Jag V-12 Engine

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David Rayner
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Jag V-12 Engine

Post by David Rayner »

I'm in the parts collection stage of building a Model T, C-cab panel van. I don't have a great deal yet but I buy what I think I'll need as I find it. I was always intending to use a Ford engine and probably a Clevo and I definitely want a Jag rear end. Looks are very important to me and as the motor will be uncovered, it has to look the part and when it comes to the looks of a North American V-8, nothing beats the giant valve covers of a Ford 427 Cammer, 429 Shotgun, or a Chrysler Hemi but those engines are rare and exotic, and very expensive so I was going with what I think is the next best thing, a Clevo. Well, just the other day I was at a good mate's house and noticed a very neglected series 3 Jag up the back of his property. I asked what he was doing with it, hoping he'd say he was going to part it out because I want a Jag rear end. He said he wants the front end only for some project or other and then said "tell you what, if you take the front end out for me, the rest of the car is yours". Yahoo, a Jag rear end for a few hours of work. Wanting an LSD and knowing that only some 6s have them but all 12s do, I asked if it was a 6 or a 12 to hopefully save the trouble of jacking it up and turning a wheel to see if the other turns with it. It's a 12. That told me what I needed to know about the rear end but on the way home, it occurred to me that when it comes to the looks of an engine, something that turns me on just as much as giant sized valve covers is pipes, and the more the better. You can see where I'm going with this.

To put it simply, I've just been given a V-12 Jag engine of around 1981 vintage. It's complete and my mate said it ran when he parked it there several years ago. I've seen plenty in various Jags over the years and have always liked them but never really considered one for my rod until now. As for its looks, the valve covers are very narrow but they're also very long, and with 12 intake stacks and 12 exhausts there'll be 24 long, chrome, trumpet-ended pipes on display. A 12 cylinder Jag is 326 ci, SOHC, fuel injected, all aluminium, and in stock form produces around 295 hp and 300 lbs/ft of torque. Most were put into luxury saloons (this one is in a Daimler Double 6) and as such, are in a very mild state of tune as are most North American V-8s and like those, the Jag can be livened up somewhat. There are all manner of go-fast goodies, cosmetic parts, shops that specialize in them, etc.

So, for my rod which being a C-cab panel van is unusual in itself, what are your thoughts on such an unusual (for a rod) engine? Does anyone on this forum have one? When so many rodders have robbed the rear ends out of Jags, why haven't they taken the engines as well? Is there some reason you wouldn't use one in a rod? If it's the expense of rebuilding one, I got it for free so that negates some of the cost. In fact, I can have the entire car minus the front end so I could sell everything but the motor, trans, driveshaft, and rear end to recoup some money. If it's complexity, I've been around Japanese bikes all my life, am quite comfortable with DOHC, 4-valve engines that have way more cylinders than they need and so to my mind, a V-12 Jag is just like a bike engine, only bigger. If it's the length of it, the frame has yet to be built so that's not a problem.

I know that many Jags have had American V-8s put into them but I'm not sure why. If it's because the owners didn't want to spend the money it takes to rebuild a Jag but had an old V-8 lying around, that makes sense to me but I'm in the opposite situation. I'd have to buy a Clevo and everything that goes with it but I have a complete Jag engine that cost me nothing. I also like having something a little different to what most other people have. It's why we love hot rods compared to production cars but I want not just a hot rod, but one that's a bit unusual. That's why I chose a C-cab van. Should an uncommon body have an uncommon engine to go with it?

Any advice would be gratefully appreciated.

Dave.
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Re: Jag V-12 Engine

Post by enjenjo »

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T1916
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Re: Jag V-12 Engine

Post by T1916 »

Hi Dave

Stanga (Ray) on here has a V12 Jag in his 27 Chrysler roadster with Quad turbos. I tried to find a pic but looks like they are all gone to photo bucket. I have a mate that,s just built a T panel van up Noosa way (pm your email and I can send you a pic).


Cheers GT.
Maffra
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Re: Jag V-12 Engine

Post by Maffra »

Hi David,

I have a recollection that Peter Gough (Toprodz) may have been involved with fitting a Jag V12 to a rod. I am fairly sure there is a pic of it in one of his numerous posts on here somewhere, but I am sure Pete will jump in and clarify this :) .

Personally, I think using a V12 would be a great project 8) . . . certainly fairly unique and different to the usual Hemis, Fords and Chevs :wink: I look forward to following along if you go that way :)

Thanks and regards :)
Maffra

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zuffen
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Re: Jag V-12 Engine

Post by zuffen »

The 1982 Jag/Daimler V12 is an HE or Mays headed engine.

This is the 2nd incantation of this engine and was way more economical and efficient the earlier engine.

They had Lucas fuel injection and were prone to engine bay fires.

The fires were caused buy lack of maintenance where the fuel hoses would leak and the distributor, being in the valley, would set the fumes alight.

Not a cheap engine to work with but I think it would look the goods.

I have a friend with a Ferrari V12 engine'd T bucket and all those pipes look wicked.

Setting up ITB's would be a challenge and expensive but I'm sure there are ways to make it happen.

Most Jags that ended up with V8's did so because the owners were too stingy to maintain the original engine as it should be and then were too stingy to fix it so the cheap solution was bolt in a US V8 as they used a Th350 gearbox.
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David Rayner
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Re: Jag V-12 Engine

Post by David Rayner »

Thanks for the positive feedback. OK, let's talk about pipes. As a kid, I built lots of Monogram models, including the Red Baron. It was a German-themed T-bucket with a 6 cylinder engine and had a set of pipes that I just fell in love with but of course, they were all on one side with just a single carb on the other (see http://www.showrods.com/ for models if that interests you and to see the Red Baron, go to http://www.showrods.com/gallery_pages/red_baron3.html ) .A few years ago when I was in the "early thinking about it" stage, I was talking to Ian Cameron and mentioned that rather than the common-as-armpits V-8, I'd consider a 6 purely to have those pipes. He advised against that, saying when I wanted to sell it (or my kids had to sell it when I'm in rodder's heaven) it'd be almost worthless. Lo and behold, I see in a recent issue of Cruzin' magazine that Ian has built a T-bucket with a Holden 6. He says it's a tribute to what rodders did back in the day, using whatever was cheap and accessible and for Aussies, that's a Holden 6. It's not a bad looking car and pretty much how I imagined a 6 cylinder bucket would look, but a Holden engine has all its stuff on one side. I'd have used a Ford cross-flow with 3 Webbers so there'd be 6 pipes on each side. The Ford's head is also twice as wide as the Holden's so that's another plus. As looks go, I still think that'd be great but when push came to shove I was going with a V-8 because I can't stand the sound an inline 6 makes. If I really wanted to, I could have the cam altered so it fires as a 3-cylinder engine but with 2 firing at a time. As I've said, I've been around bikes all my life and quite like the sound of a triple. In the car world, that sound would be unique. Has that ever been done? I know of a Honda CB-750 that's had its cam altered to make it a 2 x 2 twin purely because the owner loves the look of it but detests the sound of an inline 4 so yes, it has been done.

Back to the situation at hand. The Jag engine is mine if I want it and it costs nothing but the time it takes me to extract it. It's complete with all accessories and electrics plus a trans, drive shaft, and rear end. Although they lack the wide valve covers of a hemi engine or even a Clevo, I like the look of them and I love the idea of 24 pipes coming out of it. It'd look something like the engine of the Red Baron, but from both sides. I quite like the sound of a V-12. From what I've gathered by reading about them over the last few days, all of their faults can be rectified and they can make way more power than they do. Will I do it? More research needed and I'll probably talk to Jag shops and members of Jag clubs to find out the finer details. Do I want to do it? HELL YES!
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Re: Jag V-12 Engine

Post by zuffen »

I wouldn't worry about resale values as we don't build em to make money.

You may not get a great welcome from Jaguar Club Members, as they are pretty funny about their cars remaining "as built".

If I was in your position I would be grabbing it all and going from there.

If the engine is any good use it. If you later want a V8 it isn't impossible to change it out.
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Re: Jag V-12 Engine

Post by scooterscum »

If using the jag motor I'd be getting it running and test drive before stripping the front end. Might give you an idea of what work (if any) the drive line will need.
David Rayner
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Re: Jag V-12 Engine

Post by David Rayner »

Zuffen, Resale value; my thoughts exactly. Jag clubs; you're probably right but this car's body is so bad it's beyond saving so all the running gear has to go somewhere. If they'd prefer it went to them for spares, so be it but with all the Jag rear ends in rods, if a future shortage of anything takes their cars off the road, it'll be that. Grabbing it all; my wife is loath to having junk cars on the property so I might go to his place take all I can get from it, give him the front end, and call a bloke nearby who takes old cars away for free. Then I'd bring just what I need home on the trailer. If the engine is any good; I'd do the usual checks like seeing if it turns over, etc., and if it does I'd build the car I want and run the motor around for a while before I spent any real money on it. If I like it, then I'd rebuild/modify it as required. If I don't, yes I could then buy a Clevo and use it. Much easier to shorten the chassis than to lengthen it.

Scooterscum, I'd love to drive the car but the body is too far gone from being in the weather for so long. I'll see if I can turn it over and if so, I might put fresh oil in it and see if she'll start. That's as much as I can do. If I were going with a Clevo, pulling one out of an old Falcon would be the same and given their age and that Clevos can't be bored very much, I may not find a useable one. That means buying a new block from Dart or Ford Racing. Then I'd need CHI heads, manifold, carbs, ignition, etc. Assuming it turns over, suddenly the Jag is not such a bad proposition, eh? It really comes down to which engine I'd prefer and at the moment, I'm leaning towards the Jag.
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Re: Jag V-12 Engine

Post by enjenjo »

They had Lucas fuel injection and were prone to engine bay fires.
I have seem one fitted with Bosch fuel injection from a BMW six fitted, one set to each bank. It's a batch fire system so can be triggered by the BMW computer no drama. It did need custom machining on the manifolds, and custom fuel rails, and of course a custom PROM, but worked very well.
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Re: Jag V-12 Engine

Post by zuffen »

David,

If you do attempt to fire it up check carefully for fuel leaks at the injectors and keep an extinguisher handy.

When running my Insurance business we repaired heaps of V12's that had had engine bay fires as we were the nominated insurer for all the Jag Clubs in Australia.

The Members are an interesting lot to deal with.
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Re: Jag V-12 Engine

Post by fredeuce »

The V12 is a good engine with lots of performance potential. They have been stretched to 7+ litres. The only concern I would have is the condition of the major castings (block and heads) . I have heard various stories of these corroding over time and developing leaks which are a costly problem to repair. Service records if properly maintained regarding coolant would be essential. Given what you have described about the vehicle I doubt if you have that. Given the age I would be looking carefully at the coolant inside this engine to see if it is coolant or just plain water and take your chances from there.
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Re: Jag V-12 Engine

Post by mgyxjc »

David.. though you have the 2nd Gen HE 5.3 V12, it’s the earlier pre HE 5.3 (which LOL, has a Hot Rod link in that it’s commonly called a ‘Flat Head’) engine that is usually ‘built’ for a performance outcome (I’ve a 'worked', bored & stroked, 6.4 litre version) . Remember that you’ll need deep pockets.. multiplying parts by 12 rather than 8 adds up but that aside, they are a sweet motor and sound great on full song.. a T700 wakes them up, a 5 speed manual lets them work really sing. There are multiple throttle body set ups available.. ie 6 dual throat EFI TB’s on Weber manifolds or a new one that has transverse runners and 12 single EFI TB’s.. with an ECU to drive them, that’s into 5 figures.. Down draft Webers are a cheaper proposition, just not as effective as EFI.. There is a guy in the U.S. that casts dual 4 bbl manifolds.. effectively two V6 manifolds with a 4bbl on each.. if you can get them, they run to about Aussie 2k landed (just for the manifolds). The Jag V12, for sure, isn’t a stranger to Hot Rods.. there was a South Aust. Jag V12 T-Altered that campaigned on the strip here for many a year and a later reiteration of that car, as a Rail, ran 8.5’s in the Qtr. When all the induction crap is taken off they are a tidy mill, narrow, just 60 degrees
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Re: Jag V-12 Engine

Post by jeffa »

You asked originally why there weren't more Jag engines in rods.
Basically they are long.
Most guys want to build what's practical and easy to get going, especially for a first build.
A small block Ford or Chev will fit fairly easily in an early Ford engine bay. Firewall chop, sure but the chassis can stay the same length as stock.
Once the SBC or Ford is in, connect up a fuel line, a wire to the coil and you are away.
That ease meant more small block V8's in rods. That spawned a thriving business in hot-up parts. Which means these parts are plentiful, and cheap.
Which then feeds the decision to go small block V8.
Round and round it goes.

But you are not limited by a short engine bay.
And your engine is cheap.
And to get you going you dont need hot-up parts.

What have you got to lose?

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Re: Jag V-12 Engine

Post by Sudsy »

David Rayner wrote:Zuffen, Resale value; my thoughts exactly. Jag clubs; you're probably right but this car's body is so bad it's beyond saving so all the running gear has to go somewhere. If they'd prefer it went to them for spares, so be it but with all the Jag rear ends in rods, if a future shortage of anything takes their cars off the road, it'll be that. Grabbing it all; my wife is loath to having junk cars on the property so I might go to his place take all I can get from it, give him the front end, and call a bloke nearby who takes old cars away for free. Then I'd bring just what I need home on the trailer. If the engine is any good; I'd do the usual checks like seeing if it turns over, etc., and if it does I'd build the car I want and run the motor around for a while before I spent any real money on it. If I like it, then I'd rebuild/modify it as required. If I don't, yes I could then buy a Clevo and use it. Much easier to shorten the chassis than to lengthen it.

Scooterscum, I'd love to drive the car but the body is too far gone from being in the weather for so long. I'll see if I can turn it over and if so, I might put fresh oil in it and see if she'll start. That's as much as I can do. If I were going with a Clevo, pulling one out of an old Falcon would be the same and given their age and that Clevos can't be bored very much, I may not find a useable one. That means buying a new block from Dart or Ford Racing. Then I'd need CHI heads, manifold, carbs, ignition, etc. Assuming it turns over, suddenly the Jag is not such a bad proposition, eh? It really comes down to which engine I'd prefer and at the moment, I'm leaning towards the Jag.
If it has been sitting for years probably a waste of time trying to get it to start. The injectors would probably be gummed up and the prince of darkness ecu probably wont like being woken up lol. Definitely worth using with lots of potential. Being a V12 it may have the turbo 400 trans as well. Plenty of aftermarket ecu's to use to control fuel and spark. As Fred mentioned check all the galleries before spending any $$. Nice blower sitting on top would look great. Love anything out of the ordinary. Keep us updated
Regards Bob
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