Also, it is not turnkey, so at least $1000 for accessories.

 

I'm with you 100%. Ive begun my own LS swap, but I'm starting with the old LS1 and am doing it myself with the Jaguar Specialties kit. Once I learn how to do it and if I'm happy with it, I'll consider a new LS3 with maybe the 6L80.

You're better off with the E-Rod Connect and Cruise package from Chevy Performance.

http://www.jegs.com/p/Chevrolet-Perf...97705/10002/-1

This will have the LS3 plus a 4L65E with controllers. All you'll need is an oil pan, the front accessories specific to the XJS (mix and match pieces from various LS motors), exhaust manifolds that fit the XJS (doubtful the Chevy crate ones will fit), a fabricated exhaust system (maybe reuse old V12), and the swap kit. You'll also have to have a driveshaft made, and a few other odds and ends. So add another $3k or so.

I bought a Mast Muscle Car oil pan, which fits on paper. Most other oil pans need to be modified.

Anyway, an XJS with a modern 400hp+ LS drivetrain is my dream, so I'm rooting for you.

Padre

 

I looked at that connect and cruise package and decided against it. With that package you are basically are stuck buying the E-ROD package for an extra $2000. You are also buying a new trans; going for a rebuilt one saves another grand or so.

I was going to skip the E-ROD on my build...what do you think?

 

I'm in both camps, I owned an XJ12 with 350SBC many years ago, and I originally bought my XJS with idea of converting it to LS1 (10 years ago). SO I will try and be neutral.

I ended up staying with the V12 as I moved interstate. I drove the car 4500miles across Australia and decided to keep the V12, as I said that was 10 years ago now and it has only let me down once when the alternator died (actually the regulator).

So may I suggest before you go spending any cash, pull the V12 out and get the heads off it. Survey the damage. The V12 is a wet liner engine and if its just one cylinder, you may only need to replace one cylinder liner rod and piston. At least you know what you are dealing with.

 

I spent a lot of time on eBay looking at used combos - motor, tranny, wiring, ECU. That's really the way to go. Most complete for under $8k. Even with these, you've still got to worry about oil pan, exhaust manifolds, driveshaft, but the only accessory you've got to change is the AC compressor (at least with the JS swap kit).

The most complete and easiest used package would be from a GTO, LS1/2 with the 4L60. Older Camaro LS1s like mine are cheaper, but most are high mileage.

The only problem with the LS3s is they usually only come with the 6L80e - which no one has done yet in an XJS. Most kits are designed for the 4L60/65/70. Don't be tempted by the 4L80 - bigger, heavier, terrible gearing.

It's been a while since I added it up, but the C&C kit was about the same as individually buying all the components. With a used eBay pullout, you'll save at least $4k.

Check out user "camarohawk" on eBay for a good selection on older and newer used motors, everything from old LS1s to new supercharged LSAs. This will give you an idea of options and what sells for what.

To save a little more, look for the aluminum 6.2 truck motors. You'd have to swap the intake manifold, maybe accessories. I almost pulled the trigger on a low mileage 6.2 L86 motor, the same block as the new Corvette LT1s, but they don't come with a power steering pump.

If you do start with an LS3, go with the 4L70. No reason not to.

Padre

 

I have a 86 XJS with a 1st Gen sbc. I love the car. Great power and reliability. Great access. In fact I've swapped the motor in a weekend by my self, twice.
If I had the money I would have done the LS3 conversion with a better tranny. I had the sb and the T400 so for me it was a done deal.

 

Sorry to burst your bubble on this one rgp, but, although a V8 can sound good in its own right, a Jag V12 breathing through a decent exhaust sounds better than any V8, any day, and definitely sounds better than a Viper V10 (I mention a Viper only because my neighbor has one, and while I love the way it looks, Vipers sound like **** compared to a "liberated" Jag V12).

Here's mine:
Idle and Rev.MPG
Notice that signature V12 scream & crackle. You can't get that from a V8.

And here is one from down under:

 

I've often listened to this Tasmania video with delight.
This is where the screaming of a V12 is really worth.
However the sound of a "normal" Jaguar V12 engine in a factory XJS is by far not close to that screaming.
How is it possible to climb to such high revs and reach that sound apart from just removing cats and silencers? Does this mean lots of $$$ and loss of reliability?

 

Thanks for all the good advice Padre.

I checked out that seller on eBay and there are some interesting options there. In order to get up and running as fast as possible on the cheap ($3795), I am now considering this option:

2002 Camaro Z28 LS1 Motor Engine Drop Out w 4L60E 4 Speed Auto Trans 120K Miles | eBay

A couple questions if you don't mind though. I don't know a hell of a lot about engines.

1 - With a high mileage engine like this, besides individual parts failing, is there anything I should know about engine life? Is there anything an engine rebuild cant fix?

2 - Can you point me towards a few listings for the L86 truck engine you mentioned? I actually like the idea of changing out the manifold. I personally think the stock manifolds on the LS are kind of ugly and would prefer this one:

PRW 4237611: INTAKE MANIFOLD CHEV L-92 LS3 Series 6.2L/376 Fabricated Ram Air Intake Polished | JEGS

3 - I don't know one end of a wrench from the other. What is you estimate on labor for an engine swap out with the full drive train and accessories installed?

 

I think you are on the right track with a dropped out engine package like that LS1.

Those cobbled together LS home brew creations with separate ECM and TCM tend to not work well in the car. Drivabilty and real world performance is usually lacking.

Going LS is a great idea but the LS1 isn't worth the effort or expense. LS2, LS3, LQ9 are a totally different subject.

If you really want to control your budget use an LT1 & 4l60E engine pull. They can be found for less than 1/2 the price of an LS1. Using a LT1 which is a derivative of the SBC is a far easier and much lower cost conversion but will yield similar performance. In the end it will look cleaner too.

It's well known on the interwebs that an LT1 can be massaged to make similar power (310HP) to a LS1 with minor and low cost modifications. If you want to get inside the LT1 with a cam change they can make more HP and torque than a stock LS1 yet still cost less in the end that an LS1

Put a 3.875 stoker crank and a mild cam in that lt1 and make a 396... and you can trounce any stock normally aspirated LS engine and still have a lower overall cost in the end. With something like this traction becomes a limiting factor.

LS1 vs LS2: Which One is Better and Why?

LT1 or LS?... either way you are on the cusp of making the XJS great. A light weight responsive power-train is how the XJS should have come from the factory. The removal of more than 400 Lbs of dead weight over the front axle really wakes up the overall performance and handling of the car. Be sure to budget for lighter front springs.

Out back add a rear sway bar and 3:31 or 3:54 rear gears and you will have a serious street machine that is somewhat unique, comfortable, precise and sporting.

 

Paydase,
Rather than change the subject from the original post, I'll start a new thread with a few links to previous discussions we've had about modified exhaust systems on this forum. There are other threads as well, but, these should more than get your research started, and will provide a good place for other members to find info when they search the forum archives..

 

Sound is so subjective. Who wants screaming and crackling? Sounds like shrill Hillary Clinton rallying the short haired, comfortable shoe troops at planned parenthood to me. Generally speaking, most men and some woman appreciate the baritone thump of a domestic V8.

 

To each, his own.
As I said, the V8 sounds good in it's own right, and, I DO love American muscle, but, the sound of those two Camaros you posted doesn't get my blood churning nearly as well as the sound of that single yellow Targa Tasmania XJS (its much more fair to compare street legal racer, to street legal racer, than to compare the sound of my tired old Jag to that of an 11 second Camaro).

Just my

 

my $.02, which at this point I'm sure you don't want. Your going from a V-12 that went south on you and contemplating a Z28 LS with 120k on it? My son is always looking at T/As, Z28s, Ms, 5.0s etc...I always tell him as those thing get up to 100k and beyond beware, that those cars in general didn't lead a calm life. People usually don't buy a Z28 to "take it easy" or cruise in it slowly. LS's will do some long haul mileage but within reason you can be assured someone has put a Z28 one through its paces.

 

well, my Austin-Healy made corvettes Pee themselves... (had a cop drive 3 miles to give me a ticket one sunday morning) (ah the things you do when you are young)
the sound from 5k to 10k rpm was like a Kaw Ninja all hopped up on steroids and I would go hunt them in the rain...


like JagZilla says ...
I'll look for the new thread

 

A few things in no particular order:

- If you go with an older LS1, I would look for 100k miles or less. With regular maintenance, you'll find plenty that have reached 150, 180k+, but I'd rather have one that *I* can take an extra 80k miles. I look at it this way: if I put only 10k miles a year on my XJS with an LS1, that'll be a lot of driving and will last several years. By then, I may want to go with a better LS or I may be on a completely different project altogether. So think of *your* desired lifespan and yearly mileage for the car, and plan from there.

- If you go with a new LS3 (the autos are called L99), look for one in the 30-50k range. That'll give you plenty of carefree life.

- Also look at other Gen IV motors like the 6.0 L76/L77 from the Pontiac G8 and Chevrolet Caprice Police Package. You'll find them generally 2k less than a similar LS3.

- Whatever you buy, go with a shop that makes a living on selling these motors. You'll pay a little bit more, but you won't have a rod drop the first day.

- Truck manifolds are too tall, which is why they need to be swapped out. The Hi-Ram you linked is *way* too tall, so look for used or aftermarket manifolds for Vettes or Camaros.

Unless this is what you're looking for :


- The L86 (Gen V truck motor) swap is not practical right now (nor is the Vette's new 6.2 LT1). Custom accessory mounts to add a power steering pump and help it fit a swap are available, but run $1000+ just for the billet mounts.

- As for labor, it's really hard to say. Certainly less if you have a complete motor/tranny with wiring and ECU, plus the swap kit (mainly the mounts). The less custom work they have to do, the better. Also consider the premium you'd pay for a reputable shop who stand behind their work. I'd happily pay a premium for a shop I can trust and go back to with problems. My guess, a minimum of $3k, just labor.

- Here's a really cool option for $8500:
12 Camaro SS 6 2L L99 LS3 Engine 81K 6 Speed Auto Trans Dropout LS2 Turn Key | eBay

- Nice thing about that Turn Key motor, is you'd be taking a running motor to a shop with a lot of extra parts to make the swap.

- Finally, remember that with a swap, you are adding, effectively, *no* value to the car. In general, resale value will be no more than a comparable mileage stock XJS, V12 or no.

Padre

 

I certainly agree with your sentiments, but the LT1... eh. A mildly modded LS1 can put out 400/400 at the wheels easy, and do it less "wickedly". But with the cash, a Gen IV motor is definitely the way to go.

Speaking of exhaust clips, here are some of mine, and my 408 was as fast as the Wicked, but much more driveable.

Here's my LS1 GTO with just heads/cam, intake, and a Borla exhaust:


Here's the same LS1 after I built a 408 LQ9 for it:

Here's my 10-second Procharged LS3 Camaro:

Padre

 

ARE YOU KIDDING ME!!! one of the best combinations is a british chassis with Detroit iron. I just did it with my weak sister 6 cylinder and I wish i'd done it sooner. what's amazing is how little horsepower they get out of those 12 cylinders with so much size and weight! don't regret doing it, plenty of stock v12 around anyway.

 

Folks can have pretty strong opinions about Chevy swaps. These comments aren't nearly as harsh as some I've seen. In fact, it actually looks like you have more people supporting the swap than against it, when about 10 years ago you had one guy with you and 9 with pitchforks!

The car you have looks to be in excellent shape, and worthy of having a nice engine investment made into it. For that reason, I wouldn't suggest just getting another car. I would stick with this one, and go from there. That said, you definitely don't have to get an $8000 V8 to have a fun car. I got a rebuilt '84 Chevy 350 engine from Advance for like $1200 8 years ago (probably $1500 today). Sure, it only makes 200hp, but it's 300lbs lighter than the V12 and the car's still pretty quick. You have a lot of room between $1500 and $8000 to play with.

 

http://www.gomog.com/allmorgan/engineweights.html

According to this website a L98 350 is 600lbs and a 5.3 V-12 fully dressed for install is 680, where are you trimming 300lbs?? The 350 mid 80's is about 190 hp while the mid 80's V-12 is around 280hp.