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John's Cars, Inc. Chevy V-8 Conversion?

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William Mapstone

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I am a new member and was told by Basil not too just lurk.
smile.gif
So I was wondering what everybody thought about John's Cars Chevy V-8 conversion kit for the XJ Jags. Is it considered sac religeous to do such a thing to a british car? Ok let it rip!!!
 
I honestly have no problem with it if the Jag motor is toast. I don't think I'd yank of a good working V12 but a cheap Jag with a dead motor replaced with a Chev LT1 would be nice. From what I have heard JagsThatRun is a more quality product than John's car.

There are kits out there to fix Chev V8s in Porsche 928s for similar reasons.

cheers.gif


[ 12-09-2002: Message edited by: 78Z ]</p>
 
Welcome to the Forum. It's your car, do whatever you want!! I've researched the conversion kits a bit for my 79 XJ6, and John's Cars seemed to be the most complete, but at the same time, the most expensive. I think that it all depends on how much time you want to spend scavenging through the junkyard finding bits to work, which is what will happen with the cheaper kits. That may be the way for you to go, if you enjoy the thrill of the hunt. If you have the money, I would use the John's Cars kit and a crate motor, or at least a newly rebuilt engine. If it weren't for the V8 conversion, I believe a lot of these beautiful cars would have gone to the crusher years ago! Just my $.02
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Well so far I'm in more agreement with 78Z. I probably wouldn't take out a good running Jag engine, if the Jag engine was toast though...

One thing to keep in mind though, I've been told that it usually lowers the resale value of a Jaguar to put the V8 in.

And one last thing... a few years back I heard of a guy in Alberta who had a 454 V8 stuffed into a XJ12, now that would motor, although I'm also told a V12 goes fast too. See I still have split loyalties.
 
I've always thought it a great idea to purchase one thats already been converted..

The sales value is lower and the job is already done..

Of course if you already have the car.then go for it...

Chevy motors are bullit proof..and can produce nice power..

Most of all they are inexpensive and easy to work on if need be..

Most of the time..they just keep on running..and running...

So marrying the beauty of the Jaguar with the reliablility and power of a Chevy V8...should be a winner..

Let us know how it works out..or what you are considering..

If I had more room..I would definitely consider having one..

Sounds like fun!
 
FWIW, if you want to buy one done, have it checked out thoroughly as there are some really bodged cars out there.

John's Cars is kind of the standard of the industry but there are other companies out there.

I've had the pleasure of speaking with Jim at Suncoast Conversions in Punta Gorda, Florida and they sell everything from a basic mount setup that you can finish with your own skills to a complete setup.

Do bear in mind that John's Cars has been doing this for a nuber of years and they don't give out a lot of free time for questions.

Good luck on whichever way you decide to go.

A converted Jag done properly is a very nice car as is a stock one but the niceties are in the attention to detail with either route.

Jeb
 
I have to agree with Jeb- I have seen some real ugly conversions. I'd say that half the time needed for the conversion is detailing- engine, engine compartment, making everything look neat. After a recent attempt to sell my XJ6, I have decided to keep it in storage for a while, and hopefully convert it within the next few years. I need to get some time, money, and space first. (Who doesn't?
nopity.gif
)
 
Not to flog the subject, but I also agree with the above posts: John's is the industry standard, and although he is busy and rather tight with information, when I bought a number of parts from him and sent the money, he provided quick and cogent information. I have driven a Series One with a John's kit, backing up a Vette 350 engine, with no complaints. I now drive XJ6-C, done in LA, and again, no problems. Yes, it MAY lower the value compared to a well-running Jag, but my engine could only be used as an anchor, and I wanted to drive daily rather than be concerned about value. (Keep in mind that I also have an E-Type, converted to a Ford 289 by a slightly mad Brit years ago, and it still can almost outrun the CHP Mustangs. Note the "almost"...) If you wish, Jags That Run produced a step-by-step manual years ago, and I can send you a copy to see what the swap entails. Let me know.
 
I have a '84 XJ6 with an LT1/4L60E. I have owned this car for 5 years, logged over 80,000 miles since the conversion. I've replaced one OptiSpark and two water pumps - nothing else.

After reviewing the conversion that John's Cars made, the design definetely left room for improvement. So, my cousin who does conversions, decided to do better. We have done over 28 in South Carolina, in addition we have cars in Florida, New Jersey, Ohio and Georgia. The kit that my cousin fabricates is far superior than the others.

Yes, the value may come down. However, once you drive a car that has been properly restored you will really appreciate the virtues of the Chevrolet conversion. The power ratio is outstanding and it really brings out the best of this already excellent car. The key words are 'properly done'.

All the conversions that my cousin does are either LT1's or L98's and pretty much the entire car is gone over to make it roadworthy. No convesrions have been done with carburetors, since they are not as reliable and not as fuel efficient as injection. In addition to this custom radiators are used, as well as wiring harnesses and improved computer re-programming. All the electronics work, including the original speedo, tach, etc. There are plenty of other small details that are done, and extras can be also done.

We have converted a '82 XJ6 to use outboard rear brakes, as well as using PowerLok chunks. This car is most impressive when fitted with high performance tyres along with the PowerLok units. Seriously guys, a lot can be said about the restoration of this car with properly installed high performance power under the hood...

Regards,
joe
 
As for is the issue of car value after a conversion, it depends on what one wants out of their Jaguar.

Someone who wants their Jaguar to be a show winning concours example wouldn't dream of it (example: I saw a guy advertise his Series 3 Vanden Plas V12 sedan up here in Canada for $18,000 (CDN), way too much money! describes his car as a show winner). If you buy the car because you want to enjoy it and drive it, and don't really care that much about what it's worth, why not?

I'm still mostly a purist having said that. A friend of mine owns a 1987 Sovereign Series 3 sedan (with the Jaguar straight-6). In three years of car ownership he has had very few problems with it, and is very happy with it. As in my earlier post, if the V12 or straight-6 was already there and in good shape, I would keep it. If not, then I would have to consider my options.
 
Well, my car was bought with the intent of it being a daily driver, everyday type of car. I don't baby the thing, I drive it. The taxes are cheap, and the upkeep is minimal. My whole way of thinking about this car is that for what I have invested in it, one could buy a modern Japanese import. Well, there is no comparison in comfort, safety, looks, performance, etc. Yes, its 20 years old but it is a very serviceable car that serves it purpose. I figure in the last 5 years I have payed for this car and it is still in good shape. It should last another 5 quite easily.

Decisions, decisions. I guess it just boils down to practicality and what one wishes to do with the car...

Regards,
joe
 
Yes, I agree that it does come down to choices.

However, one more factor for Ontario drivers to consider is that so much salt goes on to the roads in winter. Often the engine of the car is fine still, but the frame and body are too rusty to even repair, and eventually cars just fall apart. My friends 1987 Jag has never seen winter, come summer time it is his daily driver and in the winter he finds a beater so he can garage the Jag.

The realities of Ontario.
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Z28Quetzal:
I have a '84 XJ6 with an LT1/4L60E. I have owned this car for 5 years, logged over 80,000 miles since the conversion. I've replaced one OptiSpark and two water pumps - nothing else.

After reviewing the conversion that John's Cars made, the design definetely left room for improvement. So, my cousin who does conversions, decided to do better. We have done over 28 in South Carolina, in addition we have cars in Florida, New Jersey, Ohio and Georgia. The kit that my cousin fabricates is far superior than the others.

Yes, the value may come down. However, once you drive a car that has been properly restored you will really appreciate the virtues of the Chevrolet conversion. The power ratio is outstanding and it really brings out the best of this already excellent car. The key words are 'properly done'.

All the conversions that my cousin does are either LT1's or L98's and pretty much the entire car is gone over to make it roadworthy. No convesrions have been done with carburetors, since they are not as reliable and not as fuel efficient as injection. In addition to this custom radiators are used, as well as wiring harnesses and improved computer re-programming. All the electronics work, including the original speedo, tach, etc. There are plenty of other small details that are done, and extras can be also done.

We have converted a '82 XJ6 to use outboard rear brakes, as well as using PowerLok chunks. This car is most impressive when fitted with high performance tyres along with the PowerLok units. Seriously guys, a lot can be said about the restoration of this car with properly installed high performance power under the hood...

Regards,
joe<hr></blockquote>

Joe, how much does a completely converted LTI 84 XJ6 sell for in the market today?

Sounds like a cool conversion.
 
The replies to this issue have been well informed and constructive. I work on converted XJ6 sedans wearing chevy V8 engines and they are impressive. There is only one comment I would like to make:
Throughout the responses, every one seems to agree that the Jaguar 6 or V12 power is comparative to the Chevy V8 power. Cosmetically, the car as original has an edge with the Jaguar polished aluminum looking at you. Before signing up for a conversion, why not look at an overhaul or at least decarbonization (as the Brits say) before making that decision? With Jaguar parts being readilly available and a bargain compared to other luxury imports (Mercedes and BMW) look at the conventional mechanical renewall process. An XK 6 cylinder block and head can be overhauled on an average for $4000. In the case of the 12 cylinder configuration, the cost is about $10,000 so the arithmetic changes. In defense of the V12, compare the smooth and subtle power available to any V8.
Both of the Jaguar engines have long longevity when properly rebuilt and properly maintained. At least 150K to 200K miles between large repairs is possible. I am maintaining many series XJ6 and XJS Jags that fall into that category.
To summarize this too wordy discussion, take a look at all alternatives before you sign up for John's. Proper Jaguar maintenance is available and can be an attractive alternative.
Best regards, Jack Farrington
 
While I'm very opposed to the conversion on an E- type or a 120 or a 150, an XJ6 poses no moral dilemmas for me.

I'm an american car guy just getting into British cars...to me on an XJ6 your going to drive long distances this makes sense.

I had the points go out on my Chevelle when my 6 year old daughter and I were travelling in the middle of no-where. Local parts house...no problems getting exactly what I needed.

Just my two cents. Keep us posted! I'd love to hear how your conversion went.

Christopher
 
I have a little problem with the conversion on an XJ 6-only a little problem.

I love Jaguars and a lot of the love affair has to do with the XK engine.

My infatuation goes so far that I have a spare 3.8 E type engine in my shop just to look at. The XK engine is an engineering marvel.

Well actually it is not entirely pure because I altered it to accept an XK 120 pan, the front timing cover and pan have been bored to accept a modern front oil seal. It has been cosmetically altered including cast on numbers to appear to be a 3.4 litre XK 120 to be a spare for my XK120 rdstr.

If you decide to take the Jaguar engine out I reccomend that you keep it in a safe place because some day you may fall in love with your car and want to put it back together. An XJ6 with a manual transmission, Wire wheels, British racing green with biscuit interior is a car that I lust for.

Without the XK engine it is of no interest.

It would seem
more practical to just buy a nice chevrolet if that is what is wanted.

Never never consider swapping an E,XK120,140 or 150 or a MKI or a MkII.

I guess swapping an XK engine for a chevy does bother me more than I thought when I started to write this reply. The XK engine has a lot of history-- it was copied somewhat from Bugatti
But Bugatti copied his engine from Harry Miller.
Look at cross sections of the Miller race car
and you will recognize it as the grandfather of the Jaguar XK engine. (Harry Miller was a mechanical genius designing racing engines, racing cars in the 1920's&30's.


Dave Smith
zephyr27@gte.net
 
I appreciate the value of having Jaguar engines in Jaguars..

Still a Chevy LT1 V8 easily pumps out over 300hp and is as reliable as could be.

Thats always a factor in using a vintage beauty such as the XJ series car..

I've always been more into the outer beauty and total performance package vs. originality...

And most important of all..I respect others desire to keep the cars totally as designed from the factory...........
 
I appreciate both sides of this issue.

As a Ser III XJ6 owner, I can postively state that about the only way to improve on this car would be to add more power :smile:. They are fabulous machines....300+ horsepower would only make them that much more enjoyable.

Frankly, for myself, the only reason I would install a V8 is to gain easy horsepower.

Assuming a dead 6-cylinder motor, and assuming one would want a first class conversion with all new parts, new or rebulit engine and trans, fuel injection, and all the details ironed out to the "nth degree", I seriously doubt a conversion could be done for less than the cost of a rebuilt Jag 6 cylinder.

Of course, if you went with a used motor and trans, and carb'd instead of F.I. you may be able to do it for less.

I agree that it wouldn't seem right to do this with one of the "classic" Jag models but, hey, XJ6's are not exactly rare.

Lastly, I'm "for" anything that will keep these cars on the road as opposed to sending them to the scrapyard.

Doug Dwyer
 
Ultimatly it is what makes YOU happy that is the most important factor. If you like the feeling of opening your hood and showing the XK engine off, or you like the sound and feel of a unique straight-six, or you are calmed by continuinge the history of the marque, or you are driven to "make it new again" then stay with the Jag powerplant. If you like the looks of the car but not the idiosyncrasies of a somewhat less than modern mill, or if your origional block is now so much broken china and a major restoration or a new one is beyond your wallet then maybe Detroit is the way to go. Forget other people's judgements; they aren't driving (or buying) it!
PS: if you do convert remember to upgrade the rest of the drive trai, too. Once, in my misspent youth, I melted an XJ engine and, being broke, threw a 327 into the empty bay. 2000 miles later, on an exhilarating but highly illegal run up the moutain toward Lake Arrowhead, the rear end twisted entirely out of my Cat.
Alan
 
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