[v12-engine] Turbo 400 vs BW12

V12-Engine
1

Well this might be useful information to anyone considering putting an
HE/Turbo 400 combo in a car originally equipped with a B12. The Turbo
400 appears to be in the neighborhood of two inches longer. Don’t yet
know if there is enough slop in the shafts to absorb the extra length or
not. Although I now have the tranny and the engine hooked up (PITA), I
have not yet slid the assembly back into the car. Tomorrow should be
interesting.–
Robert
73XJ12 (to be HE)
My Jaguar page at: http://members.home.net/obstinate

2

Putting the engine/gearbox combo back in is fun. Like I imagine giving
birth in reverse must be like. You need to get your lifting ropes the
right length so it goes in at the right angle (check Haynes/ROM for the
lengths. If you don’t have them, let me know). Also, once the rear of
the engine is close to the firewall you need to drop it slowly, and at
the same time raise the rear of the gearbox with a jack. The whole
assembly kind of pivots into place, and it the only way the sump will
clear the front crossmember and slot into place.

Good luck, and whoever you get along to help you push and heave to get
it aligned and shout “left a bit. right a bit”.

For me, that was my long suffering wife, and a girlfriend of hers that
was visiting.

Craig> -----Original Message-----

From: owner-v12-engine@jag-lovers.org
[mailto:owner-v12-engine@jag-lovers.org]On Behalf Of Cynthia Gonzales
Sent: 12 June 1999 06:59
To: V12-engine@jag-lovers.org
Subject: [v12-engine] Turbo 400 vs BW12

Well this might be useful information to anyone considering putting an
HE/Turbo 400 combo in a car originally equipped with a B12. The Turbo
400 appears to be in the neighborhood of two inches longer. Don’t yet
know if there is enough slop in the shafts to absorb the
extra length or
not. Although I now have the tranny and the engine hooked up
(PITA), I
have not yet slid the assembly back into the car. Tomorrow should be
interesting.

–
Robert
73XJ12 (to be HE)
My Jaguar page at: http://members.home.net/obstinate

3

Why change this way.
I was talking with an person from AJ6 the other week and he sayd that the
BW12 is more durable than TH400.
In the case that BW12 is functioning properly.

Any knollage on group?

Aleksi
1977 XJ-s with BW12----------

From: Cynthia Gonzales
To: V12-engine@jag-lovers.org
Subject: [v12-engine] Turbo 400 vs BW12
Date: 12. Juneta 1999 08:59

Well this might be useful information to anyone considering putting an
HE/Turbo 400 combo in a car originally equipped with a B12. The Turbo
400 appears to be in the neighborhood of two inches longer. Don’t yet
know if there is enough slop in the shafts to absorb the extra length or
not. Although I now have the tranny and the engine hooked up (PITA), I
have not yet slid the assembly back into the car. Tomorrow should be
interesting.

–
Robert
73XJ12 (to be HE)
My Jaguar page at: http://members.home.net/obstinate

4

I’m no auto tranny guru (anything but !) but that statement sounds a
little dubious, the GM400 is renowned for being a particularly tough
box, when set up properly it will stand up to a lot of hp (450+). I’ve
never heard the same said about the BW.

John

“Peltomaki Aleksi (NTC/Zurich)” wrote:>

Why change this way.
I was talking with an person from AJ6 the other week and he sayd that the
BW12 is more durable than TH400.
In the case that BW12 is functioning properly.

Any knollage on group?

Aleksi
1977 XJ-s with BW12

From: Cynthia Gonzales
To: V12-engine@jag-lovers.org
Subject: [v12-engine] Turbo 400 vs BW12
Date: 12. Juneta 1999 08:59

Well this might be useful information to anyone considering putting an
HE/Turbo 400 combo in a car originally equipped with a B12. The Turbo
400 appears to be in the neighborhood of two inches longer. Don’t yet
know if there is enough slop in the shafts to absorb the extra length or
not. Although I now have the tranny and the engine hooked up (PITA), I
have not yet slid the assembly back into the car. Tomorrow should be
interesting.

–
Robert
73XJ12 (to be HE)
My Jaguar page at: http://members.home.net/obstinate

–
This mail is a natural product. The slight variations in spelling and
grammar enhance its individual character and beauty and in no way are to
be considered flaws or defects.

5

John Littler wrote:

I’m no auto tranny guru (anything but !) but that statement sounds a
little dubious, the GM400 is renowned for being a particularly tough
box, when set up properly it will stand up to a lot of hp (450+). I’ve
never heard the same said about the BW.

John

I’m no guru either. I think I’ve probably heard about the same amount of good
press about both the BW and the GM, and little bad press about either. In terms
of durability that is. There are a lot more XJ-Ss with GM400s than with BW12s
out there, so you’d expect to hear more about the GM in general.

Negative commentary on the GM400 is almost invariably directed at its long
first gear. I haven’t heard anything said about the BW on that issue though.

How do the two compare, in the area of gear ratios? Anyone? I have a BW in my
car, so I’d love to hear that it has some little-known advantage :slight_smile:

Jason