great info; but i think money wise, this stuff is way over my head!

i dont think there are many guys here that will buy into those components.

some of them here are concerned over a replacment for the cigar lighter! DUHH.

but that should not preclude you from moving ahead, HEY i love this stuff.

 

Cam bucket group44 heads





Valve seat empty





Valve seat inlet empty

I got my new verniers today from ebay with a broken display fortunately they still work. So i took some measurements in inches...

 

Hi everyone. I got the results today for the flow testing. Out of the box they flowed 643hp at 550 thou lift using 1.8 inlet and 1.5 exhaust valves. That's with a 3 angle valve job. Apparently there's more in them with a minor port and polish, but I didn't want them to touch the ports. The valves are apparently the best size for this head. So I'm pretty happy with that. That's theoretical hp with everything at optimum. Now I guess I have to find the right camshaft. I want to build a 7.5l torque monster. I don't think 600hp and 550-600lbft is too much to ask for?

 

Daddycool454 and XJR5006 I assume you're aware of the Tullis leftover 8.5L engine bits that showed up on Jag-Lovers via Peter Crespin?

JagFORUM Logon

New 95.75 mm bore Heron race type pistons
New billet fully-counterweighted 75 mm crank
Flat heads ported with inlets 1.771''
Exhausts 1.420''
Crane built-up cams with 0.460/470'' lift and long
duration. Tappet guide blocks with oversize tappets to be
fitted after boring.

Paul Kobres
85' XJS V12
96' X300 VDP

 

Peter corrected that post to say he meant 6.5 liter, not 8.5 liter

 

Hi Daddycool454, while browsing the forum I came across this thread regarding the heads, just wanted to ask what your plans are regarding valve springs for these heads????.

Regards, Allen (SpringMan)

 

Springs are and have been NLA for many years, working on this right now and have got it down to valve tip length / top hat shim availability and collets (locks) So yes sorted but there are a number of options here.

 

Hi, Well when your ready bounce the specs your looking for off me and I'll check our listings for a match up and if nothing we have in stock matches we'll do up a design and quote you prices based on the quantities you may need.
Regards, Allen

 

Do you have the actual airflow data in cfm or other units ?

 

Thank you for this lead,
Found pursued purchased and now put away in my warehouse; Heads are special casting but not CA but SP5; These heads are actually in one of the engine log books I have from Gp44 engine # 014 or 015 from memory.
Came with high spec ali crank bearings for BBC with block reducers. Saw loads of these caps at 44 many years ago but this is the 1st time I have come across them in an engine.
Thats 6 Gp 44 engines making a pair and a spare for both my cars.

 

.

xjr5006,, you are just having all the fun!!!!LOL

seems as tho Grp 44 did a lot of good for Jag V12 engines, especially when Coventry was spending the money!

his remarks were not very nice when they stopped the money!

today he happy that he made many performance changes to the engines and cars, we may not have what is available after all!

in the paddock at Daytona back few years !

 

This is really interesting. I personally would be interested if the the price was similar to that of an LS3 swap which I doubt. I know there is huge value in keeping the engine a Jaguar V12 but with engines like an LS3 swap available ignoring the "Keeping it original" theme is it anywhere near as cost effective?

 

if you have to ask what it costs ,you cant afford it!

nothing gets attention more than saying its a V12 cylinder engine.

and i have a Buick Grand national with an LS3 in it!

 

Group 44 built just 18 Jaguar V12 engines. The last one never went in a car and was 1 of a pair that went to the UK for F1 Power boating. I have the log book (and the engines) and its all in there. That's not to say that the engines weren't rebuilt a number of times, they clearly were.
I am now working with experts to see just how aggressive a cam we can run viz how fast we can open the valves and keep them open but to the same cam timing as both Group 44 and TWR spent a fortune testing to sort out. With this will come recommendations as to what springs and diameter buckets need to be used to achieve that fast valve opening.

Could be a couple of months until we know what if any gains we can get in this area. Time have moved on, lets see if the computers can max things and give us something here. I'll let you know.

 

Hey XJR5006, I'm glad they went to a good home. I wish Lanky was still around to answer questions. He was a wealth of historical knowledge.

It'll be interesting how well the old heads blend with the new modern materials and how much more can be pumped out of them. Any plans to wet-flow test them or do any Computational Fluid Dynamics (CFD) analysis?

Paul Kobres
85' XJS V12
96' X300 VDP

 

for interests, i bought a set of new 3MM oversize valves for my engine , bought from Lanky in 1994, they were well shaped under the head, and slightly under cut at stem!

single piece forged Stainless steel, probably the best available in 1986/87.

as i remember i had to cut the exhaust smaller about .040 thou. because the inlet and exhaust were close to each other, and stock exhast seat was to small diameter,my seat is at the outer edge of the seat insert, (my heads were 1978 factory, but i can only say i ported and smoothed in areas that seemed proper, and blended the seats and bowls to a smooth flow visual).

cams are Crane regrinds Nitrided, i had them profiled and closest comparision was Porsche 1974 N/A race profile,(ancient tech by todays standards), they run fine 21yrs later , and i used some springs that Lanky sent, shimmed .060.,said be fine for street use!

i removed the cam covers last year,(oil leaks), and cam lobes look like new, along with buckets!

 

Hi Boys & Girls,
its been a while and some awesome posts.
After reading all this I am getting excited again, but the budget isnt here this year for this. I got a quote from the heads guy today at around $6kAud to supply and fit valves, seats, shims, guides and minor porting and blending. So that is definately towards the end of next year. Im also waiting for the quote for a 6L bottom end specced to 7.5L. At the moment Im trying to get all the work done thats infront of me, reminds me of supercharged TR6 when i was paying the heads off, business gets a little quiet then spazzes out and cant keep up... In response to an earlier question, I dont have any further flow data, but will attempt to get it. By the way congrats Xjr on expanding your collection Ron your alloy & steel look are getting me excited. Just to ad further distraction I bought an xjrv8 recently and another for parts... somehow I think the 7.5L 12 will be M U C H more rewarding

 

I'm still watching! I probably should take/post pics of my project. It still seems so outlandish, that I'm wanting to see it work before I go talking too much about it.

 

Who's going to do this work?

I've had a price on a big bore kit for my 6.0L (making 6.7L) including rebuild at 7k

 

must be me , $7K sounds high for only 42 cubic inches increase of displacement,along with a rebuild. not counting all the other performance components needed.

most of this stuff(at least for me), is all about the bragging rights when talking the talk, few here could actually/rarely use the complete HP that can be made!

so i'd like to say ,YEAH, 427+ cubic inches , like old times ,it just sounds Kool.

plus i have always liked a stroker engine.

but if thats what you want ,go for it!