Z-TARD Posted November 15, 2001 Share Posted November 15, 2001 I think I've had an epiphany, or maybe just a brain embolism.... I came across a Jaguar XJ12 while I was searching in a junkyard for a decent SBC to rebuild. I pretty much abandoned the idea of using a V-8 as soon as I saw the V-12 in the Jag. Has anyone done this conversion yet? I realize that it wont be nearly as cost effective as using a chevy motor, but I still think its worth a try simply for the "ooooooh...ahhhhhh" factor. The main problem I see right now is that aftermarket pistons are not available in oversize.This is due to the engines aluminum construction, when its time to replace the pistons, you replace the cylinders as well. I just cant seem to find cylinder liners anywhere on the internet though. So I plan on finding pistons from another manufacturer that are slightly larger than the Jag pistons (90mm), and boring out the liners to match them. I'm still researching it at this point, but I think I can make it work......maybe. I also plan on scraping the fuel injection setup because its probably to bulky to fit in the Z engine bay. I'm going to try the extra complicated route and try to mount 12 individual carbs, most likely from an as yet to be determined motorcycle engine. Probably just an embolism...... Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 15, 2001 Share Posted November 15, 2001 People swap out the V12 to put in a Chevy V8... Much cheaper and more reliable, not to mention more powerful (potentially. It would cost you a fortune getting everything to fit, let alone making it work. If you are intent on shoe-horning a V12 in the Z why not stick a Mercedes 6L V12 instead? Shouldn't cost much more considering it wouldn't need a rebuild. More power and reliability too... Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 15, 2001 Share Posted November 15, 2001 Yeah or the BMW V12 w/5sp auto out of a 7 series. Make a nice swap, but just like the jag VERY expensive. Might be tight though, havn't seen one of those (the $97,000.00 pricetag on the showroom floor kinda stopped me from flipping the hood open.. ). Regards, Lone Quote Link to comment Share on other sites More sharing options...
staledale Posted November 16, 2001 Share Posted November 16, 2001 Got a Jag with my last Z car. I's sitting on the floor next to it. It can be done, but.......it's to heavy, to big, and way, way to expensive. Fuel inj. won't fit between shock towers, Carbs(6x2 webers) will sit ya back the price of a great sbc. I don't what to talk you out of something, but I finally talked my self out of it and I've got the whole drive train sitting here. That IRS is another story. got web sites on Jag if ya want them. Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted November 16, 2001 Share Posted November 16, 2001 QUICK SOMEONE CALL 911, Z-Tard is having a Stroke! Seriously tho, if that is where your heart is pulling you then by all means, go for it. I just feel you're biting off an awful lot & the bites your getting will be from a pretty expensive apple. Good luck. Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted November 16, 2001 Share Posted November 16, 2001 Use the search, this has been discussed before and th econsensus as I recall was that parts are VERY expensive. Jags aren't exactly known for high reliablity either. It would look really cool mind you but if it drove you into the poorhouse... Quote Link to comment Share on other sites More sharing options...
Dp351zcar Posted November 16, 2001 Share Posted November 16, 2001 Yes these all good points but have you ever heard a V12 run (lightly muffeled) though the gears. They sound great. Don Quote Link to comment Share on other sites More sharing options...
fl327 Posted November 16, 2001 Share Posted November 16, 2001 like a big motorcycle.... Quote Link to comment Share on other sites More sharing options...
staledale Posted November 16, 2001 Share Posted November 16, 2001 http://www.ontariozcar.com/zedline/2001/mayjune01/mayjune07.htm Here a site for the Jag V-12 in a Z Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 16, 2001 Share Posted November 16, 2001 The V12 is actually a very strong and durable engine. It gets replaced because old Jags tend to fall into the hands of people who can't or won't pay to maintain them, for there is a lot of complexity to the subsystems. Probably due to the high depreciation. :^( From a price/performance standpoint, a Chevy V-8 is by far the best option. But if you can afford it, the Jag V12 would be cool. I don't think it is as expensive as a Mercedes or even a BMW V-12. The Jag V12 was produced for over 20 years, put in a lot of cars, and there are a lot of places to buy parts from. Still, it's much more expensive as a American V-8 to rebuild. It is really huge and heavy for an all-aluminum engine, but that's because it has a ridiculous amount of displacement growth room in it. It can be enlarged to 7.4 liters with little trouble (not cheap though!) because the bore centers are so far apart. With more effort, it can be pushed to 8+ liters, and it still isn't as tricky, as, say, stretching an LS-1 to 427 cubes. If you keep it stock, it produces anywhere from 285-313 HP net (5.3 liter-6.0 liter), which you can easily outdo with a Chevy V8, but the Jag engine will be super silky smooth (perhaps not that important to most hot rodders though), and have that glorious V12 sound. And it is not even close to its limits (6500 RPM redline.) The stock valvetrain was designed to go to 8000 RPM, but the stock ports, intake, and cam were optimized for smooth luxury duty and low-end, so there was no point in going that high. Again, from a cost standpoint, there's no comparison, but there are many cool things to recommend a V12 swap. If you were building a 250GTO replica, this actually would be the cheapest way to get a V12, as the original had. DLY Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted November 16, 2001 Share Posted November 16, 2001 Toyota makes a v12 5.0 48 valve in there domestic market. Its pretty hard to find inf. on it though. It is in there domestic market CENTURY a barge if there every was one. Power is capped at the jap standard max. of around 280 hp. Douglas Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 16, 2001 Share Posted November 16, 2001 Does anyone know the layout of the jag V12, it almost looks like two sixes siamesed together. Narrow angle V? I'm sure the sounds are REAL sweet. Looks heavy, be nice in aluminum.. Regards, Lone Quote Link to comment Share on other sites More sharing options...
staledale Posted November 16, 2001 Share Posted November 16, 2001 Quit playing with my brain cell. Got one and most of the time it's out looking for a friend. Went out to check on lay out for Lone and started checking for fit again. LoneHD it is a 60 degree lay out. Now it is 36 inches long with no fan. The Z is 40 inches firewall to core support without rad. Fuel inj. is 31 side to side without air cleaners. Strut towers are 31 apart. If ya go carbs, ex manifolds are about 24- 25 inches and a little above frame rails. That would be no problem. So where can I get 6x2 webers that I can afford? It would also be tall with the webers. I've got to "just say NO" but it would sound sweet. Quote Link to comment Share on other sites More sharing options...
Guest Thurem Posted November 16, 2001 Share Posted November 16, 2001 There is a site where they put T5 transmissions behind jags for racing I think it's 5speeds.com. just a thought. Thure Quote Link to comment Share on other sites More sharing options...
DavyZ Posted November 16, 2001 Share Posted November 16, 2001 Thure, the guys at gearzone.net raced Jags--they developed the T5 internal balancers, etc. Davy Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 16, 2001 Share Posted November 16, 2001 There's about 4 or five tranny's they put behind them (or should I say, can put behind them). The T 5, A rover transmission, a ZF transmission, toyota supra with an adapter, and they may have tried the T56 and possibly tremec's. Theres a site specific to jags that talks about each transmission and its pluses or minuses in the jag. This isn't a swap I'd do (thanks for the measurements though, its gotten asked here several times). To long, to heavy. I suppose if a guy were going for a luxury cruiser and handling and weight were secondary, it'd be nice to see a z decked in connoly leather with lots of sound insulation and sporting a 12 banger. Find your ascot and go motoring in style--British old school style. Roll up on ya pardner, "Yo homie, you got any grey poupon?" Regards, Lone Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted November 16, 2001 Share Posted November 16, 2001 What about a set up with 3 small holleys or mabye 6 two barrel ones. Someone must have done this buy now. Webers are two damn expensive. Which brings me on to the next subject. Has anyone seen a 4* 2 barrel holley setup for the domestic v8? Douglas Quote Link to comment Share on other sites More sharing options...
SpeedRacer Posted November 17, 2001 Share Posted November 17, 2001 I haven't seen a seen a 4 X 2 barrel Holley setup but Mickey over at Inglese has a 4 X 2 Weber setup for a SBC http://www.inglese.com/ I think they are Weber IDF carbs (just like Ferrari) and the four of them are lined up right down the middle of the manifold. This doesn't leave enough room for the distributor so you have to use an angle drive or front mounted one. BTW, etype - there is a guy in Flordia that has a Ferrari 250 GTO replicar with a Jag V12 in it. The is also a guy in CA that has a real Ferrari V12 in his 250 GTO kit car! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 17, 2001 Share Posted November 17, 2001 Maybe four sets of those three bbl weber's like they used on the 911's. No doubt it would be eyecandy to say the least being a V-12. Regards, Lone Quote Link to comment Share on other sites More sharing options...
Z-TARD Posted November 17, 2001 Author Share Posted November 17, 2001 Going to pick up the V-12 tommorow hopefully, found one in "Pick a Part" junkyard, and if the prices listed on their price sheet are correct, it will set me back about $150 for just the engine. It has a GM 400 tranny on it now, I think I'll try to grab that too. Eventually I want to put a T-56 on it though. I'm also considering modifications to the fuel injection intake runners to move them to a more vertical position to get them out of the way of the strut towers. I got my JTR manual in the mail a few days ago. The SBC is still in the back of my mind, but the voices insist that I go with the V-12, and I dont want to make the voices angry........Does anyone know of an engine that uses pistons that are around 3.537" or 91mm bore? If I bore out the Jag cylinders this is the size piston that I'll need to move up to. I think I can, I think I can... Quote Link to comment Share on other sites More sharing options...
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