building a 6.8 ltr v12
#81
#82
#83
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i agree warrjon; twin cam xj6 heads on a V12 would be a nightmare of machining ,welding, and engineering, just to get the engine to run and cam timing all things correctly!
then you gotta make inlet manifolds, exhaust manifolds, FI injector system!!
i seen one about 25yrs ago, and it never did run well, always something of a problem!
then you gotta make inlet manifolds, exhaust manifolds, FI injector system!!
i seen one about 25yrs ago, and it never did run well, always something of a problem!
#84
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#86
#87
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The problem is that unless you reverse one of the heads & change which end the cam sprocket is on, the intake ports of that head would be on the outside of the motor, where the exhaust ports should be, and the exhaust ports would be in the vee of the motor, where the intake ports should be.
#88
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88 that 4 cam jag engine should be cheap money, maybe get it done in an afternoon!!
No only kidding, on another post, i would use the Audi diesel V12 , comes from factory with twin turbos, quad cams, direct fuel injection and even a warrenty,.
and it would be way more dependable than a Jag V12 modified.
some times in these posts ,they forget that a highly modified engine could blowup, and you start all over again.
and if money is a factor , well, just may rethink things over!
No only kidding, on another post, i would use the Audi diesel V12 , comes from factory with twin turbos, quad cams, direct fuel injection and even a warrenty,.
and it would be way more dependable than a Jag V12 modified.
some times in these posts ,they forget that a highly modified engine could blowup, and you start all over again.
and if money is a factor , well, just may rethink things over!
#89
#91
#93
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I have seen these vids before. Every once in a while there's another fellow somewhere in the world who wants to do this, and one in maybe 10,000 of these guys actually acts upon his impulse.
I suppose it can be done. Clearly at a tremendous cost.
But to what end?
The flat head motor, when taken to its extreme (big valves, ports, more displacement) can generate so much HP that the twin cam four valve motor only begins to show to significant advantage well above 6-7000 RPM.
Who among us operates there? On the street?
It's great for racing boats, or track cars, I guess (although the TWR team, when given a four cam version of the V12 preferred the flat head because it weighed less and the CG was lower, and they could feel this in how the cars handled).
Otherwise, in a hot rod? It's a sure-fire crowd pleaser.
I think I'd rather conjure a set of cosmetic-only boxes that resembled the twin cam covers and fit those to a standard V12, if I wanted that kind of look.
my 2 cents.
I suppose it can be done. Clearly at a tremendous cost.
But to what end?
The flat head motor, when taken to its extreme (big valves, ports, more displacement) can generate so much HP that the twin cam four valve motor only begins to show to significant advantage well above 6-7000 RPM.
Who among us operates there? On the street?
It's great for racing boats, or track cars, I guess (although the TWR team, when given a four cam version of the V12 preferred the flat head because it weighed less and the CG was lower, and they could feel this in how the cars handled).
Otherwise, in a hot rod? It's a sure-fire crowd pleaser.
I think I'd rather conjure a set of cosmetic-only boxes that resembled the twin cam covers and fit those to a standard V12, if I wanted that kind of look.
my 2 cents.
#94
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mike90 I agree, some(most on this site) dont have a modified Jaguar V12 engine in a car. anybody got dyno sheets??
and i aint trying to pis% off the pope.
but clearly fantasy over rules logic,
(that 4 cam engine would cost,easily,$100,000. usd,or more), and i'm betting, when run hard on a dyno, would have serious problems.
its a show piece,for lookin at an dreaming of what could be.
and i aint trying to pis% off the pope.
but clearly fantasy over rules logic,
(that 4 cam engine would cost,easily,$100,000. usd,or more), and i'm betting, when run hard on a dyno, would have serious problems.
its a show piece,for lookin at an dreaming of what could be.
#98
#100
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the twin cam would have more low end torque (and possibly even vacum at an idle) so if it has low end torque thats purfect for what im looking for and possibly others look into that route. the heads are cheap so why not ?
heres the real question do they flow better? if they dont then there is no point i see in doing it
heres the real question do they flow better? if they dont then there is no point i see in doing it
Ultimate flow for HP is not necessarily the best for a street motor.
I was reading an article by the guy who built Formula Ford engines for Ayrton Senna and Johnny Herbert. His heads did not flow as much as others but his engines produced lower lap times due to more torque lower in the RPM band. In testing they found Senna was 1 gear higher in the chicane on the test track. And the rest is history......