70mm stroke 95mm bore = 6.0L and I know for a fact you can get 600hp @ 7500rpm from this combination with flat heads, the right intake, exhaust and cams.

Talk to Norman Lutz he has built many 6.0L race engines using this combo, in fact he is doing my 6.7L 78.5mm stroke 95mm bore. Stock valve springs are good for 7500rpm although Norm can advise you.

As for ignition I would stick with coil packs rather than coil on plug which can be problematic and require the addition of a cam sensor for sequential. Even the MS2 will run a V12 wasted spark so no need for EDIS run the Ford coils directly from the MS, or add an external box with the ignition drivers, so the MS ignition output is logic level.

I have GM V6 coil packs that Ive removed the electronics from and installed BIP373's to drive the coils directly from the MS2.

Thanks for the input Ron. This will be a multiple year build, 2018 will be to get the ms working and along with EDIS or coil on plug if possible? Depending on cash flow I'd like the ITB's as well. Manual transmission will be 2019.

a little thought about hi-rpm engines.

1st automatic trans .like the GM 400 dont really like 7500+ rpm.

also same of the 700R4 most shift up below that rpm anyway!

and usually automatic trans , need some mods to be made to work at 7500.

that why i say a manual trans.

now lets be a little realistic (who drives around at 7500 rpm??).

of little interest is my V12 has the old distributor using a simple Crane XR700 box, and a generic chevy advance curve, single coil, it revs to 6500 pullin good, and will go 7000 .

if i have not got the race won by then using torque ,to just get ahead of opponent , but in real time now he has to get past me before we run out of road or comin into a corner!

ITB's can be tough to drive slowly, they often act like full on or nothing and stall going slow.
stop and think about it a regular large single T plate can be modulated smoothly, but just imagine 12 Tplates opening slowly is harsh and jerky!

that why you hear some multiple ITB quick revin moving around the paddocks.

just some things for thought!

ron

This will be a weekend warrior car. Lots of lapping days, and summer driving. Couple buddies have civics but I'd like to show them how a 4000 pound tank will fly around a track.

I'll be going with a new manual transmission. I was thinking a t5 from a mustang but they are rated for 300hp. If I hit a lapping day it may not last long

things are changing faster than i can keep up.

NAIMO Composites.com

carbon fiber connecting rods,???????

I’ve read this thread from to top to bottom and there is loads of great info.

It appears no one has made a naturally aspirated 500hp from HE heads but jaguar got close at 450hp with their XJR15. Many have made 500hp using flat heads. Whatever you do a package is needed, engine management, heads, cam, exhaust and increased capacity.

If I’m reading this right the XJR15 made 450hp with stock HE heads. Is that correct? Notably the XJR15 had extractors which some people think aren’t required on a V12.

For the 500hp, flat heads must be used, the heads must flow 200cfm?, the choke point needs attention and intake manifold need to be fabricated. So who offers a package or a detailed recipe for success?

Regarding the intake manifold I was reading last night about intake manifolds and people adapting an Aston Martin intake to a Porsche 928 and a Porsche Cayenne intake to something else. It got me thinking can on of these new fangled intakes be adapted to the V12. I realize you would need find one that lines up reasonably well, two sawn and joined together to make 12 cylinders and some sort of adaptor plates. Reaching the spark plugs needs attention, Aircond compressor moved, the dizzy needs to be removed, etc.

Hopefully the width on the intake manifold designed for a 90 degree V8 with 4v heads may be similar to what is needed for a 60 degree V12 with 2v heads.


https://cimg3.ibsrv.net/gimg/www.jag...6274538f6b.png

You don't need to go the those lengths, a simple way is to use the OEM manifolds, cut the plenums off and weld 100x100mm box section. Or for an all out system new aluminium runners and 100x200mm with TB's on the front, I saw a set Norm made that were on a 500hp XJS taga car. You could even make them out of fiberglass instead of aluminium.

Maybe but using the original runners still leaves with runners of unequal length, possibly less than opitimal overall length and internal diameter, no taper and a material that conducts heat. A total custom metal manifold would be better but not easy. Using a modern plastic intake manifold and a say a 1” ally adaptor plate maybe easier and give better results. It would definitely free up a lot of space under the bonnet.

.

John ;your question,,who makes a package for 500HP from a Jaguar HE engine , answer at this time NOBODY.

OK, TWR finally got 500hp at close to 8000 rpm, but it cost the factory close to 1 one million and 3 yrs screwin around with all types of mods.

dyno charts showed that engine did not make USEFULL power untill 5000 RPM, and yes it used pre HE heads modded in many different ways , most of the info is still secret, along with cam and valve train mods.

just force feed the SOB and be done with all the expensive mods!

Not if you add bellmouth trumpets to make them all the same length, but 500hp would need larger diameter runners, easily fabricated. By the time you start cutting and shuting manifolds I think making a new of custom ones would be less work.

Why re-invent the wheel, go with what is tried and tested

Flat heads
large valves - biggest you can get in the bore, 95mm bore allows larger valves.
0.415 cam
Larger manifolds especially the plenum.
free flow exhaust

or turbo charge stock 5.3L flat head.

The XJR15 made 450 from stock heads with the race style headers. You won't be able to fit these headers or even get a set. Cams were .415" .
Up the capacity and you up the torque but kill the top end with the standard inlets designed for road 5.3. (even if fitted to the 6.0.)
Just dynod an engine I have built and it gives 555Ib/Ft but the top end power is disappointing from my point of view. Inlet port is 38mm so I am looking to up this to the 40/42 mark. It all depends on how much meat is there on the inlets. These inlets are from 36mm opening to 46 at the plenum as standard.
Yes the inlets are available just check out my pics. Want to do it yourself then I have castings getting ready for a UK February show so time enough to replace them and get new machined up.

Warren aren’t those specs close to Ronbros’s except for the plenum and I think he said he was getting about 340hp?

xjr5006 it really suorises me that stock HE heads can make so much horse power. Are the headers a big factors because I’ve read on here many times that header aren’t a big factor on a V12? Do you know what intake manifolds were used?

Regarding the 555lbfts engine you are building... can we please have some more info. Bore, stroke, 555ftlbs @ ?rpm, hp @ what rpm, cams, type of heads, intake manifolds, etc.

.

john my best of 355hp was at the wheels , rough guess maybe 390hp at the flywheel, (i hope).

john quick thought,, you figure 200CFM NA will make close to 500HP,!

now with a proper set of turbo's and just 15 psi measured at the inlet manifold , CFM
would go to 400CFM.

should make well over 500HP, what say?

I think a stock 100,000 mile 5.3 with 15lbs boost would make about 500hp and not be very reliable. To be reliable it would need a full rebuild, suitable pistons and an aftermarket ECU and ignition system on top of turbos, exhaust manifolds, big exhaust, intercooler and plumbing. The engine bay would be crowded and you would probably get 550hp+. A decent 500hp big displacement engine would be less complex and maybe cheaper.

When Bruce's 6.7L twin turbo race car spun a bearing he ripped it out and installed an old stock 5.3L he had lying around running 15psi around 600HP and it lived a few race meetings before being pulled and rebuilt.

The turbos fit easily where the air cleaners are, and you can run stick manifolds upside down

[SOLD - JAGUAR 1977 XJS V12 TWIN TURBO Race car - CAMS LOG BOOK - JAGworks



Hi Warren if I’m reading this right the stock 5.3 lasted a day on the race track and was replaced with a AUD35,000 dollar 5.3 which made 550lbs per the advert and 543Lbs and 467hp at the rear wheels per the dyno chart. The 6.7 was making 610hp before it spun a bearing.

Turbos are certainly interesting and legal in oz on a 5.3 but I’m not sure they offer the best bang for $ and wouldn’t cause hear issues.


QUOTE=warrjon;1798193]When Bruce's 6.7L twin turbo race car spun a bearing he ripped it out and installed an old stock 5.3L he had lying around running 15psi around 600HP and it lived a few race meetings before being pulled and rebuilt.

The turbos fit easily where the air cleaners are, and you can run stick manifolds upside down[/QUOTE]

The engine was still running after the weekend the think rings seized, as the engine had been sat for a long time. I think if he'd pulled the engine and replaced the rings it would have lasted longer. I meant to say a few races not meetings. Have you seen Bruce drive, he is pretty hard on the car, he broke a Jerico dog box with the 6.7L, actually blew a hole in the side of the case.

I was going buy his long stoke crank but the engine was a rope seal and mine is a 1 piece lip seal.

467 rwhp is about 560 at the flywheel, Norm has got 610hp from a 6.0L NA, although I do know that the torque the turbo engine made was phenomenal. I saw him come out of pit lane at Eastern Creek and light up a set of warm 300mm slicks like a V8 Supercar.

If you do this type of HP/Tq and traction you will need to strengthen the rear end. The TT XJS race car had the rear cage braced to the boot floor and the boot floor was warped from the twisting of the rear end. You would need to brace forward to the chassis rails.