Ron why would you change engines on a 4600+ pound car that is up to 45 years old?

If speed is your goal put that engine in a light small car.

I can see upgrading the engine for track work. Or as a tribute car etc.

 

!!

good point MG , maybe better to put a GM Ecotec into a Crosley HOT SHOT roadster, they weigh around 1800 lbs factory stock!
had one around 1952/53, cute but gutless 1500CC. swapped it for a Triumph 650 T bird motorcycle, NICE!
ron

 

That engine is in a MGB that runs Autocross. He started out with a Jaguar V12, well go over to GRM ( Grass RootsMotorsports ) and follow the story. I wish I could figure how to put a link here.

 

you mention Grass roots motorsprts,, the Owners of that magazine and company , are personal friends of mine, known them for over 25yrs! Daytona/holly hill FL.
fact is when i had my engine business in Holly hill, around 2003, they came by shop and were on a vehicle review test, some GM SUV thing, showed the small engine!
i said that engine is gonna be one of these best hi performance engines yet! ECOTEC!
ron

 

I hope you get a chance to read the story. Excellent read. It’s a MGB GT with a Jaguar V12

 

i'll bet an MGB with a GM ECOTEC , would blow it away!
fact is GM has a book with all the details on how to make 750hp from one of that engine!
and it could be done with an automatic trans, with 4 speeds , they did have a car built that way, but a lot of guys were screaming "unfair advantage)!
ron

 

"and the BEAT goes on"

 

I not interested in much better performance at this time. I'm interested in getting the car back on the road, at minimal cost, given the availability of pistons/liners (fading fast here in the USA) for the busted HE V12 under the hood. Yes, I know it's probably scrap time, or LS1 time, but in the best of all possible worlds the V12 can be refurbished without spending more on parts and machining than the car is worth. If I wanted a Chevy V8, I would've, and could've, bought a Camaro.

 

Pawn , its just the reality of life!!
live life untill you die!

 

HEY MG ,youtube, SHELBY GT 500,5.8L ,CNC head porting!
it will show how far behind we are,as most on this site(not to be silly).
i'm in process of really taking an expanded view of the lovely Jag V12 , mine included!
way back after doing many performance mods , i was not impressed with performance!
my yardstick was my 1992 Camaro ,with 467" BBC engine, the same mods done to the Jag did not make much final power!
i was dissapointed , an EXOTIC all aluminum block & heads ,V12 , left me cold!
ron

 

HE does not stand for High Efficiency. It means Help Emissions.

California was about to come out with a tough new law to deal with the Heavy smog they had. Since California accounts for over 50% of Jaguars production and Sir Lyons had spent massively to get the tooling required to build its new V12, plus introduce its new models. Jaguar simply had to clean up the engine.
By patterning Jaguars combustion chamber after the Chevy Fireball head emissions were reduced enough and as a side benefit part throttle fuel economy was improved.
The trade off worked. Added with other changes, driven gently a V12 powered car went from approximately 10 mpg to 17-18 mpg
The real cost was in power potential. It was pretty straight forward on the earlier head to make a lot of power. Not at all on the HE head.

 

The Camaro was a lot lighter than a Jag and not
Burdened with such a tall final drive. Beside Sir Lyons never wanted a drag racer. His goal always was a smooth torquey luxury cruiser. A Bentley type car.
Look at the lift and duration specs on a Chevy compared to a Jag. I’m not saying new designs aren’t an improvement but don’t forget that V12 was first designed back in 1954 and then modified just before production in the late 60’s to go out to 500 cu in. While still using some of the machinery he bought in the WW2 period.

 

Hi All
would quad cam heads be a better bet for the v12?

 

maybe , the cost would make things not worth the expense,, fact there is a post on Jag-lovers ,, quad cam V12

 

You can put in an order: https://www.facebook.com/BuildingTheLegend/

It's not a 4V head, but a brilliant re-imagining of what Jaguar would have/could have done had they put the XK tech into the V12.

For us regular V12 owners I've speculated with Neville that his custom uprated oil driven chain tensioner might be useful for us mere mortal V12 owners.

~Paul K

 

drawing from Jaguar , on the proposed 4 cam V12, they did build and tested ,made 502HP at 8000revs!

 

ThT was what the XJ13 made with 5 liters. Design to run at LeMans. The SOHC cam XJ engine ( used in the XJS ) made much more than that when spec’ed out for LeMans.

Group 44 started out at 525hp and finished at 630 hp
TWR was at more but I can’t find my numbers right now but it was reduced by the fuel mileage requirement.
Lister was at 804

 

me being in Daytona for 30yrs , seen in person one of the Lister Storm cars, it was somewhat fast but debris caught it out and they were out of race!
engine couldnt see because it had the biggest air plenum i have ever seen, almost as big as the V12 it self!

 

I have seen regular production cast pistons survive 30 psi of boost!! There are two ways to do that. First you can disassemble the pistons and open up the ring to .030 end gap. Or you can buy an engine with over 100,000 miles on it and the ring wear will typically be high enough that if you use E85 you won’t need to take it apart.
The advantage of a high mileage engine is that the wear allows greater oil flow required in racing applications.
The down side is a visible display of oil smoke on deceleration ( blue smoke). Plus higher oil consumption.

If you keep boost down to 6 psi. No real changes need be made assuming you keep mixtures around 12.7-1
You can’t really do that using stock Jaguar ECU’s. Aftermarket ECU’s can be used some like Megasquirt are self learning. Hook the wires up correctly and it will start and run and over time self adjust.
If you have a lap top and know how to tune. You can do it. To do so safely use a chassis Dyno. If you aren’t familiar use the tuner at the chassis Dyno although some of them really don’t how to tune. Ask questions first.