My guess is a spacer under the cam carrier. Maybe even longer valves and springs, I would have thought you would have spring bind above 0.450

 

warron some one says that you need custom tappet block ,for larger diameter tappets(cam followers),! also taller!

and looking closely you may even need custom large cam covers,so cams dont hit the sides and top.

just guessing a lot of money, and then there is the valves and spring arraingment.

then you got the pistons to deal with(valves hitting pis. tops).

can we say, many thousands of bucks!

in this day and age, as 5006 says,hehe, a full wack, 7.5L jag v12 , could cost 30,000-50,000. us dollars.

YUP, i'm out on that one,,
( i just might get an AUDI V12 TDI, and see what a nice smooth and RELIABLE engine, with only 850 lb.ft torque.,)very light weight i may add, even comes with twin turbos,).

course maybe audi dont know much about turbocharging, OH yeah!

 

Ron, I think you'd need a taller tappet block or springs that allow more lift before they bind

 

So since we are on this topic, I will ask a question I've asked before in the X305 (V12) area: has anyone tried the 'full house' of AJ6 Engineering mods for the 6 litre? ie: ECU, throttles, intake plenums, exhaust, etc?
If so, how much better?
cheers,

 

I looked at the AJ6 gear but it's really expensive over 3000GBP plus shipping and everything but the exhaust is on an exchange basis so need to ship ECU manifolds and throttles to the UK.

I think all of this can be done locally for far less cost.

Manifolds - cut the plenum off leaving a flange around the runners have a new larger plenum fabricated with the TB located at a slightly larger angle to the top of the plenum, while its open add trumpets. Have a look at the BMW 335 manifold TB is between 3 and 4 but on a much greater angle than the V12 and the plenum is also much larger.

TB - I think these are large enough they just need to profiled on the inlet, ie radius the intake side.

ECU - MegaSquirt, can be done for $1500AUD even cheaper if you use the dissy. Or you could go Delco 808 if using single or dual (Marelli) coils this could be done for under $800AUD.

My full mandrel bent 2.5" SS was $2000 from the headers even less if in mild steel.

 

guys lets not forget the chains,, something has to drive the cams when they are raised higher up!

that goes for the head spacer plate thing also!

before all is said and done,, lots and lotsa MMMOOOONNNEYY.

then it blows up,( NAH, we wont go to that subject).

 

Yep big cam carriers require a chain with and extra 1/2 link,

 

Hi is this with 6.0L HE or pre HE heads?

I have a 1994 6.0L with forged crank and will be building it next year. I am gathering info ATM so I build this as a good street engine. I don't want 700hp @ 8000rpm I will be keeping the stock 6000rpm limit, I want a good flat mountain of torque.

 

The 450 is stock XJRS / XJR15 engine, the .415 cam is the XJR15 cam and the injection was the zytec system, Pistons were cosworth and just about everything was stock.
The 601 and 635 are fully modded / CA / TWR headed full race flat head engines.
the 7.3 is 84 x 96
the 7.4 is 88 x 94

The deep sumps can get smacked in road use and can nearly close the pick up be careful, but why use such a sump in the road anyhow?
Oiling system, I'll leave it to individuals to sit down and compare the components of the bypass and full flow system and work out the hows and whys. To sit down and work out the flow in a standard crank and cross drilled crank and where and if the bearings should be plain or grooved to suit the oil flow from the block to the BE bearings.
There are wider pumps for those requiring better flow. I have however never seen one used with a system that will utilize it, more often when you think about it the extra oil pumped will straight away open the bypass an be dumped right back into the sump pan.

Other issues are people rebuilding engines or upping the power of engines both of which will produce more heat and them expecting a 20 year old partially blocked / marginal rad to cope. The V12 does not have overheating problems, its the lack of thought of the owners / preparers that is the problem.

The road engine and its normal rev range works well for the std water pump, up the revs and you will need to lower the rotation of the pump in relation to the engines revs, forget this and you over flow the engine and heads it wastes power and risks cavitation.

 

Thanks for the info

My car is a Marelli 5.3L. Front and rear suspension and cooling systems have all been fully rebuilt ready for the 6.0L I have sitting in the shed.

I heard from a guy here in Australia that the HE combustion chambers can be re-profiled to improve both combustion and flow, have you any experience with this or is it just hearsay?

 

so you're telling me that the xjr15 used he heads?

 

Yes, standard HE heads, even got a pair that TWR have marked up for cc ing to get a smoother engine, all part of their 'blueprinting of the standard XJR-S engine.

 

xjr5006 where do you get all this stuff

 

Been racing V12's since the 80's and buying up TWR from the receivers helps. Built a few Lister 7L engines, some with that horrible twin supercharger set up.
Build a couple of XJR15s and been racing XJR5 for a decade. So guess I have come across most things V12 by now.
What I have appreciated long ago is that to up the power of a V12 you need 'a package' by this I mean you need to realise the pitfalls of the v12 and make a series of changes that complement each other. The race stuff forget; you are unlikely to source the correct 'package' to utilise the components properly, if you do find some race stuff sell it to me.
The V12's main problem is restricted inlet and restricted exhaust; decent headers solves the latter and the inlets are a bit tougher to sort. The heads need the inlet ports opening out to the gasket, you can do this yourself with die grinders and flap wheels, a simple blending job doesnt even need the heads coming off! The inlet manifold is the main problem, the AJ6 system doesnt give much for the money and doesnt solve the too narrow inlet to the head problem. Thats why TWR cheated with the big inlet manifolds they had cast up (v12 engineering ) You can do a very good job yourselves but it takes time, load and loads of time. If paying someone to do it then the V12 eng. stuff from Bob Tilley may become attractive. Remember the bigger the engine the worse the problem in this area. The ag here may well make throttle bodies quite attractive, all depends upon what you really want and expect to end up with. You can end up with thousands of your hard earned racking up very quickly so be careful.
So yes you can get as much as most will ever want from a 5.3 / 6.0L without too much being done really but getting much more than 500 horses becomes very expensive very quickly. Remember this engine is over 40 years old now so comparing it to modern crate engines is silly, bit like comparing a V12 to an engine from the 30's.
At the risk of a bit of plagiarism; if you have one of these engines appreciate it, enjoy it and look after it, the likes of it you will never see again. (this was originally said about the 427 and in particular the SOHC ) So lets get real, there were at least 3 times the number of 427 SOHC engines built as there were of Jag racing engines, and the jag has 1/2 as many components again being a v12, look at the prices of these babies now. The Jaguar V12 is silly cheap for what it is.

 

yes you have a point.

my car is a street car, and when I set about building it I wanted to build a motor to show everyone else it could be done and how to do it.

I plan on getting headers eventually, and I plan on seriously upgrading the intake, im slightly worried if I go with the group A Intake from bob tilly that I'll lose mid range torque, what's your take on this? remebering that I have a 400cubic inch engine

 

5006, what 427 SOHC are you talking about, Ford or ??

 

that would be the ford, I know of a.guy who has a 427 sohc in a falcon or galaxy, either way it's a ridiculously rate car and he wasn't even aware of what he had when he brought it into my shop

 

my shop as in the shop I work at

 

I have to agree with the intake manifolds. Cal have a look at the manifolds on the BMW and Merc V12. This would be a good place to start in modifying the Jag manifolds.

I have been thinking about this for a while and I think there are 2 ways to go, depending on how much work you are prepared to undertake.

If you cut the runners off the plenum and fabricated a new plenum. This could be done with fiberglass then bolted back to the runners. the runners could be flowed and modified while access was good. To mold the plenum, use body filler on the stock plenum to shape it (this will be the inside of the new one) Fiberglass over it and add a flange after.

New equal length alloy runners and flanges then make the plenum in fiberglass.

I have a spare set of intake manifolds on my 6.0L and I think I will do this next year. Once I have the rest of the car back together.

 

WARNING:
Not for the purists::icon_eati ng:

696 HP 'Draguar' is No Ordinary Jaguar