BMW 6 cylinder into 300Tdi?

[MarkWillenbrock]

I'm wondering if anyone has tried this...

I have a 300tdi with a tired engine.

It has the ZF automatic box - the same as many Range Rover P38 diesels... and many BMW 5 and 3 series diesels.

I live in Morocco and the scrap yards have a plentiful supply of BMW 6 cylinder, 2.5 td and tds engines.

I also spent much more time these days on motorways, with seven people on board and their luggage on the roof. 90 bhp from the Tdi isn't really enough.

Can it be done? I'm not worried about fabricating bits and pieces, just as long as it will fit under the bonnet!

[ComicalEngineer]

In theory, probably.

You would need to check the overall engine length, 6 cyls being longer than 4 generally. If the BMW engine is too long then that would require major surgery to the Disco. You may be able to fit one of the BMW 2.0 litre 4 cyl diesels in. Some of these give 140 bhp so would be worth it.

Also, most of the later BMWs have electronic engine management systems. A major faff to get all of the electrickery bits working. you would need the ECU and all the sensors, so:

Mass air flow meter
Exhaust gas sensor
Drive by wire throttle
Engine temp sensor
Fuel temp sensor
etc

If you can get a pre-drive by wire car then you may have a chance. I would doubt that anyone would try this in the UK because of the cost of BMW engines against cheap alternatives e.g. Nissan, Toyota.

Would be interesting to see if it can be done.

[lynalldiscovery]

There was one running around in Essex a few years back and it was always in the for sale section so maybe not that good.

Slated as slow in the P38 range rover that weighs the same as the TDI so will perform the same.

Rated at 136hp in the P38 but more in the car version.


Lynall

[TEMPL4R]

The older TDS would probably be the easiest, basic and no fancy electronics. As said though, the length is the problem. Nothing to stop you altering the front and fitting the rad to the outside though.

Chris

[bilge rat]

there is a defender or 110 with one in . its in the for sale section in lro. wonder iff hed be able to advise you ?. just a thought . alan....

[spandit]

Regarding electronically controlled engines, I fitted one in my kit car (a Chevy LS1 - wish I could put one in the Landy!!) and although there are a few more wires to link up, it's relatively straightforward. BMW make/made some great diesels - probably a bit fussier about what you pump through them, though :)

[thebiglad]

I'm wondering if anyone has tried this...

I have a 300tdi with a tired engine.

It has the ZF automatic box - the same as many Range Rover P38 diesels... and many BMW 5 and 3 series diesels.

I live in Morocco and the scrap yards have a plentiful supply of BMW 6 cylinder, 2.5 td and tds engines.

I also spent much more time these days on motorways, with seven people on board and their luggage on the roof. 90 bhp from the Tdi isn't really enough.

Can it be done? I'm not worried about fabricating bits and pieces, just as long as it will fit under the bonnet!

Hi there , I'm curious as to why you believe your 300tdi is only 90bhp, the manuals are 111 and the autos are (I believe)113.

I only mention this because IF you think you are going to get an increase in power of perhaps 45bhp, well you're not.

You might be better (certainly easier and cheaper) to refettle your existing motor, it's very possible to get 135bhp from it!!

[MarkWillenbrock]

Thanks guys; it seems I may not be too far off the mark...

It's a pre fly by wire car, so I don't have any LR electrics to fool.

I'd aim for the older, 6 cylinder 2.5tds or td BMW to avoid BMW ECU issues... Length could be an issue but there seems plenty of space around the rad to move things forward a bit.

Is the 300Tdi really 113bhp?! Mine has the head from a manual, but I wonder what gave the auto the extra? It's certainly no where near whatever the original rating was anyway. The auto puts an awful lot of rev's on this motor. My issue is really lack of power in the overtaking range, but fast motorway cruising has me backing off regularly - the Haynes manual gives 4,000rpm as the max continuous with load (4,500rpm without).

One more thing. Looking at the P38 installation, the motor seems vertical. BMW 6's seem normally to be at a slant (looking under the bonnet of my 325, and delving into memories of my previous 3,5, and 7 series). I wonder what's been done on the previous conversions - to slant, or not to slant...

[HarryD]

Will an electric fan help with the length prob? When I fitted one to my last disco, it gave me more room.

[thebiglad]

[quote=MarkWillenbrock;972583]Thanks guys; it seems I may not be too far off the mark...

Is the 300Tdi really 113bhp?! Mine has the head from a manual, but I wonder what gave the auto the extra? It's certainly no where near whatever the original rating was anyway. The auto puts an awful lot of rev's on this motor. My issue is really lack of power in the overtaking range, but fast motorway cruising has me backing off regularly - the Haynes manual gives 4,000rpm as the max continuous with load (4,500rpm without).

quote]

I seem to recall that when the TDi 300 first came out in about '94 we were invited to a an LR play day and the LR man said that the autos were tuned slightly differently to offset the losses of an auto-box.

This was a long time ago and maybe I've got this wrong but in any case there are many on this site who have tuned their TDi300 motors to achieve 135 bhp and good torque, so I ask again are you sure that you need to change the engine??

[MarkWillenbrock]

Offsetting the losses of this auto and it's undersized torque converter would be quite something! Despite the tinkering with the power output (and how did they do this? Cam? Injector pump?) and massively lowering the gearing, the car is still much slower than any manual I've driven - unless flat out on a motorway, when it will reach peak power sooner.

To be honest, if I was in the UK I would be keener to tune the original engine. Here in Morocco we don't have the army of specialists and spares availability. I'm also aware that by tuning the engine I'm reducing any inbuilt 'safety margins'. In 50 degrees of summer heat, I might need those margins!

Which takes me neatly to fans...

The same point had occurred to me. I also recall reading about someone who had simply removed the big viscous fan on his V8, letting it run on the twin electrics for the AC (which have a temp. sensor to cut in above a certain level).

I think the viscous would have to go, but I think bigger electric fans would be necessary. Lot's of big twin fan set ups in the scrappers, so that shouldn't be a problem.