Also, although fi and na may have the same numbers of hp/tq the power curves are way way different. Would you rather have a wild cammed 426hemi making 800hp500 or a mitsubishi evo motor making 800hp?

 

Absolutely. Also, can we dispense with this "turbo halfway down each of the exhaust pipes" myth. Turbo lag makes all road cars undriveable, I believe, and the further the turbo is from the inlet valves, the worse the lag will be, that is for sure.

Back to the subject at hand. Here is a 6.0 crank for sale in the UK, bidding currently at about 75 USD.

http://www.ebay.co.uk/itm/JAGUAR-V12...item2c6c152262

The guy has other bits too, I think. Worth a chat or an email? Someone on the list might be coming to the land of the free and bring it, or even postage might not be too bad.

Greg

 

I think a 7.0L V12 is going to cost to $$$ build 93.5mm bore and 84mm stroke will give you 6.9L. The only way to do it is a 6.0L crank and offset grind to a small journal chev rod without going to the welding option. When offset grinding you need to take into account grinding the journal for roundness. SO you will not get the full 0.300thou stroke you lose at least 0.020-0.040 (depending on crank condition it could be more) in the roundness grinding. Also the crank will need to be re-hardened and the Jag cranks were nitrided as well.

That could be a good deal Greg had suggested. Just be aware that the 6.0L crank is different than the 5.3L. Depending on the model of 5.3 the differences are:
- Lip seal instead of rope (5.3's went to lip seal about 1989). Different at the flywheel end
- Snout is different from all 5.3's will require a new HB.
- Bearings are different (tighter tolerance) but 5.3 bearings can be used.

I know where there is a 6.0L engine. In my shed....sorry

 

I am looking atthe 84mm billet crank. And liners. I was thinking of using 5.3 ls pistons. I am going to talk to an engine builder later this weekend.about what will work.

 

if cubic inches what you after,, just buy a GM crate motor 572",, that 9.4L of pure torque, and still rev to 7000rpm.
thats right nine point four liters, and the best heads in the business, all the work has been done, best of parts. make 750-800 all day long.

a recent interview with Grp.44 was Jag V12 at 7.0L was not very reliable, they blew some of them up,and expensive to build, thet tried a lot of chevy stuff also.

but i know 572 aint got 12 cylinders! heck you could bore it to a NICE round 10L.

in the long run i'm guessing it would be cheaper in the end also.

 

well the 12 cylinder is my thing. i want to build an epic jag v12 to go with my 5 speed swap and all my work on the suspension. but anyone can throw a BBC into a jaguar. it takes some real skill to build a massive jaguar v12.

 

while you are dreamin, check the intake system on this old Jag V12.

its all made of Magnesium, with 12 TBs, and slide throotle plates, electronic FI.
notice the long tapered trumpets, i would say a kool look, nice headers also.

one of those Gp44 engines came up on ebay, 7.0L complete with fuel system, HB to flywheel. starter&alternator.

the whole package sold for $4500.bucks. Yes; sometimes i aint the brightest light bulb, i didnt bid.

i'm told that the FI system is worth $5000-$10,000. alone.

 

is that a group c car? im told the crank im bying is an 88mm stroke machined for a group c car.

 

YES that is a Group C car, also called IMSA GTP car.

wow! crank your gettin has 18mm more stroke than a 5.3, makin that thing fit, ought to be interesting.

makin the whole thing run right, should be an exercise in knowledge, whats your experience level?

 

There has been a crank @ 88mm + flywheel for sale in the UK for a coiple of years now, Guy has cut it +20 and not hardened it. Good luck! I know of no others about so this must be the one. To get the 7.4 you will need special 84mm pistons, this will require the block bored and special liners, actually very special liners as they will need to protrude from the face of the block! The originals had the 2.1 BE and .927 pin, ther is not enough room for this set up on a standard deck height so the very few TWR engines built like this has special heads with liner recesses to allow the extra long liners and the pistons to go into the heads so making it all work. Good luck best forget this right now. Go with what is easy. Further problems with a Group C crank are the rear of the crank is a smaller diameter, it will cost you lots to get this sorted, if you ever did get serious power you will split the cast caps, you need custom steel ones to hold the bottom end together, the cross drilled crank requires more oil flow, so you need to sort that to + scraper plates much bigger valves and ports + cams to make the whole jobby work. Inlets and exhaust will have to be sorted etc etc. Maybe just buy a 2nd hand 6L and drop it in.

 

finally ,some one who has real knowledge of how to build a jag V12 7+L engine.

and a factory 6L with twin turbs, great way to go!

 

Calvin there is no displacement for replacement is true but with the way these heads flow the best way too go is boost. Im into all motor myself but unless your buying custom heads that will flow the way the motor needs too make a subtancial amount of power over stock . i think youll be looking at 500hp . after that your hitting its limits . I build hypo flatheads for everything from race mowers too hotrods flow is go in any situation id stay on the path your going but get dish pistons concave valves and either turbos or a procharger (dual maybe?!) Ive been looking at the numbers and what would work best for my 5.3 build two prochargers would be great but pricey and takes up space. two turbos?! Then theres turbo lag but theres ways around that . Simple fact is more fuel more air more bang!

 

Cal

I tend to agree look at Lister they only made 500hp from 7.0L so they twin supercharged the 7.0 to get 600hp.

Forget rear mounted turbos unless you run the intake back through the car, no room underneath.

I have been looking at boost and there is room for a procharger/vortech if you remove the PS pump. Use a Toyota MR2 electric PS pump and the supercharger should fit there.

 

Maybe this is being done back to front here.
1st consider and decide what you hope to achieve. Then decide how much you can afford to put into the project. The rest will then fall together of what is possible for the price. Serious power increases require serious money. (strumming my fingers wondering when my 2 sets of titanium valves will arrive) As for the Lister engines, they where generally horrible, slung together with used parts, even the bearings! Std heads or if you where lucky slightly bigger valves with re-profiled cams and a basic std injection system + starter injector (mister) on full load. Nasty. Most blew before doing 4K miles. I know as I have rebuilt a few inc twin supercharger models. On the last supercharger one I got boxes of bits because 2 previous experts had given up on it. To rectify the 'experts' work I had to fit another crank, another pair of heads and another set of rods, didnt like the new pistons but used them anyway, hey ho. These are not the run of the mill v8 nor are parts easily available for them.
I am not aware of any real expert on V12's in the USA, on only one died last year, RIP Lanky.

 

I don't think it's all about skill - more about money. Unless you're making everything yourself, you're buying the skill! Looking at it by dollars per horsepower, the Jag V12 seems like a pricey platform.

I hate to dissuade you, but I want to introduce two similarly-priced options that make my toes tingle:

1) Aston Martin V12 - 400hp, 400tq - Keepin' it British, sexy engine, similar to the Jag V12:
2002 Aston Martin DB7 Vantage Complete Pull Out Engine V12 Motor 9 000 Miles | eBay

2) BMW V10 - 500hp - Born to go. There's your 500hp! Get it tuned, make some headers, and add another 50hp.
06 07 08 09 10 BMW M5 M6 S85 V10 Engine Motor Complete 30K Miles Vin Available | eBay

I don't mean to stir the pot, but those are really neat engines - and just the tip of the iceberg! There are just so many options for cool engines out there - many with the technology you are trying to recreate already developed by the manufacturers through millions of dollars of research.

 

RIP Lanky!!

i knew lanky personally, he had a lot to do with help(and information)when i was building my engine and XJS, around 1994-1996.

we talked about heads,ports , valves,comp ratios, using chevy parts for internals,ETC.

his exact words for the flat chamber heads, was, it is a quiet chamber,so think about making it mix to a more homogenious fuel/air mixture.

he was the one(and tullius) to persuade jag to a custom port head,he said jags response was, we know all about head flow characteristics, dont need you!!
typical English thinking.

and the oversize valves in my engine were bought from Lanky from Grp44 racing overstock!
he helped with cam choice, and porting ideas.
YES he was one smart cookie! he will always be missed by any of the older guys from that racing era!

it seems that anything done today, on a hi-performance N/A Jag v12,has already been done, 30 yrs ago. i dont think anyone is gonna reinvent the wheel. more cubics will make more torque at low rpm and fall flat on the top end.

the only thing i have done to my engine more so than his engines 5.3s, coating pistontops,ports, valves etc, and extrude hone the plenums and runners.

and money is the limiting factor, i can easily see $20,000-$30,000. USD dollars for a serious Jag V12 engine, not counting any gearing or suspension mods, and manual trans will not count for much improvement in performance,(just a lot of fun shifting) we all know today automatics are faster than manuals.

 

20k!!?? Maybe all said and done. but just the motor sounds far feteched .1440 for liners crank regrind chevy rods and pistons titanium valves hypo valve springs and race cams i see about 5k

 

I am about 6 with all the lower end stuff, but I also went and bought much higher quality ross pistons than I needed

 

Rough Costs in the UK are as follows:-
Crank £4000
Block, steel caps line bore and big liner bore £2000 (BBC mains extra)(100mm Lip seal extra)
Liners (gasket)£1000 Liners (coopers ring) £2000 + rings £2000
Titanium rods £8000 steel rods £2000
Pistons £2000
California/TWR Heads £ unobtanium
Big cam carriers £ unobtanium
Big tappets / cap shims £500
Titanium Valves /retainers etc £6000
Schmitelhelm springs £1500 / unobtanium
Cams £1500 custom made at 0.6" or softer 0.54"
Oil pump internal £1000 external £3000
Baffels £1000 - £2500
Sundries about $2500
Labour time 100 hours.
With all the above you will of course need a better inlet better exhaust new ECU with sensors and dyno time to set the whole thing up. Of course thats not the end of the story either.
As always you get what you pay for, anything less than the above results in you ending up with less of course.
There is no cheap way to get real power out of these units. Even the XJR15 only had a std 6L engine, albeit with dry sump and decent exhaust. the rest was std XJRS. Maybe just get an XJRS 6L and get a custom exhaust made.

 

WOW! xjr5006, and at conversion to dollars, thats a lot of money!

course like you say,if your gonna do it right it costs plenty, or you can do it halfway, its cheaper, and you go half as fast!

i guess the engine you speak about could be called EPIC.

one of the problems with americans building hi-performance engines,they start with big V8s, and they mod out easily, respond to mods easily. so they think any engine responds easily to the same mods, nope aint so.

where as a jag V12 was designed as a luxury car engine, never any thought into more performance,like chambers,ports,valves, cams and associated components, etc. they respond reasonably well, to mods with expensive machining work, totally unlike USA V8s.

some quick calculations ,Jag V12, anything more than .450 thou. valve lift it needs a custom tappet carrier and cam followers(big money).

and we buy V8, over the counter steel main caps, so no problem, no such thing for Jag v12 , they would have to be custom made and align bored(big money). and if i were gonna do that mod i'd also add a steel girdle also.more money

just say we spent 5K on mods, i'm bettin you would be lucky to get 50-75hp more than stock, dont forget i been there and done that!

i have spent 5K on a BBC and got 300hp more.

and i'm stickin to my preference,a stock 6L with twin turbos, and custom tuning!
simple and effective!!!!