BX petrol to diesel engine swap

[TouaregUK]

Hi every one I’m a new member although I have had several BX's over the last few years and still have four on the road, I’m looking to do an engine exchange as My BX Meteor 1.6 has lost its cam belt, its a very low mileage car is worth repairing as the car has only covered 50K and the body and interior are in fantastic condition, but I also have a 1.9 BX diesel which has the usual rust problems but very nice engine, I would like to swap them over but know that theirs more than just exchanging the engine, Fuel tank/ dash / glow plugs / ecu possible different suspension, as the diesels heaver etc, would like to know if any one else has done it and were there any problems. I need to add all mine are Autos, I have two 1.9 diesels and one 1.9 petrol and one 1.6 petrol.
cheers TouaregUK

[docchevron]

Ok. Yes it's possivle, and not all that hard to convert.
However, it's late, and I've had several ales, well, for several read, er, rather alot.
If no-one else chips in before hand I'll return to this tomorrow when I'm not, er, well, inebriated.

Oh, and welcome!

[AndersDK]

In principle you only need to swap the engine/gearbox unit.
Anything else is the same :
tank, fuel lines
suspension (except some piping must be rerouted in engine bay)
Any power steering can be retained and fitted directly to the diesel unit
brakes, hubs and driveaxles
exhaust downpipe is different but the rest of the exhaust is the same.

if your Meteor had the engine management ECU, then you just remove all the wiring coming from the RHS (cars) to the engine - and the compter under the drivers seat - together with wiring.
The complete wiring harness and computer could sell for at least £30 on Ebay.

The Wiring harness coming from the LHS (cars) near the battery is all you need for the instrument warnings, the starter motor, reverse lights switch and alternator.

You will need to swap over the glow plug timer relay and the wiring.
Any rev conter must be swapped to, as the petrol rev counter only works with 2 ignition pulses pr revolution, and the dieselunit utilises a separate TDC sensor only supplying a single pulse pr revolution.
The difference lies within the electronics on the back of the rev counter instrument.

[TouaregUK]

Ok. Yes it's possivle, and not all that hard to convert.
However, it's late, and I've had several ales, well, for several read, er, rather alot.
If no-one else chips in before hand I'll return to this tomorrow when I'm not, er, well, inebriated.

Oh, and welcome!

Cheers! appreciate any advice

[TouaregUK]

In principle you only need to swap the engine/gearbox unit.
Anything else is the same :
tank, fuel lines
suspension (except some piping must be rerouted in engine bay)
Any power steering can be retained and fitted directly to the diesel unit
brakes, hubs and driveaxles
exhaust downpipe is different but the rest of the exhaust is the same.

if your Meteor had the engine management ECU, then you just remove all the wiring coming from the RHS (cars) to the engine - and the compter under the drivers seat - together with wiring.
The complete wiring harness and computer could sell for at least £30 on Ebay.

The Wiring harness coming from the LHS (cars) near the battery is all you need for the instrument warnings, the starter motor, reverse lights switch and alternator.

You will need to swap over the glow plug timer relay and the wiring.
Any rev conter must be swapped to, as the petrol rev counter only works with 2 ignition pulses pr revolution, and the dieselunit utilises a separate TDC sensor only supplying a single pulse pr revolution.
The difference lies within the electronics on the back of the rev counter instrument.

Well that’s pretty comprehensive does that mean that you’ve already done it or
are you just technically minded. Just to confirm I don’t have to change the fuel tanks as my mate said they are different for petrol and diesel in the sense that they need to be vented differently. But then he converted old Ford transits many years ago and I suppose things have moved on since then as regards any parts on the car they will go to any one in the club who needs them as and when the cars finished.

I’m only interested in keeping as many BX’s on the road as possible although my enthusiasm is not shared by my family who can’t understand why I drive or clean and polish these old cars when I have a new car, I only have it because the family wont be seen in my old BX. no accounting for taste, The only other car that’s come close to the BX was my BMW 750i other than that I am going to rebuild this one and it will
see me out, that’s why I’m putting the diesel engine in it,

I will keep you updated as to how it goes, I wanted to put some pictures in but not sure how to do it. but will keep trying,

thanks for all the information sounds like it should be an easy job!

PS and if you need to borrow a Transporter give me a call I have a small single car
Transporter I use to carry my classic Jag around but should you need to collect an old BX just call it’s always here although at the moment its got a BX on it.

[mat_fenwick]

To put pictures into your posts, this is a handy guide. Good luck with the engine swap and I look forwards to seeing photos, maybe you could start a blog?

[AndersDK]

The tank and piping is the same.

Except you wont need any electric fuel pump for the diesel.
There are no differenes in the venting of the tank - why wuld that be necessary ?
The diesel tank is not pressurised if thats what your mate thinks.

Of course you will have several minor differences here and there - according to the completely different fuelling principle.
But then again you have a complete car as donor and can always go get the odd bits you need.

Good luck and happy BX-ing

[Way2go]

It's probably worth checking with your insurance company what the cost change implications are before embarking, as others have had loadings for the car being no longer standard irrespective of there having been an equivalent model in the range.
It's difficult to understand why they would charge more than had it been an original car of the diesel type but that's insurance companies for you!

[Mike E (uk)]

You may have to change the autobox too because the ratios on a petrol car will be all wrong for a oil burner.

Why do you want to convert it to a diesel?

It would be far easier to fix up the engine.

Very worthwhile as it is low mileage, and only an 8v makes it simple.
you may have only 2 bent valves.
Have you fitted another belt and done a compression test?

You only have one repair to do, rather than a whole bunch of stuff that will take ages. While you are at it, fit a new set of valve guide oil seals and you will be sorted for years to come.

If you want to run it cheaply, you could convert it from petrol to LPG.

It will be cheaper to run than a diesel, with better performance, and no problem getting insurance.

[TouaregUK]

You may have to change the autobox too because the ratios on a petrol car will be all wrong for a oil burner.

Why do you want to convert it to a diesel?

It would be far easier to fix up the engine.

Very worthwhile as it is low mileage, and only an 8v makes it simple.
you may have only 2 bent valves.
Have you fitted another belt and done a compression test?

You only have one repair to do, rather than a whole bunch of stuff that will take ages. While you are at it, fit a new set of valve guide oil seals and you will be sorted for years to come.

If you want to run it cheaply, you could convert it from petrol to LPG.

It will be cheaper to run than a diesel, with better performance, and no problem getting insurance.

Hi I’m just getting my head round how one replies think i might have cracked it now. so in answer to your suggestions’ I have a complete car and would swap both engine and gearbox as one lump as they run really well, The Meteor was running fine but after the 1.9 diesel seemed slow and had no torque also the gear changes were not as smooth, it always seemed to not be in the right gear, I have had this before with autos being under powered never on a larger or more Torqueier engine. also I think in the future petrol and both diesel will be more expensive and we might be looking at old vegetable oil etc, I also seemed to get around 45 to the gallon. on the diesel,
I no that as the price of diesel creeps above that of petrol that advantage might be less. but one can always get hold of used cooking oil etc.
If any one wants a low milage 1.6 auto engine and box please let me know we are in North London.

[Mike E (uk)]

Veggie oil is a good plan, but I think it is getting more popular now, so may become harder to source.

I suspect that a 1.6 auto petrol (especially with a carb) is quite thirsty.

Mike

[Vanny]

*Fuel lines ARE different. Bit of mix and match should sort that, the metal pipes are near enough to being the same.
*You might have problems if the pump is gear box mounted instead of gear box mounted.
*Check there are no differences between drive shaft thicknesses.
*You may have problems (additional) with plumbing if the recipient car has ABS.
*Fuel tanks are all identical, except for the filler nossle, on some cars the petrol filler is considerably smaller and wont allow a diesel nossle. Indeed citroen list two different part numbers for petrol and diesel filler necks.
*Use the diesel battery to save cooking the battery/alternator
*Consider doing the cambelt and water pump while the diesel engine is hovering.
*Buy some welding cable and correct solderable crimps and replace the earth from battery to gearbox (makes a hell of a difference to sarting and glow plug efficiency)
* The exhaust should be different, though subtley. Suggest you remove the entire 1.6 exhaust and replace with a complete 1.9 exhaust if in fine fettle.
*you can take the diesel engine 'sensor' loom and plug it into the petrol engine 'sensor' loom, might need to move a few pins around (they all unclip) but the wiring is fundamentally the same.
*Read whats ben said about the rev counter. If you do have a diesel counter to put in then its much quicker to simply add extra wires than try to rewire the existing. Only takes three wires!
*Consider fitting the Xantia style glow plug relay, undamentally the same wiring, but includes a better run on timer for the plug increasing plug life, and helping cold strating A LOT
* Most of the cooling system might need to be moved over (hard to tell without comparing first hand)

ABSOLUTLEY check with the insurance company first. I've been had twice with my petrol to diesel and NA to turbo conversions and its a costly mistake! I used to drive a engine modified BX16v (with a TD engine) and paid DOUBLE what i now pay for just the valver engine (now i pay double for fuel instead.

DVLA has proper tightened up on conversions and WILL require a certificate from a reputable (VOSA) garage to prove that the conversion has been carried out (thanks to tax dodgers). I got round this by having the car MOT'd the engin type changed on the VOSA system then sending the MOT to the DVLA along with a LOT of other paper work (purchase receipts for both cars, SORN and scrap certificate for the donor showing engine number that matched that going into the recipient etc etc)

More fool me but i've been here and done this too many times now. Not once has it actually been worth while for me.

[TouaregUK]

You may have to change the autobox too because the ratios on a petrol car will be all wrong for a oil burner.

Why do you want to convert it to a diesel?

It would be far easier to fix up the engine.

Very worthwhile as it is low mileage, and only an 8v makes it simple.
you may have only 2 bent valves.
Have you fitted another belt and done a compression test?

You only have one repair to do, rather than a whole bunch of stuff that will take ages. While you are at it, fit a new set of valve guide oil seals and you will be sorted for years to come.

If you want to run it cheaply, you could convert it from petrol to LPG.

It will be cheaper to run than a diesel, with better performance, and no problem getting insurance.

Hi I’m just getting my head round how one replies think i might have cracked it now. so in answer to your suggestions’ I have a complete car and would swap both engine and gearbox as one lump as they run really well, The Meteor was running fine but after the 1.9 diesel seemed slow and had no torque also the gear changes were not as smooth, it always seemed to not be in the right gear, I have had this before with autos being under powered never on a larger or more Torqueier engine. also I think in the future petrol and both diesel will be more expensive and we might be looking at old vegetable oil etc, I also seemed to get around 45 to the gallon. on the diesel,
I no that as the price of diesel creeps above that of petrol that advantage might be less. but one can always get hold of used cooking oil etc.
If any one wants a low milage 1.6 auto engine and box please let me know we are in North London.

Hi Mike, fantastic information I will now reconsider the whole project will let every one know when I decide what to do I’m of to Eastbourne now to work on my old 1965 S Type Jag its in the paint shop I’m going to rub it down and hopefully paint it by the end of the week, will consider all the options over the week end thanks very much I value your advise, mine is based on experience of old classics, don’t rebuild old classic cars unless you’ve won the lottery better buy one that’s already done for half the money. cheers