Flint,
You are spot on! I like the old ones too but that's the proper sequence for getting one back running despite how good she looks or what your ultimate plans are for the cat. Make sure it runs and then go through Flint's list. You'll be glad that you did. I know all too well how enthusiasm can blind you to overlook major issues until it's too late as in a fire or exorbitant in cost. I have three of them and I learned the hard way.

 

i'm with flint on this one.

just bring lots of money!, i dont think you can put together a Jag V12 cheaply,even doing the labor yourself.

no matter N/A or forced induction.

its more than a matter of 12 pistons and 12 rods, doing the precision machine work ,has to be some one familier with MORE than big V8s,chevy, ford, mopar,etc.

good old american V8s are super simple compared to a Jag v12,(altho jag are simple), but in an entirely different way.

we have seen the epic engine/car builds before on this site,so time will tell. whos got the most money?

 

whoa!! 88 did you say hit it with 40 lbs of boost PLUS a 200 shot of nitrous, do you have any outer space junk collectors, you'll need one to get all the blown up parts back on earth!
sorry its supposed to be funny.

 

Already on that flint! Thanks for the heads up though. ronbros no lol im looking for 15lbs max and a 200 shot basically I want really strong internals. I just dont know where too buy them!!! I build engines for a side Job Im a full time mechanic any engine is an easy build unless its a rotoray engine then its a hard Job. yes I commonly work with american cars but im no stranger too BMW /MERCEDES etc At this point Jaguar is a cake walk. Rotorays I will not touch those are the only ones i turn down never again will one of those cursed things enter my garage :lol:

 

So where can I buy a heavy duty rotating assembly for this car?! It needs too be strong enough too handle at least 1000hp .I over build my engines they last longer . the last one was a 873 hp 350 bf goodwrench block in a f body 2002 firebird anyone want too guess the 1/4 mile time? Ran mid 8's he has since put 53k on it and it runs like a champ even after all the abuse.

 

Paint is no problem as well I only have too buy paint of which ever color i chose too paint it my god father owns a body shop... the car has light surface rist on the bottom of the trunk thats it! it was garaged for years before it sat. only been sitting for 3 years.

 

im curious how much the crank mains will hold. You're going to want copper headgaskets for sure, for the rods, id have your crank ground down to fit a sbc or bbc rod, if you can find a rod /piston combination that would work. then you can get some crower manley or oliver rods that will fit. as long as the crank.isnt cracked if its a 5.3 it should be fine for the power. its ebn40 forged steel.
you might want to look into billet main caps, these are where I see.potential danger.

 

88 nobody has a complete ready to buy heavy duty rotating assembly for jag v12s.

even if there were some,just not enough people to buy and keep you in business for long!

if you havent caught it YET! this is a mostly poor guys car(XJS) ,they are cheap way of getting into GT type sports car.

perspective; both my jags were given to me,just to get them off the property(my garage). that says the value of XJs.

about rotary mazda, when i operated my performance shop in Daytona FL. i was the guy to see, for your rotary builds ,overhauled and built some 500hp turbo engines, those little *******s are bad to the bone,if tuned correctly.

i was/am the type to try anything, i rebuilt lambo Diablo v12s, and did the thing factory said cant be done, align bored the mains after a spun main bearing, that engine uses a 1 piece main girdle,, it was cheaper to do than(after pricing new block) at $21,000. dollars.

but that nothing compared to the king of the hit list, a 1934 Duesenberg block, some machine work, owner said(after i finished) if the block was damaged beyond repair, a replacement was $150,000. ,thats used unmachined, bare block. if you could actually find one.

that gave me something to think about! NAH! not my style!

that was before internet, and yes, that was a different time.

something i notice lately, the new young guns, spend a few months researching the net,
but have no actual HANDS on experience, say like building real hi-output engine, and havent had any practice in the art of tuning.

you mention 1000hp, how far off A/F ratio or ignition timing degrees, would it take to hurt the engine?

 

The engibe cant be off at all or it will be singing its death tune! no one majes cranks for these ... oh well ill get one built later iknow parts for these are not marketd much theres really no demand for them. im just wondering where others have gotten theyre parts from

 

Calvin thanks for the info on the crank! i managed too get my hands on two turbos from volvos t5's . no idea how im going too hook them up still might do a procharger... oil pump handle the rpms? im looking for an 8k/9k redline i found a 5spped kit for 600 so thats in the works for a t56. Has anyone dared too build theyre own intake for a v12? Done it on a 350 but not a Jaguar lol

 

I guess I've become an old fart. I used to build sbc's and and the old big block Pontiacs, and I was the engine rebuilder at the garage I worked at before I switched careers.
Now I try to squeeze out as much performance as I can without major modifications.

 

I know this doesn't sit well with everyone, but I wanted a faster XJ6 and this is the best dollar for dollar mod that I could think of:



Performance parts are inexpensive (relative to building a Jag V12) and there is a huge body of experience and information at your fingertips. Yea, it's not a Jag V12, but that's both a bad thing and a good thing. Just a thought!

 

nothing wrong with an LS series engine,especially turbod, BUT it aint a V12, 12cylinders is about the talk not the walk, and the sound thru a nice exhaust is encredible, they dont rumble they whine!

check my garage, Buick grand national, after blowing up two turbo engines, in went an LS2 6.0L with a 4L80E trans. now its a real fast and DEPENDABLE car.

course usual brake and suspension upgrades,

but my jag gets more looks than the buick at car shows, owning these old cars is about (mine is bigger than yours) yaya. or something to that effect.

 

88 good idea ,a turbo on each bank, and those Volvo turbs. would do just fine,size close enough for Gv. work. they could be mounted remote at the back of car,check;STS turbo systems,lots of ideas, very interesting stuff, a quick pic of my opel with a remote turbo.

with a reasonable turbo system, performance would be respectable! using a running ,stock V12, flat or HE. the key would be tuning, for a positive pressure in the inlet manifold instead of a vacuum. the Jag V12 dont breath well after 5500-6500 rpm, and the HE drops off earlier than that around 5000.
but with a turbo system forcing air in they just may surprise everyone!

but Yikes; 8-9,000 rpm, nope aint gonna happen,(more than once or twice).

and manifolds; just about everything has been tried, tho nothing seems better than ported factory types, with big TBs.

altho i kinda favor the long tapered log type with the TB mounted on the end, if you are serious a long runner system would be advantage.

but if i were gonna do it over(after getting 20 more yrs knowledge), i would have a totally different plan. out of the box..
in this modern tech world, cubes are not the complete answer.

back in the F1 turbo era, Honda had a 1.5L V6, making over 1100hp, without the turbo it made around 250hp. something to think about.

 

8 or 9 is doable, after talking to chad I realized I've been underestimating these things. there is a specific way to port the he head to make 450+hp. the factory eengine will hit 8ish on stock valve springs, so upgrading them is a must. and id go lightweight rods and forged pistons. I've built 426 hemis that run 8.5k and make 800+hp. (I've got a little more experience than I let ron know, Shhhhhh). I did the 5 speed swap. trouble is t56 doesnt line up with a 5 speed bell. its to.short of an imput shaft. realized thst after I picked up my t56. if it were me! id go automatic with a select shifter or electronic paddleshifter. there is a reason buick never put a five speed in thr grandnational. and the turbo firebird. and after we bolted a 3.8turbo to an m22 in a 66 chevelle I understand why. turbo lag like a mother....

 

The stock 5.3 crank is an EN16T forging along with forged rods, the pistons are the weakest link. Gary Walker built the first XJS TT many years ago and was reported to have nearly 1000hp on the stock crank.

There are a couple of twin turbo XJS's in Australia. The one I am familiar with is a 5.3L heavily modified and makes around 550RWHP but enough torque to break 2 Jerico heavy duty racing boxes.

 

I was talking to Norman from the E type factory here in Melbourne. He was telling me the HE heads can be machined to de-shroud the valves and make decent HP. Unlike the Chev the intake valve on the HE V12 has a fair amount of room between it and the cylinder wall, it is the exhaust valve that is close. He would not be specific but from what I gathered the HE chambers were reprofiled to improve flow.

 

chad bolles said the key isn't to deshroud the valve, its to improve the flow of the exhaust port. chad only uses he running 16:1 compression. and he profiles back.of the exhaust port to have a smooth transition. this helps him make 450+ on s 6l and a lot more larger blocks

 

Wow 16:1 compression? That's incredible... almost unbelievable unless he's running some sort of special fuel like E85, or race gas... and even then...

 

YES! 450 hp may be doable N/A,, and 550-600 turbod may be doable, but the stories of 700-1000hp JAG v12, may be just a story.

and i think i mentioned this before, controlling heat in the engine is key to longevity in any engine, a marine/boat engine has an OCEAN of cool water to work with, so any cooling probs would be the mechanic/technicion.
marine can run more compression and more timing, and you can be rest assured those 1000hp turbo engines dont last long, or what fuel they used.

and gosh only knows what those heads were, some place in my travels, it seems Grp44 got some heads from AUS. HMM interesting. Bob Tullius tried to get heads from Jag/TWR,they wouldnt give them to him, so ended up having head castings done in California, and machining and flow benching done there also.

thats those hi D port heads,(i would love to get my hands on a set), in usable condition.