Petrol to diesel swap??

IOWBX · Post by **IOWBX** » Sun Mar 06, 2011 3:30 pm

Does anyone know the intimacies of the 1900cc petrol and diesel blocks. I am wondering if it is feasible to 'easily' swap a 1.9 petrol to 1.9d and in particular if the bellhousing fits on the gearbox etc..

rmattila · Post by **rmattila** » Sun Mar 06, 2011 5:09 pm

I can start, even though I know next to nothing about BX petrol engines.. I've done a few petrol-to diesel changes on my Vans, but have always changed the entire package (engine + gearbox).

According to Haynes, the possible 1,9 l petrol engine variants are

159 A (XU9S): BX 19
D2A (XU92C): BX 19 TRS (from July 1986)
D2E/F (XU92C+): BX 19 TRS/TZS (from 1990)
D6A/D (XU9J2): BX 19 GTi
DKZ (XU9JAZ): BX 19 TZi with catalysator
D6C (XU9J4): BX 19 GTi 16 valve

And the diesel engines are of course all XUD 7, XUD 7TE, XUD 9 or XUD9A.

Since all these engines appear to be of the XU type, my guess would be that they share the same gearbox mounting.

But as I said, I'm no expert on the petrol engines, so I might well be wrong on this.

ken newbold · Post by **ken newbold** » Sun Mar 06, 2011 5:33 pm

I'm fairly sure they will match up, problem is the gear ratio's are going to be different between petrol and diesel, so better to change to whole package

rmattila · Post by **rmattila** » Sun Mar 06, 2011 6:02 pm

Google found that list on different ratios used in BE3 boxes. It doesn't seem to include BX models, however.

The ratios for "405 SRI / 1.6 GTI C/R" seem to be identical to the BL62 type BE1 box used in BX 19D/RD up until 1989.

My oldest Van (the one with XUD7) has a gearbox with unsuitable ratios, and it's really annoying to drive: with 4th gear it hardly goes beyond 85 km/h (especially with a trailer), and the fifth gear only begins to pull from 90 km/h on. The box came together with the engine, and I did not check the ratios before fitting the package in the Van. Next time I'll certainly be more careful with that.

IOWBX · Post by **IOWBX** » Sun Mar 06, 2011 6:08 pm

thanks for the info - changing the 'box isn't an option nor the final drive - 'tis a 4x4 diesel I would like to create...... They were available in France so may be able to pick up one there or possibly an engine gearbx package but in the meantime I was considering the feasibility of a swap but it seems the ratios would be the main issue (and also the fragility of the transfer shaft on the 4x4)

rmattila · Post by **rmattila** » Sun Mar 06, 2011 6:21 pm

Would this help?

smiffy1071 · Post by **smiffy1071** » Mon Mar 07, 2011 4:44 am

Yes, it's easy to swap from petrol to diesel, or back to front. However, are you prepared to pay the HEAVILY inflated insurance premiums, bearing in mind that the car will now be a "modified" vehicle?

It would be unlawful not to declare it.

Kevin B · Post by **Kevin B** » Mon Mar 07, 2011 10:35 am

thanks for the info - changing the 'box isn't an option nor the final drive - 'tis a 4x4 diesel I would like to create...... They were available in France so may be able to pick up one there or possibly an engine gearbx package but in the meantime I was considering the feasibility of a swap but it seems the ratios would be the main issue (and also the fragility of the transfer shaft on the 4x4)

Thats not strictly correct, because although the 4x4 BX gearbox housing is unique to the BX4x4. With the exception of the component that takes the place of the differential housing, all of the internal components are interchangable (including the crownwheel).

Which means you can also change the final drive ratios, but increasing the overall final ratios, would also increase the torque transmitted through the gearbox, and as you have identified the fragile nature of the coupling between the g/box and transfer box would be the life limiting factor of such a modification.

I believe that some members of this forum are working, or were working on a 'final solution' for this well known weakness.

MULLEY · Post by **MULLEY** » Mon Mar 07, 2011 1:06 pm

I think our Scandinavian friends have already sorted out the fragility factor mentioned.

Kevin B · Post by **Kevin B** » Mon Mar 07, 2011 2:21 pm

MULLEY wrote:I think our Scandinavian friends have already sorted out the fragility factor mentioned.

Only by using the gearbox and transfer box from a Peugeot Mi16 4x4.

I believe that Brian King was / is investigating the manufacture of parts that can be used in the BX4x4 gearbox.

MULLEY · Post by **MULLEY** » Mon Mar 07, 2011 8:26 pm

Nope, they've sorted out the real issue, i'm sure i posted up the details of the chap that pm'd me?

Kevin B · Post by **Kevin B** » Tue Mar 08, 2011 8:46 am

Nope, they've sorted out the real issue, i'm sure i posted up the details of the chap that pm'd me?

In which case I humbly stand corrected, could you possibly repost that info on this thread, as it would be of interest to me, being as I also own a couple of 4x4 Bx's.

Thanks in anticipation Mulley.