I look at Jaguar XJS and appreciate the days when they were raced by Tom Walkinshaw . I recall the glorious sounds of the Group C Jags at Spa back in the 1980's.
I would like an occasional driver car with glorious V-12 sound. How is that done in a grassroots way for $5-10K?
Engine Swap something with a V-12?
Or purchase older BMW, Mercedes, or Jaguar and put headers on etc?
In reply to bruceman :
My bet would be megasquirt an old jag with straight pipes. Cheapish and simpleish.
At one point, I saw some BWM 850's for sale near challenge money. So between those and the Jag V12, that seems like the most reasonable prices.
For the later Jags and all the BMW V12s, converting to a more modern and reliable EFI is pretty easy- but unless the system is specifically designed for 12 cyl at 6500 rpm (which is a lot of computation), I'd lean toward running it like two I6's- which works since most V12's have separate intakes anyway.
In terms of the sound, I'd start with removing resonators and mufflers before spending money on headers. When I worked on a V12 program back in the day- removing one central resonator made the engine sound glorious.
So it's really down to the looks and ease of work more than anything else.
Weld two Duratec V6's together. 
Paging frenchyd....
I have nothing to add except it is amazing how exotic a 90's Jag V12 sounds with after taking a sawzall to the exhaust.
We are talking straight up Lambo levels of aural pleasure.
Of course 4 of the 4 mid 90's Jag V12 motors I have direct experience with all ran "ok-ish" but each had one or more broken pistons. Skirts and ring lands missing.
V12's are very expensive to build
I have to think that a V12 out of a rotted out Jag running on ITBs and minimal exhaust silencing would be quite the melodious cacophony.
This is not for a Jag, but shows the DIY initiative. Guessing bike carbs.
Not the cheapest or easiest way, but it does involve a Miata, and that's pretty GRM. Toyota 1GZ-FE with ITBs in an NB
The BMW v12s are not the best, the exhaust valve is so shrouded it doesn't make much power (for a v12) and I think it will impact how it sounds too.
Jag BMW Merc all offer some very cheap v12s out there. The cheap jags are coupes and the cheap Germans are large sedans.
Online vehicle inventory search at the local (MD) pick-n-pull turned up a BMW 750iL the other day...
S600 + long tube headers + exhaust = done.
How about a $245 (yes, no zeros missing) Ferrari 599? Cheap Ferrari . . . with a catch
Indy-Guy said:Paging frenchyd....
Eh... let's not lol
kazoospec said:How about a $245 (yes, no zeros missing) Ferrari 599? Cheap Ferrari . . . with a catch
Obviously the bid will go up, but after the fines, which don't count against budget as far as I can tell, this could be challenge legal.
Two VQ35s...double the fun or double the exhaust ear pain?
In reply to RevRico :
I think the biggest issue would be how many "officials" you'd have to bribe to get it to the dock. After that, I can't believe Ferrari couldn't help authenticate it.
Robbie said:The BMW v12s are not the best, the exhaust valve is so shrouded it doesn't make much power (for a v12) and I think it will impact how it sounds too.
Jag BMW Merc all offer some very cheap v12s out there. The cheap jags are coupes and the cheap Germans are large sedans.
Jaguar introduced their V12 before pollution limitations really put restrictions on V12’s in 1971. It was based on development during the 1960’s. It really is a version of the Hemi.
By 1981 in a frantic attempt to conform to upcoming California smog regulations. Jaguar used a version of Chevy’s fireball head of the 50’s & 60’s it shrouded the valves dramatically. BMW & Mercedes later followed with their own versions of that shrouding in order to comply with those same regulations. Effectively killing any real power production.
At the same time in order to improve fuel mileage they slowed the engine down with a 2:88 final drive ratio. And increased compression from 7.8-1 to 11.5-1 plus using the GM turbo 400 transmission.
In other words turned a performance car into a economy car ( that weighed 4200-4600 pounds) And while it is a great cruiser. Acceleration is adequate, not exciting.
yupididit said:Indy-Guy said:Paging frenchyd....
Eh... let's not lol
alfadriver said:At one point, I saw some BWM 850's for sale near challenge money. So between those and the Jag V12, that seems like the most reasonable prices.
For the later Jags and all the BMW V12s, converting to a more modern and reliable EFI is pretty easy- but unless the system is specifically designed for 12 cyl at 6500 rpm (which is a lot of computation), I'd lean toward running it like two I6's- which works since most V12's have separate intakes anyway.
In terms of the sound, I'd start with removing resonators and mufflers before spending money on headers. When I worked on a V12 program back in the day- removing one central resonator made the engine sound glorious.
So it's really down to the looks and ease of work more than anything else.
I can understand the mechanical aspects of switching from the Production EFI system to something like a megasquirt. But finding someone who has actually done it to a Jaguar seems pretty elusive. Then when I discuss using alternate fuels like E85 etc. suddenly no one is capable.
Maybe I’m wrong. Buying a megasquirt hasn’t helped, visiting the website hasn’t helped. I’ve talked to several people willing to learn at my cost but no one who has actually done it.
In reply to bruceman :
Simply hacksaw the Y pipe off and leaving 4 exhaust stubs run a straight set of pipes out the back. Headers won’t do anything for sound.
You cant run them to the side because you will only hear one side at a time, 6 cylinders.
The 1971-1980 V12 Jaguars will sound better than the later ones.
frenchyd said:alfadriver said:At one point, I saw some BWM 850's for sale near challenge money. So between those and the Jag V12, that seems like the most reasonable prices.
For the later Jags and all the BMW V12s, converting to a more modern and reliable EFI is pretty easy- but unless the system is specifically designed for 12 cyl at 6500 rpm (which is a lot of computation), I'd lean toward running it like two I6's- which works since most V12's have separate intakes anyway.
In terms of the sound, I'd start with removing resonators and mufflers before spending money on headers. When I worked on a V12 program back in the day- removing one central resonator made the engine sound glorious.
So it's really down to the looks and ease of work more than anything else.
I can understand the mechanical aspects of switching from the Production EFI system to something like a megasquirt. But finding someone who has actually done it to a Jaguar seems pretty elusive. Then when I discuss using alternate fuels like E85 etc. suddenly no one is capable.
Maybe I’m wrong. Buying a megasquirt hasn’t helped, visiting the website hasn’t helped. I’ve talked to several people willing to learn at my cost but no one who has actually done it.
It is easy. Doing a pair of MS on a V12 is no different than putting a pair of EECV's on a V12. BTDT. And E85 = just more fuel. This isn't rocket science. Look at a V12 as independent I6's.
Since nobody wants to help you, stick with carbs and a distributor.
In reply to alfadriver :
Thank you. That’s my fall back plan. I’ve got a 250 cu in roots type supercharger I can bolt a 1250 Holley on top all I need to do is weld a base for the supercharger up to the carb manifold. Put it on top of my 7.8-1 compression V12 but I suspect the FMV would put it over the $2019 challenge limit
Or just weld adaptors for four HD 8 SU ( 2”) carbs and skip using the supercharger. Use that on the 11.5-1 compression V12.
Regarding the megasquirt. Is a pair of them the secret? The first system used three 4 cylinder Bosch. Later ( about 1977-78 ) Lucas system used one ECM. I can use GM injectors, etc.
Is there a program or something already in the megasquirt to get it started and I adjust it from there?
Mind you the distributor works without any input from the computer. only the later 6.0 liter engines used a crank triggered ignition.
In reply to frenchyd :
I'll help you figure out the mega squirt! I've never done it either but you won't have to pay me to learn.
I'm in IT professionally so I'm confident I can do the computer side. You handle the mechanicals.
In reply to Robbie :
Thank you! That’s very kind.
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