I found an 89 jag with the v12 in it, I am wondering if anyone has switched this engine over to a carburated set-up, and what was used for a distributor. Any help and pictures is appreciated. Thanks Rick
Go to you tube and search "Steves mighty V12 Jaguar" and you can see one with carbs and hear it run. (It sounds great!)
500 bucks a piece for carbs is not much of an option to me, I was hoping to see someone that used some old 2 barrels or a single or dual 4 barrel. It wouldn't be hard to build an intake, but I would like to see some options. Thanks again, I like the pics I have seen so far.
If you carb the thing for 600 to 650 cfm and use the dizzy from an earlier XJ you should be able to run it ok. But I got to say these engines were far better on the injection than on carbs, Why do you want to change it ? Just modify the stock injection so the intakes come up into a plate which takes a scoop, and stick with the injection. At best on carbs it will only ever run just about as good as injection, and that could take a whole pile of jets and air correcttors to get it that good.
Brilliant engine, but beware, they have about twice as many moving parts as any other production engine ever built, so be prepared to do a lot of fiddling to get it running reliably. Cheers, Glen.
If you want to go back to carbs then the easiest and cheapest option is to use the original SU setup for this engine. Carbs are easy to rebuild and they are often swapped out when the engine is upgraded to Webers. I think SU's with polished dashpots is a better looking set up and the engine (well, almost any engine) runs sweeter on SU's. Economy is usually better too.
Early versions of the motor were carbed and I believe had a more conventional dizzy. If you feel you must switch, you can probably switch. I thought these motors bolted to a GM auto, a TH400? That would be nice. I'm with Thunderace about the plate and scoop though. Making an intake is one thing, making a performance intake is something else all together...
I just spent a very enjoyable fifteen minutes on that article about the V12 Corvair (aka Jaguair). The guy was an engineer extraordinaire. Few carbuilders would have taken the steps to produce such a well-sorted-out car. It is truly a hot rod in every sense of the word. If you're intrigued by innovative thought and engineering genius, spend those few minutes perusing this article. It's an eye-opener. dj
Yeah, that is one of the most well thought out engine swaps I've ever seen. I take the time to look through it at least every 6 months or so. It still amazes me.... I remember the ones I worked on in the 80's having GM transmissions in them. Can't remember if it was a 350 or 400 though.
GM TH400 77 to 93 before that V12's got a Borg Warner 12, Crane Cams do a couple of ignition kits, XR700 or XR3000 which would get round the problem of sparks. Still don't yet get the why bit, normally I would be trying to figure away of fitting injection, not how to go backwards. Injection is going to give more power per gallon, which these days equals bucks good enough, so you are getting more horses for your money, hence why would you want to get less power per buck and give yourself a whole mess of work trying to feed the big cat on a badly organised leak ( carb ) ? I would have to check for NA but certainly here in the UK the V12 did not have SU's, early ones had ether downdraft Webers or more commanly Sidedraft Strombergs, four of them which in the case of the side drafts would not fit in the V so were hung out over the cam covers on horrible long manifolds so throttle responce was not as good as it could have been. It's minus three out, car out on the drive for days not started, I turn the key and the starter barely turns the motor, but coz it's injected it lights straight up no problem, you can't beat this squirting fuel under pressure game.
This Rod was just on Ebay. looks like he used 2 Holleys, he claimed it runs, maybe you could ask him details http://tinyurl.com/79pcya Mark
I got to see this thing when he drove it to the machine shop one day. Unreal! Workmanship is first class as is enginering. I believe he said he was a retired enginer from GM
there is a dual 4bbl setup for marine application comprised of two separate manifolds. not sure who makes it, but i saw them on the local craigslist a couple of times.
The reason for going to carburation is because it is simple, and I understand carburators and making them work properly better than I do fuel injection. I will research it more, I do like the idea of using FI, but I do not want the wiring to be so complex that I can't make it work. Also, the car is non-running right at the moment, I suspect it has something to do with the ecu, and I do not want to spend tons of money getting the car to run if it is in the ecu. Thanks for the replies, if there are any more please post them.
Fairly easy to fault find, a pressure guage to check fuel rail pressure, and a small 12v blub to check if the injectors are being pulsed, it's a very simple system, High pressure pump charges the fuel rail via an in regulator valve and then on the other end of the rail is pressure regulator which allows excess fuel back to tank. The ECU is little more than a clever amplifier that takes pulses from a crank sensor, amplifies those pulses and sends the pulses to four groups of three injectors, The throttle pot tells it 'how long' to squirt, and the other inputs are minor corrections (5%) and cold start and warm up idle related. Ok it involves some wires, but in truth compaired to many carbs it's actually far less envolved. I did a quick search and even found a company who sell downloadable instructions to enable the EFI system to be retro-fitted to E type V12's so there should be no problem finding information on the injection system.
You can go to carburetion, give the car a 300lb diet, and pick up a bunch of power by swapping in nearly any 350 Chevy with a performance cam. For all the complication, weight, and technology involved, Jag V12's don't put out all that much power.
A small block Chevy is 575 lbs., Jag v12 is 680. I was wondering where you got the other 200 lbs from.... just curious.
FWIW, my 82 XJS has a 454/700R4 in it. I had to take 2 shims out from under each front spring to bring the front end down to stock height. Apparently the V-12 weighed more than the 454.
Unfortunately NA got a de-tuned V12 only making a mear 265bhp, So yeah a 350 with a cam could definately make more power, Even wound out to the limit, stroked, bored, camed the Jag is only ever going to give five hundred geegees, where sure we could take the 350 out to give far more power. But where the V12 scores is the same place the V8 did over a four, more cylinders equals far more than just brute power. The V12 is not light, I have long suspectted the 680lbs figure is 'with everything' because when we have had the engines out on the floor it's perfectly possible to move them, while other things I have sworn were bolted to the floor . It's a great old lump, and will look fantastic with six chrome pipes on each side, did you ever see that 34 Coupe that Martina Hansson built ?
Nobody puts a in V12 Jag engine in for power, it's all for the coolness factor. It's like running a hemi, a small block chevy is lighter and can make more power with a lot less money. A lot of guys like those boat anchor hemi's. My $.02
From one I did a few years ago. I was told by the people at John's Cars that it would be a serious diet, and having a set of race car scales handy, I did a "before and after" weight. The difference, IIRC, was about 300 pounds. I never got into weighing individual components. I did have to get different front springs, otherwise the car would have been great for spotting raccoons in trees. Considering building another one for a daily driver; they're getting so cheap it's silly. Buy one for 2500, drive it for awhile to figure out everything that's wrong with it, then swap in a LT-1/700R4 combo.
For some reason I'm really disliking the apparently now standard reply to motor posts of "run a Chevy 350." He wants to run the Jag motor. He asked about info on running the Jag motor, not a Chevy. If he wanted to run a Chevy, I imagine he would. Now do you actually something useful to add to this post about running the Jag? Any good info to pass along, or part numbers to try? No? [size=+3]THEN SHUT THE FUCK UP![/size]
If you don't want to run the stock FI, you can look at a MegaSquirt system. It seems like there are a bunch of Jag guys out there that run it. It can control ignition too if you want to go that route. Just another option if want.
Could you P/M me a link to that site? ( P/M because its O/T here ) I'd like to read about that car some more...
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