Jaguar V12.

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hallucinogen_99, Feb 16, 12:27am
Hi,

Has anyone on this board had any experience with the Jaguar V12. Would be keen to know of your experiences & opinions on this engine.

Cheers.

thejazzpianoma, Feb 16, 12:33am
Not the twelve but have experience with the 6 which is much the same technology. What age are you looking at!
Assuming the same deal as the 6 getting a later one with hardened valve seats is a good place to start. (or one thats been upgraded)
Even the 6 can be pricey to rebuild and some can need major work as early as 160'000km from what I have seen.

Also. be aware that the inboard brakes on those puppys can be expensive to get sorted.

What car is it in, what are you using it for and whats your budget!

thejazzpianoma, Feb 16, 12:35am
LOL, two gears is all they need! Some of the auto's would usually take off in 2nd by design (unless on a hill) so that's effectively all you had too!

Even the 6 is thirsty. but like you say. what a car!

thejazzpianoma, Feb 16, 12:38am
BTW, I think I know why they went for the smaller grill on the Series two XJ6, ours would have the worrying habit of popping the bonnet open at 120mph.

Then of course you are faced with the issue of slowing down and having the rest of your view taken away as it rises further with the drop in speed. or maintaining speed while you wind the window down and stick your head out.

Good times!

hallucinogen_99, Feb 16, 12:38am
I'm looking at getting a 1988-1991 XJS V12. The engine bay looks a nightmare and I know they are known for overheating with devastating results.

Is there anybody who was good knowledge of the V12 engines other than the main dealers! Has anyone here ever had to get engine work done on a V12!

hallucinogen_99, Feb 16, 12:42am
Also, can you fit an overdrive to the 3 speed GM400!

afer_daily, Feb 16, 12:44am
you could allways do what guy did on TM and build a trike.

richardmayes, Feb 16, 12:45am
Can't be any worse than getting work done on two overhead-cam straight sixes at the same time.!

A sales rep I once worked with used to own a series 3 E-Type, he reckoned the easiest way to do a u-turn in it was to just stab the throttle briefly.

thejazzpianoma, Feb 16, 12:46am
I know of a guy in Katikati who rebuilds them for a sensible price if you have major problems. Havn't used him personally so can't comment on workmanship but might be worth checking out further.

I would own ita while before pursuing the O/D. I am not sure its going to save you much on gas or help with road noise and its not like you will need more top end for road use.

thejazzpianoma, Feb 16, 12:49am
I don't think Jaguars 6 was really much better (although I heard comparativegood things about the smaller 3.6 litre 6 with manual gearbox combo)

U turns in our Alfa require the same technique. I am sure the Police will understand completely.

EDIT, meant to say that at that age group you should be sweet with the hardened vale seats OP.

pfemstn, Feb 16, 12:55am
They are getting old now so beware of leaking fuel hoses, particularly to the injectors, they are reknown for catching on fire! oil leaks also a problem! would rather work on the six any day! just try replacing the belts on a 12! not a 5 min job, same with changing the plugs! allow half a day!

hutchk, Feb 16, 1:29am
Les Parkinson ('Dr. Parky') out Kumeu way knows Jags inside out and has a manual V12 XJ-S (among others) which I've had the pleasure of a blat in. Strongly suggest you have Les check the car over prior to purchase - he charges reasonable rates and he's a bloody nice bloke.

elect70, Feb 16, 1:30am
Make sure its the later HE headmodel , like all jags need a lot of TLCrealy need to have mechanical skills& workshop manualotherwise cost$$$ to take it togarage for everyfault , i had the use of aWalkinshawXJSwhile mate was on his big OEfor 2 years . Nice car . V12thirsty ,though the HEMay head models better .They say they will becomecolectable .

thejazzpianoma, Feb 16, 1:42am
Will definitely be HE being 88-91 so no worries there OP.

rob_man, Feb 16, 3:33am
There was a school of thought that they were a scaled down Merlin V12 with mods.
Any truth to that!

cossy5, Feb 16, 3:57am
Had a XJS 3.6 manual for a while, Great car! service cost very high though.
Once asked a V12 owner what fuel was like around town! = 14mpg and on the open road! =14mpg. XJS V12 owner in Lyttleton (steep hills) had used aftermarket pads in the handbrake, result, weight of the car ripped the lining off the backing plates, bye bye car.

ladaspeed, Feb 16, 3:58am
Always cracked me up that the HE stands for "High Efficiency" so 7 MPG rather that 5.!

joanie32, Feb 16, 4:11am
I run one in my scratchbuilt car (see my profile pic). Minehas 6 webbers, trick cam, custom exhaust etc. Not a scary motor to work on, just a lot of junk to work around in a normal jag. Look onjaglovers website.

foxdonut, Feb 16, 4:35am
There was a TWR car on ebay.com.au that had a couple of small turbo's strung on and it was making an easy 500 horse from memory. Like most Jag engines it probably started its life as a gun carriage engine in the 1910s so it'll likely be hard to pop.

I guess it pays to remember that they were a top range car when they came out, the cost of ongoing ownership will probably reflect it.

rob_man, Feb 16, 4:38am
Only ever owned one Jag myself, a 1959 MkI which I put a 327 into. Went good.

wrong2, Feb 16, 4:47am
one of my favourite bathurst clips on youtube

http://www.youtube.com/watch!v=M9I7GWllPFY

chris_051, Feb 16, 5:50am
I like these 1980s Euro luxury coupes, but have you also looked at the Mercedes 560SEC or Porsche 928 as an alternative or is your heart set on an XJS!. I used to have a 560SEC, 300hp, 4spd auto, would blow the doors off anything else for the time that wasn't a high end sports/super car. Awesome cars I'd suggest you'd take one for a drive before laying the hard earned down for the jag as this was an era when Mercedes were designed and built to a standard not a budget.

flockton55, Feb 16, 7:44am
Had a nice long post and just lost it.Grrr.
I've had a 1984 XJ12 since 1993, and have done all the work and repairs on it myself.
Short answer: Forget all the scary stories above.
Go to http://www.jag-lovers.org/xj-s/book/and download this free book. About 700 pages of the best info on XJS tips, tricks, answers and info.Compiled over many years from the XJS forums on Jag-Lovers.
I'm happy to help with any info or advice if you want it.Forget Mercedes, you want a car with some Soul.

rob_man, Feb 16, 9:17am
Yeah, bloody impressive eh! Something about seeing a very strong car four wheel drifting at high speeds, you don't get much of that nowadays.

flockton55, Feb 16, 10:14am
The two classic Jaguar engines were the XK and the V12. The XK came out in the Mk7 and XK120 about 1950, and was used and developed until 1985.The V12 was first in the Series 3 E-Type, but was used in the XJ12 from 1972 to 1996 and the XJ-S from 1975 until 1996.
Both of these engines were regarded as being at the forefront of design when they were introduced.The inherent soundness of their design is evident from their longevity.So which Jag engine were you thinking of from 1910!Hmm!The V12 has been pushed out to about 7 litres in a road car, and even bigger for aircraft and power boats.