Late TR7 Bellhousing

[Carboy0]

Question from ignorance for you owners of a modification bent? Seeing as the TR7 is really only half a Stag engine, will a TR7 5 Speed bellhousing mate up to a Stag backplate or adaptor plate without modification?

[Cleventry]

I have wondered the same thing and would be interested in an answer too. Seems like it would be easier and cheaper to locate an LT77 than an original 4sp O/D unit ?

[new to this]

I dont think it will, The LT77 Gearbox i think was the same as used on SD1 rovers the bell housing was different if using v8 to a straight 6

[Carboy0]

Yes you can see where I am going with this, TV8, TV8 backplate, TR7 2.0 litre 5 speed bellhousing and TR7 LT77 5 speed gearbox.

OR

TV8, TR7 backplate, TR7 5 speed bellhousing and TR7 LT77 5 speed gearbox.

The beauty is that the LT77 gearboxes have removable bellhousings, so you can mix and match, bellhousings and gearboxes.

I’m guessing everyone would know about it already if it was that easy.

[trunt]

I met a guy that was buying up any late TR7's just for the gearbox to convert MG's to RV8 engines.. so you may have something there..

Terry

[Carboy0]

Well I’ve just bought a TR7 5 speed bellhousing off eBay (now awaiting delivery). I already have a Stag manual gearbox backplate, so we’ll find out soon.

[Cleventry]

Thanks for the update. Be very interested in your findings. Years ago I rebuilt a sprint engine which has same block as a TR7. The sprint had a thicker steel back plate that bolted to the block that the gearbox attached to. I think the TR7 has a similar steel plate that attaches to the bell housing. I was thinking that TR7 steel plate might attach to the TV8 block and allow a straight forward add of the TR7 ( BL LT77) gearbox. But as you say if it was that simple you'd think that it would be more popular.

[Carboy0]

11B2D42C-FC1A-4BE4-84CE-08F30C705022.jpeg85C8B067-05AA-4294-AD8D-ECF0F7CDB4F7.jpeg9B7D878F-6705-445A-843B-C614E00D2CA3.jpeg8C01A95F-8349-428F-AD19-F09185C94A17.jpeg OK, I finally had an hour to check out whether this would work or not. Long story short, the answer is no.

the key issue is that the TR7 bellhousing has a smaller diameter than the Stag one, I guess because the TR7 has a smaller diameter flywheel.

Pics below. PS if anyone wants either part for their own project Message me as they are now for sale.

0FB0C143-1769-49F2-A5C6-2D0C547DE7DA.jpeg

[new to this]

if you want to fit a LT77 gearbox, your need a bellhousing from v8 SD1 Rover, but there hard to find now

[Cleventry]

Thanks for sharing the results.