V12 95mm Liners
#62
Join Date: Jul 2010
Location: Austin tx and Daytona FL.
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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
#63
#64
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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
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
Last edited by ronbros; 01-22-2020 at 12:09 PM.
#65
#66
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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
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
#68
If you want the feeling of much better performance you’ll have to change 2 things. The rear end to a post body restyling rear end with the outboard brakes, Not for sake of the brakes, ( although they are much better and far easier to work on),but because instead of your 2.88-1 rear end ratio you will have a 3,54-1 which you need for the next change. Dump the automatic. Sorry, you need a clutch pedal because you’re going for the 5 or 6 speed gearbox.
Then pull your ECU out and send it to AJ6 engineering. Tell them you’re going manual.
The only other thing you can do inexpensively is get the car lighter. Stock it weighs nearly 2 & 1/2 tons! In stock configuration you could make another 100 horsepower and barely feel it!!!
Then pull your ECU out and send it to AJ6 engineering. Tell them you’re going manual.
The only other thing you can do inexpensively is get the car lighter. Stock it weighs nearly 2 & 1/2 tons! In stock configuration you could make another 100 horsepower and barely feel it!!!
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Mguar (04-04-2023)
#70
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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
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
#71
The HE is giving higher efficiency so I guess you get more power back for the amount of fuel.
more flow won't matter much if you don't get burned gasses out. If the air in the overlapping stages only pass directly between the valves some exhaust gasses are left effectively preventing the cylinder from filling with a mix that can be compared. If 5% of the combusted gasses are left 4% extra flow won't help. I guess knowing this for sure is trough simulation and everything else is just observations and experience with a bit of guesswork.
more flow won't matter much if you don't get burned gasses out. If the air in the overlapping stages only pass directly between the valves some exhaust gasses are left effectively preventing the cylinder from filling with a mix that can be compared. If 5% of the combusted gasses are left 4% extra flow won't help. I guess knowing this for sure is trough simulation and everything else is just observations and experience with a bit of guesswork.
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.
#72
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
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
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.
#75
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
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
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DaimlerMK2 (02-17-2020)
#77
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
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
Last edited by Mguar; 02-17-2020 at 09:30 PM.
#78
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Mguar (02-19-2020)
#79
s10n that is a good price , BUT they are not custom designed for a hi performance engine!
also they are cast pistons, not recommended for BOOST applications!
HE heads are known to lose flow rate as rpm goes up, but just maybe boost could help that design push more air into cylinder(that is what we are trying to do?)!
ron
also they are cast pistons, not recommended for BOOST applications!
HE heads are known to lose flow rate as rpm goes up, but just maybe boost could help that design push more air into cylinder(that is what we are trying to do?)!
ron
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.
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