New guy on the forum from high desert in CA (China Lake area) starting a fun restoration/upgrade project.

Have a very pristine 1972 XJ with a very dead XK engine and just obtained a pitifully cosmetically clapped out '95 Vanden Plas with an amazingly good AJ16 engine and -24 ZF transmission...actually all the mechanicals on the '95 car are quite good.

Guess I should add that, since I'm new here, if this is like an NCRS group of Corvette enthusiasts you should probably quit reading now because what follows will likely irritate you.

The plan is to transfer the AJ engine, transmission and minimally necessary computer/electronics from the '95 into the '72. I've done this type of project before with domestic cars but the Jag is relatively a new set of detail problems.

Luckily I have a good friend here who is also semi-retired who has years of experience as a chassis and engine fabricator for several GTP race efforts who will be helping me.

Know from other auto experiences that getting active on an enthusiast forum is a great source of knowledge support. Would really appreciate any thoughts/experience on interfacing with the '95 ecu/computer.

Our biggest drawback is that we're old enough to be primarily carb oriented. Remember, since this is going into a '72 car I have a pretty free hand on setting up the car....even in Kalifornia, but I would like to keep the fuel injection system.

Also have a weath of computer engineer talent to work with who work in the area (sadly, none with Jag experience).

Look forward to sharing the trip.

 

Sounds great to me :-)

Cheers
DD

 

I will be watching this with a lot of interest.

 

Sounds interesting...........

 

After much deliberation over the pros and cons of a high pressure fuel system and the computer required to make this project work, a decision has been made to drop the AJ16 transplant and make use of a very pristine 5.3 L V-12 and tranny that is laying around the shop and converting it to 4 Weber 40 DCOE carbs. Have a good intake manifold for the conversion and decided that almost any mechanical issues involved here would be easier for me to deal with than computer problems.

 

skip the v12, its heavy, under powered and inefficient. when you tally up all the parts you are going to need it will cost too much in time and money. im a proponent of the chevy conversion. the gen1 sbc chevy with carb and 700r4 trans will make it a great road going car over all. if you want the refinement of computer control then go with an lt1 and 4l60e trans controlled by a integrated pcm. there are plenty of chevy caprices, and other full sized GM cars that can be bought for cheap and then you will have almost everything you need to do a transplant. i have a 75 xj12, had an 86 xj12 and prenenty have a xjc with a gen1 sbc 400. you can find videos on you tube.

 

I considered the SBC early on and decided that was not the way I wanted to go. I already have all the parts I need for the V12 conversion and I really don't buy into the argument that an all aluminum SOHC V12 with no emission requirements/equipment has to be any less efficient than a cast iron block push rod V8 of roughly the same displacement. I will be using the Jag version of the 480LE trans though.

 

First of all, I have a healthy respect, bordering on awe even, for those with the skill to do drivetrain transplants. Very cool stuff.

That said, the inline 6, and especially the V12, are just such integral components of the entire Jaguar experience, that replacing them with a commonplace engine just seems criminal. I understand if you have a modern BMW or Mercedes V12 + transmission available (they can be found dirt cheap as well), and you want to make a project of that. But a small block chevy - WTF?

The sound is wrong, the power delivery is wrong (where is my waftability, my turbine smoothness, my passing power at 100+ mph), the aesthetics are wrong.

If you have to substitute, make it a worthy swap, for ****s sake.

Tacamo, just saw your update, and see that we are on the same page. Godspeed.

Also:

 

I liked your first idea of the modern Jag engine and FI. I have no use at all for their early V12 engines... Fortunately CA does not care what you do with your S1 for smog reasons!

By changing the S1 gas tanks to S2 or later you can gain the needed return fitting. I have pictures and the needed parts to add a (6) port fuel switch and the lines required. Getting rid of some or most of the old Jag stuff and replacing with modern equipment is the way to go.

These early short wheelbase Jags are attractive and fun to drive with some improvements. Ditch the school bus steering wheel!

My 1972 XJ with LT1/700R is running fine now and all the bugs have been
worked out.

Making the Series 1 XJ AC and heating work is fun, but again it has all been done before. Making the Jag computer(s) work should not be hard as we have discovered all the GM problems.

Having two S1 XJ Jags, I have had to do pretty much all that is ever done to get these old cars in great shape. Currently changing the front stub axles for the wear just discovered that I thought was front bearing noise.

Contact me for access to my pictures etc. mabryroger@hotmail.com

 

While I'm using an early 5.3 "flathead" V12, I'm not using the fuel injection. I have a set of XKE intake manifolds which will be modified to accept 4 40/45 DCOE webers. The GM tranny will require a stand-alone module to make it work but I have already found at least 3 companies who make such a unit. Much more flexability than existed with the ZF I planned to use on the AJ16. I agree with the wheel comment. The car has a beautiful Nardi already installed.

 

As of tonight I have the XK engine and BW slush box out of the body. Will be doing an initial insert of the 5.3 L and 4L80E in the next day or two. It's obvious that the 4L80E is a little longer than the BW but right now it doesn't look like that will require anything more than moving the transmission X member a little further aft and shortening the forward drive shaft. Love those DCOE's on the XK. The four DCOE 40s should look equally good on the V-12. The '75 V-12 radiator (much more cooling capacity than the original in the '72) dropped right into place and will require no apparent mods. Lots of grunt work now to remove trim/lights for the eventual re-paint. Everything needs to be scrubbed out in the engine bay and the chassis even though the car was pretty clean to start with. NO RUST! Have bushing kits ordered to upgrade the front suspension and steering rack while the engine is out. WOW! Good sign/omen. Just became a Grandpa for the second time. Two grandsons now.

 

Hit the first real speed bump in the project last night. The bellhousing bolt pattern on the 95 (6.0 litre) block 4L80E is simply no where close to the bolt pattern on the back of the 5.3 Litre. Had really hoped that at least 3 of the holes would line up. Right now it looks like the easiest fix is going to be to get/make and adapter plate to mate a Chevy 4L80E up to the block which will simplify hooking up a stand alone transmission controller and offer a mechanical speedometer port as well. In theory, a large Chevy bellhousing bolt pattern is the same as the 4L80E. Found an adapter on a commercial Jaguar specialty web site but was shocked that they wanted almost $500.00 for it. Any thoughts. suggestions or experience out there?? No, I'm not going to put a Chevy engine it. How about a blue print with the engineering dimensions ofr the back of the 5.3 block?

 

I know how you feel I've been there. John's cars sell a conversion kit too (795$) Would you Consider a 700R4? No computer necessary (save 500$ right there and you wont need to wire up a TPS) and I believe the ratios on the 4l80e are not ideal for the V12. The 4l80e wont fit without consderable modifications to the trans tunnel. The 700R4 will fit with only minor mods. The shorter 1st gear on the 700R4 will get that big v12 spinning in its power band much sooner. The 700R4's taller 4th gear will offer great highway cruise RPM with your rear great ratio too.

Have you seen this thread?
GM bellhousing bolt pattern dimensions - HybridZ

 

Thanks for the info....how much of a problem was it to get the mechanical cable hooked up for downshifts and lock up? Having a purely mechanical trans has some significant advantages.

 

Lockup should be accomplished electronically. You can use a kit for this from B&M which has a cable based speed sensor. Some trans builders rework the valve body to always lockup in 4th gear using no electronics but that's not ideal IMHO. You should also use a Corvette or Z28 governor in the 700R4 so you get a 5500 RPM shift point at WOT. If you want a purely mechanical trans you'll have to go with a TH350. It uses just a vacuum signal for modulation and a cable for down shifts.
You'll need some basic fabrication and welding skill for the cable bracket in either case.

 

Back home again....thanks for the 700R4 info. I don't have any issue with using that trans. Actually, the fewer electronics on this conversion, the better. Is the cable based sensor you mention the conventional speedometer cable? I also assume that there is a "kick-down" cable from the throttle linkage. Did a little research on line last night and it looks like there is a 31 spline input shaft that is preferrable and the Corvette/Z28 governor is good info. Thanks.

Still looking for a blueprint of the backside of the Jag 5.3 L for making up an adaptor plate to hook up with the large bellhousing Chevy bolt pattern.

 

Anyone running a MSD or other ignition box on a 5.3 or 6 litre 12?

 

ICSAMERICA- bought the kit from Johns to install the 700R4. Have a rebuildable trans in hand too. Have studied the hookups and now understand the TV cable + it appears that the speedo is pretty much a direct hook-up with the parts in the kit. We probably would have gotten the spacers, etc. right eventually but having the benefit of someone who has made the swap before is comforting. Still need to confirm the engine mount location between the XK and the 5.3 is about the same in the chassis...will do a mock-up mounting as soon as I get the engine/trans adapter. Thanks for the suggestion.

 

Engine snob!!! j/k

BTW, my LS1 XJ6 pulls great at 100mph!

 

Have the 700R4 rebuilt and the entire front suspension including all bushings, ball joints, bump stops, sway bar mounts/bushings and steering rack bushings replaced. Still waiting for the adapter kit from Johns to begin the trial engine/trans fitting. Removed the front and rear glass and was most pleased that there was no rust in the channels. Car is virtually rust free! Hope Johns come through soon so I can finalize the engine and trans location in the chassis and start rebuilding the 5.3L before Christmas.

The car is a grey or silver color but I can't find a paint code anywhere on the body...any help?