ZF 8HP 70 box swap

[Fspp369]

Hello all,
I’m thinking of changing my 4sp with overdrive gbox,for a ZF8HP70.
I know that there are quite a few bits I’ve either got to fabricate or buy but I wonder if anyone has done this conversion here in the club.
The car is a V12 HE OTS currently in big pieces !!!.,
Any information about this subject is most welcome.
Peter.

[Fspp369]

I’m going for it with the ZF I’m planning to make the tunnel variation by removing the current tunnel down to the floor and from the bulkhead etc. would anyone be interested in the new tunnel fabrication as a set of pics or videos? Th box is quite large so the body G/B distance is my greatest concern.
I’d like to make a sort of “duplicate of the box” that I can haul it in and out all the time..any suggestions as to the material to make the “duplicate “.
Lastly, when it comes to prop shafts there are a few options. Any thoughts.
Several companies make quite a few bits but they’re all a bit of a compromise with regard to the body.
I’m tempted but maybe looking forward to the challenge when time is not too much of a worry.

[bitsobrits]

If your intent is to make a large part of the gearbox covering removable, keep in mind that is a structural part of the car and design accordingly.

[Fspp369]

yes noted thanks
I've been looking at the structure of the floor and bulkhead meeting....

[Fspp369]

Steve no I wasn't going to make the tunnel removable but wanted to make a panel shape that would allow cooling and ease of fitment/ service requirements.
I've been discouraged by the lack of information together with the thought of "butchering" my bulkhead.
Lots o people have put a v12 onto a 8hp70 but not apparenty a series 3 Etype !!!
Its still one of those on the table conversions .
Getting hold of a G\B is not a problem but that's as far as it goes...the car has a 2.88 diff already so it should be a nice drive.....???

[bitsobrits]

I would think the 8HP with its two OD gears (8th gear around .64 from Wikipedia) would be a step too far with a 2.88 rear end, yielding a 1.84 overall ratio in 8th. I think it rare to see a car with an OA ratio below 2, and there is a reason for that. You might find a car with the dynamic characteristics you seek that uses the 8hp and see what final drive they use.

As for making a mockup gearbox, styrofoam blocks can be glued together and hot wire carved and sanded into shape, then coated with epoxy resin (not polyester as it will dissolve the styrofoam!) and a layer or two of glass fiber to make it more durable. I used this method to make a plug mold for a gearbox cover in my Morgon 3W.

And these days you can have the 8HP scanned and 3D printed, no doubt at a higher price point!