So I have searched a bit and read some threads. There must be a manual trans that bolts up to the v12 that isn’t worth more than the car ? I know there are kits for around $6k is that the best I can do ?

 

Simply Performance has a Getrag 265 kit that comes in about $2900 plus shipping. Had I known that a bit sooner, I wouldn't have wasted money rebuilding my TH400.

https://simplyperformance.com/wp-con...elist-2018.pdf

 

England or America?
How much work are you ( not a hired mechanic) going to do?
Can you drill holes in Aluminum? Do you know how to tap a hole for threads?

 

[QUOTE=Mguar;2250609]England or America?
How much work are you ( not a hired mechanic) going to do?
Can you drill holes in Aluminum? Do you know how to tap a hole for threads?[/QUOTE

I am in the US and will do all the work myself.
the simply Performance kit looks to be the most affordable but I am wondering if there isn’t a less expensive option for the diy types.

 

Oh yes. Go find a good used T5 or T56 behind a V8 Chevy. I picked up my T 5 for $500. The locating dowels align everything but it will be about 3/4 of an inch too close. So buy a plate of aluminum (shouldn’t cost much over $40-50) whatever thickness you need. It will vary depending on what transmission you get. Drill two holes to line up with the locating dowels.
You’ll need transfer punches to locate the holes in the aluminum plate. Shouldn’t cost you much over $30-40. Drill out the holes and counter bore them for the tapered Allen head Bolts .

Using the locating dowels transfer the bellhousing bolt holes to the same plate. Drill and tap those holes.
Yes you will need a flywheel. Pressure plate and clutch disk You can either use an old Jaguar used one one or buy one of the aftermarket ones ( I use Tilton 7&1/4 triple disk for the race car. And the AT flywheel for starting. You will also need a center release throw out bearing Plus a $5 throw out bearing opened up to the size of your pilot shaft. ( machine shop work.)
Youll have to figure out the trans mounting yourself. As a racer I mount both the engine and transmission rigid. You don’t want to do that for the street.
plus once everything is in place measure the distance from the end of the transmission to the mounting plate for the driveshaft on the rear end. Bring that and your driveshaft to your local driveline company. Figure less than $100 To have your driveshaft modified to work. depending on how good you are at scrounging. $2000-$2500 should cover it.

 

I changed my 91 12cyl over to manual about 9 years ago. I went with a Drivenman kit Tremic TKO 600 5 speed. The extra's were Fidanza aluminum flywheel, Zoom 10 1/2" clutch & gear reduction starter. I think that much was around $6K. I needed to send my ECU over to AJ6's Roger Bywater to have it reworked in order to correct the stalling issue between shifting of gears. Around $400 with S&H to the UK. Yes there very expensive even doing the work yourself.

 

So it’s sounds like a budget method is possible just need some patience and hard work of coarse.
the simply performance kit seems like the most reasonably priced kit. I sent an email but no response. They may be under lock down not sure.

 

My experience is most are very independent Co's. A whole other thread subject. Anyway it's all about what your budget will buy & what components you want to use in the conversion. If you want all new 5 or 6 speed Richmond or Tremec expect around $3k, 6 speed ?more$$, (do you need two overdrives as with Tremec 6sp) . Aluminum flywheel & HD clutch around $500+ but not necessary. IMO you better know what your doing if you buy your components separately, new or used vs a kit.

 

I know in cdn dollars its very expensive for the kits. It would be cheaper to put a v8 and 5 spd then do a conversion. Lol. But i search everyday for a tranny that may pop up for sale. Until then the th400 cane be molded to be a 3spd manual..just no clutch....and is proven strong when built right. And the v12s don't produce enough power to get into expensive internals.

just imo. 5spd would be cool but I'll probably do an engine swap before just a tranny swap.

 

If you want a V8 car, why don't you just buy a Corvette? Or a Camaro, or a Mustang? It will be easier and probably cheaper.

I bought the XJ-S for the V12 engine. Not really seeing the point of getting the car in the first place if you're going to swap to a different engine.

 

Why would you want less power than our V12’s make? A 1980’s Chevy 350 makes 160 horsepower SAE net. Compared to our 5.3 V12 which has 264 DIN ( multiply DIN horsepower by 1.0139 to get SAE horsepower )
That’s right, Jaguar makes more than 100 horsepower than Chevy.
now later Chevy’s had 190 horsepower. ( still less ) but along about then Jaguar came out with the 6.0 V12 that had 314. DIN

 

If you think a manual transmission kit is expensive try the cost of an engine and transmission swap.

Plus you will wind up with less power. A lot less!!

No a Chevy 350 Doesn’t have 350 horsepower that’s the engine’s size in cubic inches. A 1980’s spec 350 makes 160 SAE horsepower to the Jaguars’264 DIN horsepower. In the 1990’s the 350 made 190 horsepower. But by 1992 the V12 was up to 314. ( to get SAE horsepower from DIN multiply DIN times 1.0139

 

There's a 2008 Corvette LS3 with a six speed on Sacramento Craigslist with under 100,000 miles, asking $18,600, which gets you a very nice, but stock XJ-S. Google tells me the Corvette came with 430 horsepower that year. Like I said, if a V8 car is what someone is after, starting with an XJ-S doesn't make much sense.

 

Yes I know my engine sizes. I have built a few v8s from the block up.

The conversion kits to go to manual that some companies make after exchange rates and shipping are around 7k to 10 cdn.

who in their right mind would put in a stock v8 from the 80s? Absolutely no one lol.

I actually think a diesel powered xjs woukd be sweet.

Or a awd v6 with a twin turbo.

 

I think you guys misreading what I said.

I never said I was swaping the v12 for a v8.

I said the cost.of buying one of those kits from a company is actually more expensive (exchange rates, shipping, and taxes then if i locally sourced a v8 (or even modern v6s) and tranny together.

 

So did I.

But if the v12 dies for some reason would i put another v12 back in? No I wouldn't.

 

Simply Performance recently quoted me GBP 3,571 for a complete kit to do the conversion (including wood ski slope) plus GBP 395 for shipping to Ohio not including import duties (if any). So $4,950 all in -- not including labor to install.

 

I looked into the Simply Performance kit a while back and it looked like a good option. I assume the amount he quoted you included a Getrag 265 gearbox?

 

Correct

 

Okay, that makes more sense. I kind of like the diesel idea. Would a Cummins B-Series fit? I'm pretty sure you could stuff in a Daimler-Benz OM606 with a 603 injector pump, re-educated in Finland. With a big turbo and an intercooler you can get 400 reliable horsepower, better fuel economy and some wicked turbo-diesel sound.

I was wondering about shipping. Overall cost is a tad more than I estimated, but I wasn't going to get the ski jump. This guy I know from the Navy Reserve* started a job at a rod and custom shop not long ago. I should talk to him some more. He's already willing to rebuild my V12 if I manage to grenade it.

*I have the Navy convinced that I'm a diesel mechanic (https://en.wikipedia.org/wiki/Constr...ed_States_Navy)), but I'm not really all that good. This guy is freakin amazing.