Diesel gearbox on a petrol engine

[MaxRothery]

Hey all

I'm looking to do an engine swap into my Triumph and I've hint it down to a 2.5/3.0 jaguar V6 petrol. Unfortunately, I can't find many manual gearboxes for the petrol but I can find a few diesel boxes. Does anyone know of they will bolt straight up?

Max

[E-bmw]

I doubt they will be compatible as the speed of both cars is similar, but the engine revs are different, so the ratios will be different unless the difference is taken up by a different final drive at the diff.

[MaxRothery]

They are different, one is a 5 speed and ones a 6 speed

[TheEnd]

See if you can find the ratios.

Petrol and diesel total ratios are pretty much always different, but it can vary where the changes were made, either with the diff ratios, or in the gearbox, or both.

[MaxRothery]

As far as I can tell, the 2.7D and the 3.0 petrol have the same ratios and same final drive

[mk2 24v]

the diesel is a PSA lump though, so may have a different box entirely.
might just be the bellhousing I guess

[MaxRothery]

Maybe, I've found a manual s type that's for spares or repair so I'll probably buy that and flog the rest

[Mr2Mike]

MaxRothery said:

As far as I can tell, the 2.7D and the 3.0 petrol have the same ratios and same final drive

That seems unlikely, or at least very unusual. Diesels most always have a different final drive ratio at least, and usually closer gear ratios.

A quick google shows the following final drive ratios for the S Type, though the gearbox ratios seem to be hard to find:

2.5L Petrol
Manual 3.07:1
Automatic 3.31:1

2.7L Diesel
Manual 2.69:1
Automatic 3.07:1

3.0L Petrol
Manual 3.07:1
Automatic 3.31:1

[MaxRothery]

Mr2Mike said:

MaxRothery said:

As far as I can tell, the 2.7D and the 3.0 petrol have the same ratios and same final drive

That seems unlikely, or at least very unusual. Diesels most always have a different final drive ratio at least, and usually closer gear ratios.

A quick google shows the following final drive ratios for the S Type, though the gearbox ratios seem to be hard to find:

2.5L Petrol
Manual 3.07:1
Automatic 3.31:1

2.7L Diesel
Manual 2.69:1
Automatic 3.07:1

3.0L Petrol
Manual 3.07:1
Automatic 3.31:1

So, if the ratios are the same, could you put the diesel gearbox onto the manual as it'll have a higher torque rating?

[Mr2Mike]

MaxRothery said:

So, if the ratios are the same, could you put the diesel gearbox onto the manual as it'll have a higher torque rating?

If it physically fits (e.g. bell-housing/clutch splines etc.) it would work.