines are extremely reliable, fuel efficient (for V8s), and incorporate pretty much every modern feature on the market except direct injection. These engines bolt up to mostly all of the Chevy transmissions, both new and old, including the more modern 6-speed automatics. There is also substantial information and kits available on doing the swap in Jaguars and other cars.

Compared to the LS line, the Northstar would be unique and complex - that's about it. It cannot compete with the LS series on cost, efficiency, reliability, power, availability, etc. Notice that Cadillac gave up its Northstar line of V8s in favor of the LS engines.

Whatever you choose to do - keep us posted!

-Dave

 

A couple of other options I can think of are the newer Jaguar straight sixes, AJ6 and AJ16. The XJRs came with a supercharger setup that put down some good power. I've also seen where someone put a Toyota straight 6, like out of a later model Supra, don't remember the specific Toyota nomenclature, in an XJS, and those things put out a ton of power.

Just some ideas.

 

Thanks for the input guys. Its not necessarily that i'm looking for huge power out of a motor swap, don't get me wrong I do want more, but that is not the main goal. I suppose the main goal would be overall uniqueness with regards to technology. LSx tech is good and all but its still just the newest evolution of the sbc. Amazing engines and I do love them, I just don't feel like an LSx fits in a jag "spiritually". I would really love something that has a high performance sound to it without sounding like a 60's Chevy pickup with an exhaust leak. I would love all aluminum DOHC and maybe even VVT. Which is why I thought of jag's AJ-V8 and then the northstar. Aww hell, let's get nuts and say turbo boxer 6 from a Porsche, or Ferrari v8 (can anyone say"Jagarri" haha(think "ferrambo"look it up if you don't know what it is)).

 

Nissan 2.8 or 3.3 Diesel engines used to have quite a following.

Although as you are in the USA, maybe a GMC 6.2 or 6.5 diesel.

Hardly cutting edge though.

 

You could always try a Roll Royce Merlin Engine! I just happen to have two for sale at the moment!! Here is a link with someone who did it with some kind of home made job. I must admit however, the car is an aesthetic nightmare (I am guessing it may be also a nightmare to drive!);

http://forums.finalgear.com/general-...2-beast-38954/

 

Yea, the LS1 is more about practicality, reliability, and performance. If you're looking for uniqueness, it's probably not the best choice. A lot of people do LS swaps.

How about the Lexus V8? You might be able to get an engine/trans combo out of one of their large sedans. And it will say Lexus on it, which is cool!

There's also the Mercedes S600 coupes and sedans from the 90's - didn't they have V12s? Again, you could probably get an engine/trans pullout relatively easy. Not high on reliability or fuel economy, but it's Mercedes so it will have some cache.

Whatever you do, check the exhaust for leaks - you don't want to sound like an old pickup! ;o)

 

Consider the practical and technical aspect of an engine swap. The engine has to interface with the transmission and the rest of the car and be tunable.

You can swap in something like a toyota V8 / transmission but the aftermarket doesnt offer the tools to tune most engines for the application. Post 1996 engines would need multiple O2 sensors, varous speed sensors and you'll be doing some creative wiring to get the speed-o, tach & temp gauges to function properly.


Any engine swap will need to be tuned for the chassis. Differences the intake design and differential ratio will have to be accounted for in the tune. You can stuff just about any motor into the large engine bay of an XJ but getting the tune right and getting the transmission to shift right at all points is anther matter.

In my opinion the LT1 / LS is probably the most refined and tuneable swap. These engines use a PCM that runs the engine and transmission together so it offers perfect shift points and driveability with features like proper 3rd & 4th gear lockup modulation, lean cruise and closed loop SFI for smooth operation and driveabilty. The most important part is that the aftermarket offer the tools to and resources tune the PCM to get all the bugs and driveabilty items sorted. For me there is nothing exciting or exotic about a vehicle with an unusual engine/trans that doesn't drive right under all conditions.

I dont understand the loathing of the SBC engine swap...an early TPI motor backed up with a 700R4 is much more drivable and just as smooth as what Jaguar produced. Sorry but the V12, shackled with a TH400 or BW 3-speed and tall diff is not a recipe for driveability or performance. I've done a SBC swap and used Ford V8 fluid filled motor mounts and it makes the engine just as smooth as the straight 6 that came out. The mounts are the key and some of the retailers that offer SBC swap kits have horrible motor mount designs. That's the issue with refinement on Jag's with SBC in my experience.

 

That merlin engine is pretty cool! Too bad it isn't more realistic for use in cars.

I had hardly even thought of other engine brands for the same reasons that icsamerica just talked about. It would be an electrical and tuning nightmare. And just to get this straight I don't loathe the sbc swap, I just like more of a challenge; I like to be a little different sometimes; and it just isn't for me, like some people drive Hondas. The sbc just doesn't float my boat, however I do respect it as it is a very practical performer in every way.

I like the AJ-V8 because I like the idea of staying true to jaguar and because it's an awesome engine, however I do realize it would be an electrical and tuning nightmare, not to mention crazy expensive. Meanwhile the northstar is cheap and has a standard Chevy bellhousing pastern, it also uses the same electronics hardware as any other newer GM. The aftermarket for it is minimal but it is there. The bottom ends are virtually bulletproof and there are oversize studs available that remedy the head gasket issue.

Anyone check out the "ferrambo"?

 

Oh, I don't know... it's not like the use of a Merlin has never been done before as this link demonstrates!

 

Northstar + 700R4 = some after market support, high price per HP. Northstar is surprisingly heavy for an all alu motor, LS weights slightly less.

Buick 3800 Turbo + 4l60E = very good aftermarket support for engine and transmission, low price per HP, intercooler piping can be challenging. Excellent power to weight ratio and set back V6 would be great for weight bias. Buick 3.8 is smooth and has ample torque. Could be setup for excellent fuel economy and great power.

LT1 + 4l60E + turbo = very good aftermarket support for engine and transmission, low price per HP, intercooler piping can be challenging.
Probable more HP than the chassis could handle.

6L Jaguar V12 + 4l80E = would require whole 1994 - 1995 car for engine computer , trans and wiring harness. 4l80 is not geared ideally for Jaguar v12's power band. There are alternate gear sets for the 4l80e but no way to tune the Jaguar computer or engine.

Nissan VG30TT + 5 speed = engine would have to sit far forward for turbos to clear steering, good after market ECU support. Poor low end torque not ideal for heavy XJ.

SBC 400 + 700R4 + Lingenfelter super ram Intake + Rhoads Lifters = What I'm working on, excellent HP per dollar, smooth and amazing torque well suited for heavy XJ, intake is unique and somewhat classic, Rhoads lifters offer torque and high RPM performance. 700R4 geared well for XJ, lots of aftermarket trans and ECU support.
you can see it here.

 

If you're set on the Northstar then go for it. Doing something new and unique? I've been there - get ready for the pain!

Here's my swap - the page hasn't been updated in a while, but you get the idea:
Dave's Jaguar XJ6 LS1 Swap

 

It would seem that I am more set on the N* than I thought. Great list on different engine options, pros/cons icsamerica. Quite helpful. Actually i'm really liking the Nissan idea, however perhaps a vq35hr instead, still probably has better torque and power than the factory jag 6. That will be something to ponder.

Fastcat, I've already come across and read through your whole build page, quite enjoyed it. But coming to the end was like watching a movie and then finding out at the end that you won't know how it ends until you see the sequel. But it looks like you're doing a fantastic job and i'm sure it will be a blast to drive! Ooh and I think it was a wise decision to switch from turbos to a supercharger, piping probably would have been a royal PITA!

Now what I really need is to come across the right S1/2 xj. I've seen some decent condition S3's recently with engine issues for cheap but if i'm going too put this much time and effort into a project I would rather get my favorite of all the available options.

 

Has anyone ever considered a BMW straight six? Great freaking engine, and I had one in a 330CSI. Strong engine, and would fit nicely I would bet!

 

Now there's an idea I really like! Especially if it's from an "M" car! Those can make a bunch of power and look great too, especially when they have individual throttle valves for each intake runner. Could even paint it up to look like the factory jag I6 and I bet most people would never know the difference. And it would be simple enough to find an old m3 that was wrecked for cheap as a donor. Use engine, Trans, and wiring from wrecked BMW. Couple performance mods and you could have a ~350HP I6 xj with modern powertrain!

 

If I were forced to do this, I'd go for the Toyota Supra I6. You can buy them dirt cheap ($2k) all day long, and there's no limit to the performance upgrades. If you're gonna do it... DO eet!

 

Put a series3 injected engine in it, with a 5 or 6 speed auto. They make adequate power, the only thing holding them back was the 3 speed auto and high gearing.

 

Exactly my thoughts. Strong, durable engine, simple Bosch EFI, potential for added power with a little head work and some tweaks to the air flow sensor. With a 5 speed it should move pretty damn well. Personally, it'll be a 5 sp manual for me, this is the first auto trans car I've ever owned and it's only because I love these cars and they didn't sell them with a 3rd pedal. I'm starting to look into options for doing the conversion soon.

That said, if you're going to do the swap my first thought would be a BMW straight 6. The S engines from the M series cars are going to be pricey but M50s can make good power and can be had pretty cheap. If you're going for bigger power it's LS or nothing. Nothing else will be as efficient, reliable, powerful and fun. Northstar would be a complete waste of time, garbage engine.

 

That is actually what I am putting in my MKV. A series 3 XJ6 4.2 litre!

 

Series 1, 2, and 3 all had manual trans options. IIRC, S 1 and 2 came with Jaguar 4sp with
O/D, and series 3 came with 5 speed. There are complete kits available to add Toyota supra 5 speed to XK motor. These have been around for a while, have not heard any complaints.