[Lumps!] Need info on lumping an XJ6 with a TH400

Lumps
1

We raced our '87 XJ6 in the 24 Hours of LeMons in Omaha and
blew the head gasket. Crossing the finish line the temp
gauge was pegged out at 130+ degrees. Since we’re endurance
racing, we’ve decided not to chance this motor and
transmission any more. I have a 472 Cadillac motor and a
short-tail BOP TH400 that we’re going to replace it with.

Since Jaguar used the TH400 behind the V-12s, is the TH400 a
relatively easy swap into the XJ6s? Which tail do the XJ-12
TH400s have? Short, Long, or Cadillac? Are the crossmembers
the same? What are the differences in the XJ6 and XJ12
driveshafts? Does the shifter bolt right up or will I need
to re-engineer the linkage?

Thanks,
Erik–
EriktheAwful
Choctaw, OK, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

//please trim quoted text to context only

2

In reply to a message from EriktheAwful sent Tue 14 Sep 2010:

Erik:

Is there any on line footage on the Omaha LeMons?

130 F is cold, or did you mean 230 F or perhaps, yeah, 130C is aa
bit hot!!!

Johns cars offers a kit for the Big block Caddies into the XJ cars.
A tight fit likely, but doable.

The V12 Th400 is Jaguar specific. I’ve no idea as to tail shafts.

But, the trans mount is based on a flat steel plate for the GM to
Jaguar adaptations. Not too hard to cut one uot to fit the GM
rubber pad.

If the Cad engine mounts are up front on the block, it doesn’t seem
to big a task to transition to the Jag mounts.

It sure is going to be nose heavy, although the OHC is no light
weight.

The Jag shifter ends up close to where the GM unit is.

Andrew probably has a lever available to bolt right on.

One of the performance trans shops markets an infi nitely
adjustable lever that would likely do it.

Good luck with it.

Pics???

Carl–
The original message included these comments:

We raced our '87 XJ6 in the 24 Hours of LeMons in Omaha and
blew the head gasket. Crossing the finish line the temp
gauge was pegged out at 130+ degrees. Since we’re endurance
racing, we’ve decided not to chance this motor and
transmission any more. I have a 472 Cadillac motor and a
short-tail BOP TH400 that we’re going to replace it with.
Since Jaguar used the TH400 behind the V-12s, is the TH400 a
relatively easy swap into the XJ6s? Which tail do the XJ-12
TH400s have? Short, Long, or Cadillac? Are the crossmembers
the same? What are the differences in the XJ6 and XJ12
driveshafts? Does the shifter bolt right up or will I need

–
Carl Hutchins 1983 Jaguar XJ6 with LT1 and 1994 Jeep Grand
Walnut Creek, California, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

3

In reply to a message from cadjag sent Tue 14 Sep 2010:

http://www.murileemartin.com/LO10/LeMons_Omaha_10.html

Pictures 190-226–
EriktheAwful
Choctaw, OK, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

4

In reply to a message from EriktheAwful sent Tue 14 Sep 2010:

I suppose I should say we have a very limited allowable
budget, so a swap kit is probably out of the question. I did
email John’s Cars and asked for advice about the swap.

As far as fabrication goes, if we can’t handle it, we know
somebody who can.–
EriktheAwful
Choctaw, OK, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

5

Don’t hold your breath waiting for John’s Cars to respond to your e-mail! He’s famous for being uncooperative and unwilling to volunteer any information, even if you buy stuff from him.

I suppose I should say we have a very limited allowable
budget, so a swap kit is probably out of the question. I did
email John’s Cars and asked for advice about the swap.

//please trim quoted text to context only

6

FYI-

Look elsewhere- John’s has nothing for the Cadillac swap…

Andrew

//please trim quoted text to context only

7

I keep hearing that but for over ten years he’s never been anything but friendly and helpful to me…as a customer.

Bill
Alaska
'71 lump
'86 v12 vdPOn Sep 14, 2010, at 9:52 AM, crcote@mindspring.com wrote:

Don’t hold your breath waiting for John’s Cars to respond to your e-mail! He’s famous for being uncooperative and unwilling to volunteer any information, even if you buy stuff from him.

//please trim quoted text to context only

8

I had a customer call me just last week asking why the people at John’s were so cranky (and that’s not exactly the word he used- I cleaned it up some…)

Andrew

//please trim quoted text to context only

9

In reply to a message from A sent Tue 14 Sep 2010:

I dunno.

John, Mike and Bill helped me a lot by phone and FAX, not so much
so by e mail.

Some stuff not related to the kit I bought there.

Carl–
The original message included these comments:

I had a customer call me just last week asking why the people at John’s were so cranky (and that’s not exactly the word he used- I cleaned it up some…)

–
Carl Hutchins 1983 Jaguar XJ6 with LT1 and 1994 Jeep Grand
Walnut Creek, California, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

10

That’s the Market at work, Andrew!
Your reputation for help and service is excellent!

It will bring well deserved rewards

My response to the other post was out of a sense of fairness…

Bill
Alaska
'71 383 lump
'86 v12 vdPOn Sep 14, 2010, at 11:56 AM, A wrote:

I had a customer call me just last week asking why the people at John’s were so cranky (and that’s not exactly the word he used- I cleaned it up some…)

Andrew

//please trim quoted text to context only

11

In reply to a message from EriktheAwful sent Tue 14 Sep 2010:

Suncoast Conversions has a Cadillac swap kit.

http://www.suncoastconversions.com/--
lockheed 92 XJS Cpe/97 LT1 Miami FL/ 96 XJS Cv 4.0 Austin TX
Miami, FL, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

12

In reply to a message from lockheed sent Tue 14 Sep 2010:

John’s Cars emailed me back, and they don’t have any
knowledge about the Cadillac swap. He didn’t mention the
TH400 part of it and I’m not going to press the issue. I’ll
try calling Suncoast Conversions.

The hard part is asking these guys for tips and saying
there’s no way we can afford a swap kit with our
rules-limited budget, but we’re willing to put their website
on the car in exchange for advice.

I’m still looking for advice from anyone who’s swapped a
TH400 into their Jaguar.–
EriktheAwful
Choctaw, OK, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

13

In reply to a message from EriktheAwful sent Wed 15 Sep 2010:

Although I don’t have any experience putting a TH400 in an
XJ6, I have put a 4L80E in an XJ6. I am not sure, but the
outside dimensions/shape might be very similar. The 4L80E
is to the 4L60E/700R4 what the TH400 is to the TH350. It’s
bigger, stronger, and altogether different inside. With
that being said, my 4L80E fit (barely) in my 1985 XJ6. The
least room is towards the rear of the trans tunnel because
the 4L80E stays wider as you move towards the tailshaft as
compared to, say, a 4L80E. The most room is up front around
the bell housing and the front of the trans case.

Check out this link. It compares the 4L80E, TH400, and
4L60E/700R4. The Th400 looks a little more slender towards
the rear of the case.

http://www.hotrod.com/techarticles/drivetrain/gm_4l80e_automatic_transmission_review/index.html

The two tightest place on the 4L80E… actually the only
places causing me any problems, are the trans cooler
fittings and the electric solenoid plug on the right and
left side of the case respectively. I think the TH400 has
the cooler fittings towards the front of the case, and
definitely does not have the electric solenoid plug, so it
should not only fit but it should be easier.

Check out my webpage for more info. I have a technical
drawing of my 4L80E trans crossmember which needed minor
modifications to work.

-Dave–
The original message included these comments:

John’s Cars emailed me back, and they don’t have any
knowledge about the Cadillac swap. He didn’t mention the
TH400 part of it and I’m not going to press the issue. I’ll
try calling Suncoast Conversions.
I’m still looking for advice from anyone who’s swapped a
TH400 into their Jaguar.

–
1985 XJ6 LS1 - For pictures go to www.buyrcars.com
Pittsburgh, PA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

14

In reply to a message from EriktheAwful sent Wed 15 Sep 2010:

Well, I didn’t swap one in, but I did pull one out…

I’ll be honest and say that I didn’t pay that much attention when I
removed the 350/TH400 (not the usual TH350) from my ‘parts’ '86
XJS, but I’ll tell what I remember.

This had a short tailshaft TH400 (out of a truck?) with a
conventional slip yoke, the rear crossmember didn’t look much
different than the one in my '83 ‘John’s Cars’ swap, and I don’t
remember anything ‘special’ being done with the shift linkage. It’s
my understanding that the internal bits on the Jag version of the
TH400 are pretty much the same, so maybe it’s possible to swap the
shift arm between them. The driveshaft appeared to be original
except for a standard GM front slip yoke; they simply ‘adjusted’
it’s length then welded the OEM rear slip joint. Must have worked,
as the car had traveled about 60K before succumbing to bad
electrical/neglect.

This wasn’t a ‘kit’ swap, as the motor mounts were obviously home-
built and welded in. The engine/trans were both sold, so I can’t
tell you any more than this…–
The original message included these comments:

I’m still looking for advice from anyone who’s swapped a
TH400 into their Jaguar.

–
Steve Ellingson '83 XJS V-12, '83 XJS LT1, '86 XJS parts,
Yelm Washington, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

15

Erik…I’m on the edge of this…I have a lumped XJ6 (383/ 700R-4) that was installed with a John’s kit around ten years ago.
Too much power and i broke the 700 and i want to put in a turbo 400 (If I fix the 700 it will be third time; not gonna do it).
I talked to John and he has the stuff to make the 400 drop in to replace a 700-R4 (SBC, not jag engine, remember!) and right now I’m scanning the junk yards in Alaska so I can put one in to try it out…I need my money other places for now.
Yes, short-tail is right

ALSO I have an '86 V12 vdP (Canadian Car)…When i got the car, I had to overhaul the th400 that is the tranny that comes in the car…idle too high and it didn’t help the tranny.
They are NOT the same as the regular 400; it’s the bolt pattern.
They bolt up to a RR or a Landrover or a jag V12 or a Ferrari…but not to a chevvy…and not to an XK engine.

John’s Quarterbreed kit is to put a 700-R4 into a v12 jag.(I’m leery of that but see many posts that tell me it is a matter of building up the 700…pretty expensive…I don’t mind RPM’s and don’t like lugging…so I’m sticking with the 400 (" Bullet-Proof" is what the overhaul shop said.) and would like to end up with one in the S. One too

I don’t have answers for you …but trying to get you on the right path…maybe there are some answers here.
Have you called Andrew and discussed all this with him?

Since even the Series Ones could come either V12 or straight Six Fitting the car does not seem to be the problem…(springs etc. are something else)

Maybe this will help you…

Bill
Alaska
'71 Lump
''86 V12 vdPOn Sep 14, 2010, at 6:52 AM, EriktheAwful wrote:

I have a 472 Cadillac motor and a
short-tail BOP TH400 that we’re going to replace it with.

Since Jaguar used the TH400 behind the V-12s, is the TH400 a
relatively easy swap into the XJ6s? Which tail do the XJ-12
TH400s have? Short, Long, or Cadillac? Are the crossmembers
the same? What are the differences in the XJ6 and XJ12
driveshafts?

//please trim quoted text to context only

16

In reply to a message from William de Creeft sent Wed 15 Sep 2010:

Interesting article to me since I have/had Jags with all (4) trans
and V8’s. Never had any trouble with any of the GM trans models.
The 700R with the LT1 is stock from 1993 without any known history
and was supposed to have about 50K miles on it. I have put another
5K miles on it and it is working fine.

Currently driving (2) 700R’s, one with 383 and other with 350/LT1
and my favorite S1 with the 200R and with the most powerful 383.
The 350 is in my parts cars (305/350) and worked when we drove onto
the tow truck to get it to my house. The whole car will be sent to
the wrecking yard soon with the engine/trans 90% intact.

The 400 I took out to replace with the 200R and it is working in my
neighbora '52 Chevrolet truck with a built 350.

None of the cars have been driven ‘‘carefully’’ and all but the LT1
have big B&M trans coolers (it’s is on the floor waiting for me to
have the time to install it with proper lines).

It is my opinion that any of the GM trans will last behind a V8 if
built up by a competent shop and is serviced reguarly.

Going ‘‘backwards’’ to a 400 from a 700R does not make sense to me.
Get your 700R rebuilt by a good place like BowTieOverdrives or TCI.
It will last longer than the rest of the car.–
The original message included these comments:

Too much power and I broke the 700 and I want to put in a turbo 400 (If I fix the 700 it will be third time; not gonna do it).

–
'71 XJ6 383/200R, '72 XJ6 LT1/700R,'74 XJ6 383/700R
Glendora, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

17

Thanks,Roger.
I’ll check into BowTie and TCI but it’s a matter of money for now.
I just moved the car yesterday from one barn to another…it clanks and rattles in ‘second’ and slips if it kicks down climbing a hill.
Otherwise it drives down the road fine.
I was going really hard in lower range (youthful exhuberance at 78 years old…but that’s supposed to be what you pay for )and rattle showed later up poking around town in lower range.

First time it broke was probably the “lock up” and it was 6000 miles from home and only " @@mco" available to get underway with wife and dog = $2200 (but cheap when you figure up motel costs).
I would love to find out it’s a simple(cheap) repair, but there’s nobody in this town to take it to, so that makes it a big deal.
If I could drop in a used (cheap) 400 I’m advised thats what i want, to be able to use the car…not planning any long road trips.
I’m listening to you, and I’ll sit on it…I’ll get some prices but have got to get it past Accounting (wife) and I’m retired and never have money riding around in my pockets anymore.
Difference seems to be between “less than $1000” and "more than $2000 " (and must be done right !)
(For that kind of money I could ship the v12 to a real mechanic and get the wiring sorted out …)

I mostly was answering the “will it fit in the car” question and the issue of bolting it up…forgot he’s talking about swapping to a caddy engine first…that would do it.
But the 383 goes really good…

Thanks for the time,Roger…

Bill
Alaska
'71 Lump
''86 V12 vdPOn Sep 16, 2010, at 3:20 AM, Roger Mabry wrote:

In reply to a message from William de Creeft sent Wed 15 Sep 2010:

It is my opinion that any of the GM trans will last behind a V8 if
built up by a competent shop and is serviced reguarly.

Going ‘‘backwards’’ to a 400 from a 700R does not make sense to me.
Get your 700R rebuilt by a good place like BowTieOverdrives or TCI.
It will last longer than the rest of the car.

The original message included these comments:

Too much power and I broke the 700 and I want to put in a turbo 400 (If I fix the 700 it will be third time; not gonna do it).

–
'71 XJ6 383/200R, '72 XJ6 LT1/700R,'74 XJ6 383/700R
Glendora, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

//please trim quoted text to context only

18

In reply to a message from William de Creeft sent Thu 16 Sep 2010:

I called Suncoast a few minutes ago. It sounds like the
conversion is pretty straight-forward except that the engine
mounts are a pain. We might end up buying the motor mount
adapters. Unfortunately our build doesn’t have a whole lot
of wiggle room, and a lot of our money is going towards
safety gear.

As far as the transmission tailshaft and driveshaft are
concerned, he says it doesn’t matter which tailshaft you
have, you have to get the driveshaft modified to fit. The
transmission crossmember is also a custom job, but it
shouldn’t be too hard for us to make one.

The shift linkage doesn’t just bolt up, but usually that’s
just a matter of lengthening or shortening the throw on the
end of the linkage, so we can sort that out ourselves.

I think once I get the old motor out I can make a mock-up of
the Caddy and we can start doing our trial-and-error work.–
EriktheAwful
Choctaw, OK, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

19

In reply to a message from EriktheAwful sent Thu 16 Sep 2010:

Eriktheawful:

Yup, I was wrong, it was Suncoast that offered something for the
big caddys.

Jim, John and Andrew were all involved in some way in my lump. Good
guys, all of them, in my eyes.

Good luck.

Too bad you are so far away, I’d like to play with the lump you
remove. No scratch that, what am I saying!!!

But, it with blown gasket and all may be better than some of the
engines some of the guys are trying to nurse along!!

Carl–
The original message included these comments:

I called Suncoast a few minutes ago. It sounds like the
conversion is pretty straight-forward except that the engine
mounts are a pain. We might end up buying the motor mount
adapters. Unfortunately our build doesn’t have a whole lot
of wiggle room, and a lot of our money is going towards
safety gear.

–
Carl Hutchins 1983 Jaguar XJ6 with LT1 and 1994 Jeep Grand
Walnut Creek, California, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only

20

In reply to a message from EriktheAwful sent Tue 14 Sep 2010:

A short-tail Th400 will fit no problem in a series 1 chassis, even
with extreme engine set-back. I have a soft spot for those
trannys - ran one in my 461BBC turbocharged XJ s1 race car and it
was pretty reliable, although I did tear the input shaft out of it
at one stage, and keeping the high gear clutches alive in a very
high torque application took some modification. As for weight - my
race car had 53/47 F/R weight distibution, and weighed 1622kgs,
even with a big block and all the turbo stuff on it. Only real
weight saver was a carbon fibre hood, and a stripped out interior -
otherwise it was all steel and glass.

Cheers, Andrew Robertson, New Zealand.–
The original message included these comments:

transmission any more. I have a 472 Cadillac motor and a
short-tail BOP TH400 that we’re going to replace it with.

–
Andrew Robertson
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

//please trim quoted text to context only