V12 engine mods, cheap

Frenchyd - Thanks for all of the Jag and V-12 knowledge. Every time someone posts the TWR V-12 racing videos, I immediately start searching for one!

dyintorace wrote: Frenchyd - Thanks for all of the Jag and V-12 knowledge. Every time someone posts the TWR V-12 racing videos, I immediately start searching for one!

The noises made by the Jags at the Mitty were glorious. It was almost enough to make me want to challenge one.

MrJoshua wrote:

dyintorace wrote: Frenchyd - Thanks for all of the Jag and V-12 knowledge. Every time someone posts the TWR V-12 racing videos, I immediately start searching for one!

The noises made by the Jags at the Mitty were glorious. It was almost enough to make me want to challenge one.

Agreed!

In reply to mancha: It would fit easier than a 289.. It's really Narrow. Only about 22 inches wide but it is a bit long, 35 inches.. You could possibly cut off about an inch of that length simply by going from a 4 grooved fan belt pulley to a 2 groove pulley.

The IRS would be really easy. It comes already caged and while some body work would be required it's not out of reach of a semi talented D.I.Y'er.
Since Ford Bought Jaguar it's even semi-legitimate..

In reply to MrJoshua: Too bad I'm such a computer luddite.. If I weren't I'd take a couple of pictures of the bare block and that alone would generate lust.. Once you take one apart and look at the quality and size of the pieces it's made from you'll wonder how Jaguar ever sold them so cheap..

Polish one all up and you have a wonderful display piece for your man-cave..

In reply to calvindoesntknow: Horsepower is one of those things where it seems more is better. Well Not really and it depends.. 450 horsepower is a massive improvement over the factories stock 300 and simply won't come from easy bolt on's

To make things overly simple, The factory spent a lot of time and money to make as much power as possible. OK they were conservative and didn't want engines blowing up before the warranty expired. Even if they had gone crazy without regard the warranty the package had it's limits.

More power was available at higher RPM. Mechanically the engine is easily capable of much higher RPM. However it's clients would not like gutless at Low RPM, not with the heavy cars they wanted to buy.. So they made the trade. More torque and power at low RPM at the cost of Power at High RPM..

Increase the compression ratio to around 10.0:1 and use higher lift cams and bigger ports is the formula..

However you are still lugging 4200 pounds and a light 4 cylinder will beat you with his Turbo/supercharger kit. The XJ-S will get down around 2700 pounds with some ruthless stripping.. With great attention and effort 2300 pounds can be achieved. Now You have a chance.. Forget the civilized ride and quiet elegance..

All Race and high performance Jaguars used the early Flathead because the H.E. was made for better fuel mileage and lower emissions not increased performance.. It was patterned after the Chevy fireball chamber of the 40's and 50's. Designed to burn a very lean fuel mixture not make maximum power.. The high compression it used was simply a crutch to get the fuel to swirl..

While the intake flow of the H.E. can be improved what really kills the power is the shrouded exhaust valve. To get the H.E exhaust valve to flow anywhere near the same amount would require a lift of almost .750 (stock is .375)

On top of that you would need to alter the ignition timing very radically. If you frequented the European swap meets / wrecking yards.. (yes the timing is altered in European destined V12's) you might be able to source the bits needed to get the proper timing in the distributor to then make the power you seek with the H.E. heads.. However, even then you would approach the point where use of a megasquirt is not a significant bigger time commitment.

Making 450 horsepower with the earlier flathead is a much easier proposition even if it does mean replacing perfectly useable pistons with aftermarket pistons.. The advantage of the flathead is yes it bolts right on. but the H.E pistons won't work. Since you are replacing the pistons anyway you may as well go to the biggest bore practical and pick up all those additional horsepower.

It's been a few years since I went price shopping for pistons. In that time production options might be possible. They would dramatically lowers the cost. From approaching $1000 to less than $300 Nope you cannot simply look in piston manuals for the Jaguar V12 10.0-1 compression pistons. It's more than that.

frenchyd wrote: In reply to wspohn: If you want a lot of power cheaply, then buy a small block Chevy..However they are like a belly button, everybody's got one. Been there, done that,...next ? Why a V12? Ignore stock power and look at Torque! that little 326 cu. in. motor has more torque than big block V8's do that are 100+ cu in bigger.

I grant you that with the right exhaust system they certainly sound great. My V12 Lambo has a better sound than just about anything else I can think of.

I must demur on the second point, though. The Jag shows very decent torque from low down - up to snuff at 2,000 rpm, but an American V8 equals or betters it with more torque even earlier.

In reply to wspohn:

If you look at the 454 Chevy and compare it to the same year Jaguar V12 you will see the V12 out torque the 454.. I know I was shocked too! The reason is the Jaguar unlike your Lambo or a Ferrari has relatively small ports and valves. It's designed to haul an automatic equipped 4200+ pound car with 4 occupants plus a couple of golf bags. Not so your relatively light Lambo or a Ferrari. You can make a lot of power at High RPM and still be adequate at lower speeds. Plus On a 4 stroke V8 like a 454, only 2 rods will be at 90 degrees at any one time.. A Jaguar with 12 cylinders will have 3 rods at 90 degrees.

In reply to frenchyd: Sorry gentlemen, I'm trying to mark this as a favorite rather than searching for it all the time. I'm sure there are easier ways but it's the only way I can think of for now

frenchyd wrote: Wait, Top gear does that!!! They have a Jaguar V12 block with a Piece of glass on top as a coffee table..

lol ya, if you think a V12 is beautiful and that's why you want one use it like this but then put a real engine in your car.

"I want the largest heaviest most pain in the ass engine that produces as little power as possible with little to no ability to upgrade it"

I think people need to consider the Toyota Century V12, there have been quite a few swaps lately using that one. However it is still expensive pointless garbage to build where there are much more efficient engines to use that also sound great.

In reply to kanaric: The Jaguar XK-E is generally considered the most beautiful car ever made. No less than Enzo Ferrari said so.. So Sir William Lions when he approved the V12 he did it with a lot of credibility behind him.

To make any engine look as well as a Jaguar V12 you'd need to spend $10,000+ or you can swing by nearly any junkyard and pick a rebuild able core for about $500.. Try that with your BMW, Ferrari, Aston Martin, Mercedes Benz, Lamborghini. But for about $500 that's a very impressive neighborhood to be in..

On top of that the pieces in a V12 are extremely high quality. Unlike a Chevy V8 making that sort of power you don't need to replace everything with with special racing stuff.   Not to mention winning LeMans and a whole bunch of other races.. Power and reliability? 750-800 horsepower and reliable enough to Win LeMans

Yes there are lighter more efficient engines around but I'm sorry, they have no visual appeal. Plastic tacky covers, no symmetry, Yes the Jaguar V12 is heavy. So will any V12 near it's size. But that massive Forged Crankshaft is awesome.(It needs to be that massive because it might be called upon to make 750+ horsepower for 24 hours). The Block looks like it just came from a 9000 horsepower Top Fuel dragster after making a 4 second pass

Finally a V12 is soooooo smooth running it feels like an electric motor.

I kept thinking I had deja vu reading this thread then realized its the same dude or dudes saying the same thing over and over and over. What is the hp to weight of that "glorious" v12 anyways?

One last thing, you keep saying it makes more torque than a 454..how much torque does it exactly make? Stock for stock of course

frenchyd wrote: ...To make any engine look as well as a Jaguar V12 you'd need to spend $10,000+ or you can swing by nearly any junkyard and pick a rebuild able core for about $500.. Try that with your BMW...

Last time I checked, granted, which was a while ago, you could in fact get a BMW V12 from a junk yard for $500. It's because no one understands them or wants to work on them. However, with an aftermarket ECU, the sky's the limit.

Jag V12

Benz V12

In reply to chiodos: The V12 weighs about 730 pounds to the 454's 650. As for power and torque the L29 Chevy 454 of 1996-2000 makes 290 horsepower compared to The Jaguar V12 of 1996/97 making 318 horsepower.. Torque is 300 vs 385

The earlier 1975 Jaguar V12 used in both the V12 sedan and the XJS made 282-295 horsepower (depending on destination) compared to Chevy 454 used in the 1975 Chevelle which made only 270 horsepower.
Finally the V12 used in TWR's XJR12 made 750 horsepower while the Lister Storm made 546 horsepower and 580 foot pounds of torque..

In reply to kb58: I agree that since it's so hard to count to 12 (without taking your shoes off) few understand or want to work on them.. However when I checked Car parts.com there were only three BMW V12's listed. One for $2400 and 2 for $1500 However I'm sure that just like a Jaguar V12 junkyards will listen to lower offers.. To be fair, I haven't researched BMW's at all. Are there a number of sources for parts at reasonable prices? As far as aftermarket ECU's while yes they can provide tuning options but it may also be possible to trick a stock ECU.

frenchyd wrote: In reply to kb58: I agree that since it's so hard to count to 12 few understand or want to work on them.. However when I checked Car parts.com there were only three BMW V12's listed. One for $2400 and 2 for $1500 However I'm sure that just like a Jaguar V12 junkyards will listen to lower offers.. To be fair, I haven't researched BMW's at all. Are there a number of sources for parts at reasonable prices? As far as aftermarket ECU's while yes they can provide tuning options but it may also be possible to trick a stock ECU.

Replacement parts for BMW V12s aren't too badly priced and are reasonably available. The engines are 5-5.4 liters, and lighter than the Jag units, and they can be had fairly cheaply. Here's one for $350 that runs:

http://chicago.craigslist.org/wcl/pts/5139811408.html

Or you can get the whole car for $1500-2000 these days.

http://washingtondc.craigslist.org/nva/cto/5119601287.html

http://jerseyshore.craigslist.org/cto/5105295484.html

The E38 750iL is actually a fairly relaible car, at least engine wise, and it's easy to work on if it needs it (though it needs a whole lot less than the V8s in the E38 740i...). And I've seen people use a modern computer tuner to make more power AND get better fuel efficiency at the same time. I've also seen supercharged and turbocharged versions running around.

I love the looks of the Jag V12, especially when cleaned of all the extraneous emissions related crap. But dont' count out the BMW V12 as a good inexpensive project engine, as well.

In reply to Chris_V:

I found that motor too just a couple days ago. What a smoking deal. My challenge car this year is a 1990 750il (5.0l v12), and I got it running and driving for $1100.

As far as ECU goes, there are a few options. 1 - Dinan used to make a 'chipset' for the motor. About 10% gain in power - up to 330 hp. 2 - try to 'trick' the ECU. I dunno what you would do here, but you need to trick 3 computers the same way at the same time. 3 - megasquirt.

M70 (5.0l version) - The compression ratio is 8.8:1, stroke is 75 mm (3.0 in) and bore is 84 mm (3.3 in). So that looks to me like a good head or block shave to bump the compression and higher RPM (short stroke) along with a bit of porting and a good tune could REALLY wake this motor up.

I believe both mclaren and rolls royce used a version of BMWs v12 (m70 and m73) as a basis for their higher end engines. I don't know the extent of the differences.

In reply to frenchyd:

I see you nit picked fabulously! I can do that too, What about in 71 jag made 242-295 hp and only 300ft lbs where a 71 ls6 made 425hp and 525ft lbs.

Dunno where you got your l29 specs but they are 290hp and 410ft lbs seems the 6.0he made 318hp and only 353ft lbs.

Carry on.

rcutclif wrote: In reply to Chris_V: As far as ECU goes, there are a few options. 1 - Dinan used to make a 'chipset' for the motor. About 10% gain in power - up to 330 hp. 2 - try to 'trick' the ECU. I dunno what you would do here, but you need to trick 3 computers the same way at the same time. 3 - megasquirt.

http://www.bimmerforums.com/forum/showthread.php?2092465-Dudmd-M73-tune-rocks!!!

DUDMD in that thread can tune at least the E38 750iL to over 320 WHP (but more importantly, a flatter power band)... and he does it remotely from his shop using an internet connection to your computer connected to your car. Pretty cool.

In reply to Chris_V:

Nice! I'll have to keep that in mind when I move up to an e38 challenge car. ha. I started looking at his personal build thread, found this:

In reply to Chris_V: I often find whole Jaguar V12 cars on Craigslist's for $500 or less and I've purchased running Jaguar V12's engines and transmissions from V8 swappers for as little as $50 when it's time to clean out the garage..

I'm interested in the BMW V12. Can you tell me what does it weigh? Width and length? Is it like a Jaguar capable of 7800 RPM in stock form? Crankshaft Forged etc? What about transmissions? While the Jaguar uses a GM turbo 400 or it's overdrive version the locating dowels make swapping in a manual transmission relatively easy.. A common trans swap is the T5 but you can buy an undrilled aftermarket scattershield and pretty much swap whatever transmission you want.. I have a Tilton scatter shield for a Sienz dog ring

Yeah they only built iirc 69 camaros and 2 vettes with the mythical aluminum zl1 but your right about never seeing any good (or any) big blocks in the yard but I have seen plenty of v12 jags, seems it truely is the grassroots underdog

I think it would be really cool to repower an old boat like a chris craft or something with a polished up jag

In reply to rcutclif: When Jaguar introduced it's fuel injected V12 the computer was extremely basic. Simple to richen it up, timing was still done with a distributor, and of course you could swap injectors around to an astonishing degree.. Newer got more complex but still relatively easy to "trick"

It's not possible with overhead camshafts to do cheap compression increases by shaving the block or heads.. Compression increases come from new pistons.. Time spent with a stock piston in hand, calipers, and a piston spec manual might find inexpensive pistons from a Fiat, Plymouth, or Chevy.. Don't be afraid of changing valve relief or small changes in pin diameters. I bought a $12 flycutter and made a wood holding block to clamp the piston in place on my drill press..

In reply to chiodos: We think alike, future Project# 131 is making a 2/3rd scale unlimited hydro with a Jaguar V12 instead of the Rolls Royce or Allison they all had..

However the later Jaguars (about 1978 OR 79)that used the GM turbo Hydro have locating dowels that make swapping to a manual transmission relatively easy.