The later 6.0 V12? I can get 25 mpg on the highway with it, and I've never been able to get over 12 mpg (imperial gallons, not the tiny US ones!) even with a later injected 460. Every one I have driven was not particularly powerful either.

31 hp/litre out of a late injected engine is a very poor specific power output - considering Jaguars new 4 cylinder does 148 hp/litre!

POLL: You MUST lump your XJS V12
 

When discussing Wankel rotaries, I'm haunted by two dreaded words, "Apex seals." They were never great to begin with, and I can't help but wonder how long they'd last under heavy turbocharging.
If I'd wanted a Mercedes-Benz V12 I would've bought a 600SL. They are indeed plentiful as Hondas around here, slow sellers and with a reputation for fuel economy and reliability that matches contemporary XJSs. Rather over-engineered, IMHO. Likewise the BMW 8-series V12.
I guess I'll stick with continuing to re-engineer what I've already got.

rotaries without turbo are bullet proof(almost).
add any serious boost and they fall apart,yes starting with the Apex's.

a few crankshafts from dead Mazda rotaries, :icon_smash:.

also the Famous rotors themselves, and a hard to find big port rear bearing plate.

a silly custom inlet manifold i was building, before i smarted up, FUTILE effort.

and dont even mention MONEY, they aint cheap, for good parts!

Aston Martin DB9 Rapide Virage Engine 6.0 V12 457HP Only 24050 Miles AM04 Motor | eBay?


because I think it belongs!

:icon_pimp:you know; been thinking what i have with my own Jag V12 , i'll put it up against anything here!!


i wish i could run a computer as well as i build cars,DUH upside down

maybe better

i would go other, Chevy, why? cheap power, 4-5-600 hp are easily achievable with of the shelf parts.

Already lumping my jaguar.. with a cummins

So far I'm the only one to go for the Toyota Century V12. Toyota reliability, from the engine they manufacture for the almost exclusive use of Japan's elite? No-brainer. I'd have been tempted to buy one myself but (a) they're for riding in more than driving, and (b) they are so, so, so goddamn ugly.

.

sounds like a good project, but are they expensive in money??

also who has information about that engine ,Century V12,.

and what if one needs parts for it??:icon_clapclap:

How about a surplus jet engine? From a helicopter some of the smaller ones ought to fit??? The exhaust system would have to be pretty well thought out. LOL Just thinking??? Doesn't necessarily mean it's a viable solution. What was that you said about insanity???

Already been done...

WOW! seen this one at the Hydro boat races , owner estimates 4500hp!!

All I can say is YIKES!!! I wouldn't want to pull up behind him at a stop light!

Second-hand Centurys are like used Jags--can be had for very reasonable costs. As for getting parts.... I'm pretty sure I'd find it easy to get Toyota parts in Japan.... :D

Isn't that engine a double bank 2JZ?

I thought they were only reserved for the Royal Family in the Crown/President models!?

The one for the imperial family is the Toyota Century Royal, I believe. It uses the same engine, however.
There's 135 potential engine donors on this list....
??????????????? | ????????????net?
Hm. Didn't show. That links to a Japanese used car sales aggregator website.

From what I understand, it's 2 of the legendary Supra I6 welded together. So cheap, reliably take lots of boost, affordable and plentiful aftermarket.

Here's a link to a bunch of videos of one in a Porsche 928:

https://rennlist.com/forums/928-foru...-928-a-10.html

[edit] I searched "Century V12" on eBay - normally a handful around the $3k mark.

https://www.ebay.com/sch/i.html?_fro...y+v12&_sacat=0

http://john.bitsurge.net/public/biglist.p2p.gz

most important would be the Toyota ECU that matches that engine!

my choice would be an aftermarket adjustable ECU, SDS,MS,etc.

Stay English, absolutely! It's a Jaguar, after all...
The supercharged AJ16 is an engine that I've always thought of as the one Jaguar should've blessed the XJS with, really. However, the one under the hood on my 2002 XJR is another engine that I would love to have on my XJS, or even a newer supercharged 4.2 version. Of course, we can always go for the supercharged 5.0L...

But then, if the purpose is mostly about sharply increasing power (i.e. acceleration) you don't necessarily have to go and swap engines. On my '94 XJS 4.0 L, I've gone from 7.8 sec 0 to 60 (factory claim) to 5.2 sec 0 to 60 while the OEM engine is still in there. How is this possible? An English nitrous injection system from the Wizards of Nos... The same guy (Trevor, the owner) who installed a very "special" nitrous set up in an old, rusty white V12 XJS and actually beat that bunch of state of the art exotics (1/4 mile) including a Corvette, a Porsche, a Ferrari, an NSX, etc. (YouTube). Mine's currently set at 130 HP over the factory's reported 219 HP for a total of 350 HP. Far less expensive and much easier to install than an engine swap, simple, straightforward and safe and, do I need to mention how immensely fun this is on your XJS? There's something very special (different, brutal?) about the feel of nitrous "pull", even as compared to supercharged power, which is probably why the 350 HP XJS can match the 370 HP XJR at 5.2 sec.

The question always is, how much do you really need this? Well, I would say, only as much as you need either of the other V12's...

Cheers,