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DILYSI Dave SuperDork
7/3/09 10:59 a.m.

I know that they are generally hampered with all sorts of carburated BS, or Lucas BS, or 70's emissions BS, or if you get real lucky - all three.

That said, is there potential? Would forged rods, decent headwork and a megasquirt be a 700HP badass, or a POS british time bomb?

fastEddie Dork
7/3/09 11:13 a.m.

I don't know but they seem popular "affordable semi-exotic" engine swap candidates.

Good HAMB thread - http://www.jalopyjournal.com/forum/showthread.php?t=359073

jpaturzo New Reader
7/3/09 12:46 p.m.

My job here is done.

Jensenman SuperDork
7/3/09 1:24 p.m.

Wonderful engines, exotic sound. A little long in the tooth, though. Like an acquaintance said, it takes up a lot of cubic feet per horsepower. I am honestly not seeing 700HP with any sort of reliability.

Salanis SuperDork
7/3/09 2:00 p.m.

Because this one goes to...

MrJoshua SuperDork
7/3/09 2:27 p.m.

If you can dig up that miata.net swap thread there is lots of good info there. Something weird about the combustion chamber is all I remember. (think it allowed some stupidly high compression though)

fastEddie Dork
7/3/09 3:20 p.m.

See the HAMB link above for some good basic V12 info - old style heads vs. HE heads, etc.

Oh yeah...

M030 Reader
7/3/09 4:37 p.m.

This guy gets 600hp out of them!


procainestart Dork
7/3/09 5:52 p.m.

Check it:



alex HalfDork
7/3/09 6:02 p.m.

Thank you, Dave. It takes a member with some clout to get serious answers to this question.

For the longest time (okay, about a month or two, but I have a very short automotive attention span), I have thought of picking up a running XJS, pulling the V12, stripping it down to the absolute essentials (both the motor and the car), stuffing my bog block Ford V8 in the Jag, then using the Jag V12 in my Model A.

Y'know, just 'cause.

M030 Reader
7/3/09 8:54 p.m.

In reply to alex:

Yesss!!!!!! That would be one bad-ass Model A!!!

Jensenman SuperDork
7/3/09 9:16 p.m.

Of course there was the XJ13's 4 cam version:

Just imagine that thing singing about 10" behind your head. Yowza. Sign me UP.

Schmidlap Reader
7/3/09 10:24 p.m.

Sorry, I've got no tech (aside from suggesting you research TWR to see what kind of power they were getting), but if you need encouragement:




On edit: I did some research and TWR was supposedly getting about 750hp out of a 7.4L V12 (bored and stroked) in the XJR12 racers (Lemans prototype sports cars) - no idea if these were turbo or NA, though at 7.4L I'd guess they were NA. Lister put a 7L Jag V12 into some modified XJS' in the early 90's and were getting about 550hp.

Also, Jagweb/AJ6 Engineeiring has some info on upgrades: http://www.jagweb.com/aj6eng/v12_performance.html


Andy Reid
Andy Reid Auction Editor
7/8/09 1:04 p.m.

The jag V12 is a very good engine generally thought to be as good or better than the Ferrari V12 by many. The engines have tons of potential and are not inherently unreliable.

MrJoshua SuperDork
7/8/09 1:56 p.m.

You guys suck! Off to crazedlist.

Stealthtercel New Reader
7/8/09 3:58 p.m.

David E. Davis, Jr., once said that everybody who cares about driving should drive (or he may have said "own") a V12 at least once. Having driven a Jaguar Series 3 XJ12, I agree they're special... but one of the links in this thread tells me that, faced with the considerable cooling demands of the beast, Jaguar split the radiator 1/3 -- 2/3 to cover the two banks of cylinders... and then put the temp gauge on the 2/3 side! If this is true, the logic escapes me, and the expression "ticking time bomb" comes to mind.

Dr. Hess
Dr. Hess SuperDork
7/8/09 4:09 p.m.

A guy in my English car club used to own a English car repair shop in NJ. He got to the point where he refused to work on Jag V12's anymore. He'd fix them, they'd come back for something else or the same thing broken again. Put a new ignition module on them, thoughtfully mounted somewhere really hot, and it would go bad, leaving the owner stranded on the side of the road. They'd call him, he'd come with his trailer to pick it up, they're gone because when it cooled off it started working again. Pre-cell phone days.

I also recall a cooling hose that runs through the block.

poopshovel MegaDork
7/8/09 4:19 p.m.

Dave - I've got a better idea: Why don't you come over to my house this weekend and we'll light stacks of $100 bills on fire?

ronbros New Reader
7/8/09 6:22 p.m.

here is my Jag with a modded V12, you should hear a V12 at 7000rpm,open exhaust.

ques. how do i put an attachment or pic on this site, guidelines dont say much

alex HalfDork
7/8/09 10:37 p.m.

In reply to ronbros:

Above the smileys (above the box where you type your post) is a row of icons. The third from the left is for a hyperlink, the fifth is to link to a photo.

Hope that helps, 'cause I definitely want to see more about your Jag.

Hasbro HalfDork
7/9/09 12:47 a.m.

While we're on the subject, If I have a favorite car, I suppose it is the XJ13. Actually a redesigned kit car is prettier but close enough.

Do not watch this video if you plan on having sex tonight - or maybe you should watch if planning on having sex tonight... http://www.youtube.com/watch?v=MxqfVLxx55Q

Edit: Watched it again. I'm good.

ignorant SuperDork
7/9/09 4:25 a.m.
Andy Reid wrote: The engines have tons of potential and are not inherently unreliable.

this is what i hear from my british friends. Its the accessories and electrics that will drive you mad.

ronbros New Reader
7/13/09 6:14 p.m.

Frustrated!!! ronbros here! pix in thread!! what is a URL??? gimme a break, im 75 yrs old computors are totlaly an alien instrument, Ques; why is it so complcated to put image here, most sites i go to you just click Browse?. and my pix come up and i enter them!

stuck In Chicago, and only communiction is this damn key board, which i have no idea how it works. Engines i know somethin about,but computors???

John Brown
John Brown SuperDork
7/13/09 6:35 p.m.

ronbros, are the pictures on your computer or are they on a website already? If they are on your computer then you need to upload them to a photo server (picassa is free through google) If you do not have a google account, they are free and I can send you an "invite" to set one up.

ronbros New Reader
7/14/09 5:19 p.m.

pix are in my computor,MY PICTURES, and i have a google account, or google chrome, will that help?

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