Ferrari V12 vs Jag V12 vs BMW V12

Everybody extoles the wonderful virtues of the Ferrari V12s and their signature exhaust sound and performance like no others. But Jaguar and BMW have had V12s in their various production cars. How come you don't hear much about those other V12s and their usage in hot rods and custom cars? Jaguars and BMWs are much more common, so the chances of latching onto a V12 out of a wrecked car are much higher. But you just don't hear much about them. It would seem to me that a Jag or BMW V12 would make a great hot rod engine or dare I say, a replacement for a long lost Ferrari V12. What's up?

 

i've always heard that the jag twelves were notoriously unreliable.

i've generally heard that the bmw twelves are tremendously great when they work, but when something goes wrong they are a bear (expensive, time consuming, etc.).

i guess the owners don't expect that sort of thing, whereas we've been conditioned to expect to get bludgeouned with a credit card processing machine whenever we walk into a ferrari shop

doody.

 

The Jag v12 is an amazing sounding motor with the propper exahust on it. Trouble is the are boat anchors. very troublesome with head gaskets and oil leaks. The only 12 I would consider is the singal over head cam version of the 60's. These ones seem to be very good. I have a few xke's that come into the shop and I love them. A little tight to work on but not too bad. Say away from the one in the XJS series cars..just junk is all that motor is. Clean it up and make a coffe table out of it.

BMW 12's I can't really comment on..I don't have too much experiance with them except for in the 850ci cars which were junk. I did hear that the early ones had problem with the block twisting and cracking. But I may be confusing it with another car,or BMW engine.

M-Benz make a good 12 cylinder..very strong..but agin bad for oil leaks and timing chains.

anybody else?

 

Please correct me if I'm wrong, but Jaguar didn't make a 12 Cylinder
motor until 1970 or 1971 I believe.
The Jaguar 12 is a nice smooth running engine, but nothing like the balls to the walls Ferrari 12.
Bill

 

OOps....sorry..late sixies or 70's I should have said..thank for the correction

Tom

 

Tom,
I have a 91 XJS 12 cylinder that I purchased new, my wife drives it, and we really have had no malor problems with it. Why do you say the motor is junk?
WilliamR

 

Jag V12's are a pretty solid motor. Had a few of them in XJS's and put over 100k on them. Little oil leeks but no different than the Fcar V12's. Later XJS's had more HP and with the right after market stuff they made good HP. On of the applications that they were used for is 4/5's scale airplanes. They used the V12's in the P51 Mustangs . Good fit and performance and made good HP.

 

Please don't take my post the wrong way.

But from the number of cars I have seen, I don't think I have seen one with out an oil leak or a timing chain slapping around(o.k. maybe 1 or 2).
They do have a big problem with the head gaskets popping,and to service this, the engine is best to be removed. They really don't put out the power that one expects from a 12,but it is a very smooth power. maintaince wise they are a nightmare for the mechanic. I will not work on a Jag such as your wifes car. Everytime one would come in i would loose my shirt on labour,because the job always took twice as long then expected. Never mind I would have to go out and buy more bandaids. The Jag dealer next to my shop will not touch an older V12 Jag for the reasons stated above.

Congrats to you and your wife on enjoying your car. You must be one of the very few who got a good one. To all the rest, god be with you.

Tom

 

Got 30yrs working with jags and owned 5 of them. I always bought them because they had poor resale and no one wanted to work on them. I found them a lot of fun and never had any major problems. As far as working on them it was easier than working on my 308 and the parts were cheaper. So I drive the Jag as my daily work car and take the 308 out on weekends. Good combo for me.

 

I've had a BMW 850i for about 10 years now, with a six speed, and its a marvelous engine. I've got over 120K miles on it, and besides oil and filters, drive belts and hoses I've changed the plugs twice and replaced a faulty thermostat. It starts instantly, makes good power, and doesn't burn any oil.

Some folks have a bad opinion of 850s because of the 840s. The 840s used an eight cylinder engine with a nikasyl block which wore out cylinder bores because of too much sulpher in US gas. BMW replaced most of them. The V12, both the M50 and the M70 engines had no such problem. There are a lot of electronics in the 850, which was leading edge for its time. Many folks feel uncomfortable with them because of the electronics. The Electronics Manual is twice as thick as the Mechanical Shop Manual.

But don't feel bad, most other BMW afficionadoes hate the car as well, and ignore it. There is a small, but active web community of 850 (e31) owners, and most of them wouldn't give up their car for anything. It is a very comfortable high speed highway cruiser. I regularly make it from my house to Denver (1000 miles) or to Spokane (900 miles) or back in one shot)

The issue with the engine is that it is a very conservative design. Single overhead camshaft and very restrictive breathing (small 2-valve heads) The ignition cuts out at about 6000 RPM, so there is none of that 7500 RPM scream you get from a Ferrari V12. Lots of low-end torque. Some owners have tried to duplicate the Ferrari V12 sound - I've heard one with open pipes that sounded pretty close. The problem is that the power DECREASED without the factory exhaust!

I might point out that the MvLaren M1 used this basic engine, which was heavily breathed upon, and it is no slouch.

 

i'd take the BMW M V12 in the McLaren

 

had a 94 xjs V12 convert several years ago, no problems

 

Does anyone have any opinions on the Aston Martin V12? I've heard its basically two Ford V6's, they're kinda new too so I guess reliability shouldn't be an issue, yet. I was just wondering what some of the mechanics here would say for it, to work on and power possibility etc, compared with some of the other V12's you've talked about?

 

is the major diff between jag bmw benz v12 vs fcar lcar v12 is that the italian v12s use a flat crank and are designed to rev till 7500 8000 rpm ???????

 

The OP started a comparison to Jag and BMW. What about Aston Martin? I would like to hear comments from others who have experience on those legendary motors.

Steve

 

The Mercedes V-12 engine, especially the AMG tuned engine is a beast. My next door neighbor has one (regular V-12) and he has about 90K miles on it. He loves it.

 

V12 Aston runs great(most of the time) Tight to work on-changing the coils which it burns should be simple but is a PITA. Doesnt make a ferrari sound and I havent tried a different exhaust. If a fuel pump goes you run one one straigt six. Mine has 75,000 miles-no leaks or oil burning. I also have a ferrari 12. Other owners comments?

 

Jag V-12's were not a big time robust engine - but were really smooth... I've seen several however that were tuned up and sound great - used in kit car mods.... one in a Ultima chassis - with FI and big bundle of snake like exhaust ... actually sounded aswome

another in an outlaw 71 XKE - kind of like an eagle type - had a V-12 -with side draughed Del orto carbs? this was at Goodwood 3 years ago.. just was a cool - mean looking car ... it had side pipes which were painted white against dark greenish blue paint... it was really nice. It had European plates - I think from Belguim...

 

I think the BMW and Jaguar suffer from depreciation issues. Some model Ferraris are the same. The market value drops and people are disinclined to spend real money on maintenance and repairs. If not careful a person could pick up an older 750 BMW that runs great but need many thousands in repairs. My brother was a BMW tech for many years. A customer had just picked up a 750 and brought it in for oil leaks. The repair estimate was $11,000. At this time he was at an independant and it was the cheapest estimate this fellow received. I guess he loved the car enough, after a bit of time he started getting the work done but not all at once.

I've been fantasizing about having a V12 collection and starting with the BMW and Jag, just have them on stands as art. I've seen an 750 BMW as cheap as $1500.00.

 

Those 850 BMW's are still one of the prettiest BMW's ever built. My brother has one and it has been flawless. He is in the "I will never sell it" camp. The only problem I find with the 850 is the engine does not feel special like the 550 Ferrari motors (I know those best) and the weight of the car kills the road feel. Ferrari Maranello motors have the right noises yet silky smooth power delivery and endless torque feeling like a big brute just powerlifting in one clean stroke. A simple phrase might be, "dang we are there already." The V8 Ferrari motors have the sound and cool vibrations through the chassis that make you feel like you are going faster but always seem like they are starving for air.

 

If its good enough for Pagani, Its good enough for me..AMG V-12

built in Italy they could have chose F car Engine, makes you wonder which would have done better??

still holds Top Gears # 1 spot of lap times by the Stig!


http://www.autoblog.com/2013/01/28/pagani-huayra-sets-new-top-gear-test-track-record-in-season-prem/


Doesnt Rolls Royce run will the BMW V 12
http://ask.cars.com/2010/10/does-bmw-own-rolls-royce.html

 

I always heard the Jag V12 was big and heavy, not too much power. I imagine you would need a different crank and a lot of head work to really make a sporty motor out of it.

The BMW did not make a lot of power and was a slow rever. the 840 witht he V8 was almost as quick and a more snappy driver.

Baily edwards in South Africa uses the BMW 12 in their P4 replicas, so someone has done the work to make performance motors out of them, and yeah you can get them at junkyards cheap..

As far as I know the engine from the Maca F1 while built by BMW has nothign in common save being a V12 with the regular BMW 12.

Yeah the merc 12 seems great.

But you can buy any manner of ferrari 12 motors relatively inexpensively, so why bother with somemthing different. I think 550 maranello motors are great, and the ones from the 599 are pretty close to an enzo motor.

Also is not the motor from the 400I oretty much the same as a daytona, just head and cam differences?

Basicaly a motor like the Jag or BMw was setup for a big road car, they have heavy cranks and flywheels, the internals are not designed to reall rev or hold revs, the heads and cams are more for low end torque. So what you get is a block.

Aston V12s should be pretty good too.

 

I made my first post on this thread nine years ago (#10). I still have my 850i and wouldn't change anything I said. I still drive the car on my summer Denver runs, it still runs fine. I follow the 850i (E31) threads on another website, and over the years there have been many attempts to make more HP out of this engine - chips, nitrous oxide injection (don't even think about it), superchargers, turbos, etc. The best results seem to have come from forced induction and chipset changes. According to KBB 850i's are worth under $7K these days, so you could buy the whole car for less than an annual on a 550. Getting it to run well and all the electrics to work is another matter.

 

Could they have? Ferrari isn't in the business of selling their engines (especially to a competitor), where BMW and Merc are as they don't have direct competition with Pagani (or McLaren).

 

Have a '72 V12 XKE convert and the Testarossa. I last tuned the XKE 2 years ago....it starts every time after sitting a month at a time. GREAT car...no better one than a gorgeous V12 XKE conv to cruise down El Paseo in Palm Desert on a beautiful night. The problem with the car, is NOT the car. It is the owners that take them to idiots to be serviced. You cannot take these to your local Jag dealer..period.

And of course the TR is just what it is, a brute like no other!
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