Best way to run a BMW M51?

[Chicken Drumstick]

Ok, so further to my 109 thread. I've done lots of reading/research and speaking to people.

And I honestly like the idea of utilising a p38 as the base for the build. I even think I've found a way to retain the air suspension, completely independently of any p38 electronics.

I'd like to use a manual 2.5 DSE p38 as the base vehicle. But I'd like to ditch as much of the p38's electronics as possible. What is going be the best/easiest way to run the BMW engine? Can the ECU be easily separated from the rest of the p38's wiring and BECM? Do I need to source a BMW car engine ECU?

Obviously if I went for a V8 I could run Megasquirt, Disco 1 ECU or even chuck a carb on it. But the mpg of the diesel appeals, even at the cost of less horse power.

[landroversforever]

I believe there's an off the shelf loom available to run the engine on its own outside of the rest of the RR electronics. The name of the company is however escaping me at the moment! They're the ones that make the Freelanderish shaped dakar racer that looks more like a wildcat from the back.

[landroversforever]

Ah-ha! These guys I think it was: http://www.rallyraid.co.uk/shop/

[Chicken Drumstick]

 Think they might only do stuff for the M57 engine. I know these are "better" engines, but I'd just like to buy a p38 and use the engine in it if possible, the 2.5 litre M51.

[landroversforever]

Good point. Don't know how much they differ. Might be worth a call to ask? 

[geoffbeaumont]

Have a drive of one before you commit - if you're hankering for a V8 the M51 might not quite do it for you. They're smooth and much more civilised on the motorway than a Land Rover TDi, though obviously not as powerful as a V8. The real issue with them is terrible turbo lag - you may be able to live with it if you're going with a manual gearbox (IIRC that's your plan?), much more intrusive with an automatic.

And if you're buying it already in a donor P38 make sure it's a low mileage one - they're working hard lugging 2.5 tons of Range Rover around, and can be a bit thrashed (anecdotally especially the manuals, simply because they're easier to thrash).

[Chicken Drumstick]

On 9/25/2018 at 3:34 PM, landroversforever said:

Ah-ha! These guys I think it was: http://www.rallyraid.co.uk/shop/

Spoken to them, and sadly it's a no. Haven't really been able to find much else. Only a suggestion of fitting a mechanical pump to the engine. But can't find any specifics and I'm not really wanting to beat the path with R&D...

Maybe a V8 is the way to go.

[Chicken Drumstick]

3 minutes ago, geoffbeaumont said:

Have a drive of one before you commit - if you're hankering for a V8 the M51 might not quite do it for you. They're smooth and much more civilised on the motorway than a Land Rover TDi, though obviously not as powerful as a V8. The real issue with them is terrible turbo lag - you may be able to live with it if you're going with a manual gearbox (IIRC that's your plan?), much more intrusive with an automatic.

And if you're buying it already in a donor P38 make sure it's a low mileage one - they're working hard lugging 2.5 tons of Range Rover around, and can be a bit thrashed (anecdotally especially the manuals, simply because they're easier to thrash).

Ta. I have driven a manual DSE in the past, although it was some time ago. I think the appeal is really the mpg if I'm not going for the LS1 conversion, which seems to be more expensive/difficult than I'd like.

I have a 4.6 p38 now, so now how the V8's go.

[David Sparkes]

Jeremy Fearn used to run competition vehicles with BMW diesel engines, to the extent that he had his own rolling road installed.
Clearly he was was able to circumvent the security of the engine management system.

I had heard Jeremy J Fearn was no longer in business, but his website is still up. Perhaps a phone call is a worthwhile investment.
I will emphasis phone call rather than email.

Ahh, a brief look at the records in Companies House show that while Jeremy is still listed as a Director, and accounts have been deposited (next due end September 2018), a Julie Fearn resigned as secretary in Feb 2016. Assuming Julie was his wife, perhaps a marriage breakdown was the cause of any business hiccup there might have been.

Regards.

[smallfry]

Jeremy Fearn use the M57, and yes, marriage breakdown caused the demise of the business.

Remember reading an article in Practical Classics about swapping an M51 into a Reliant Scimitar. I seem to remember the guy had the engine running in the donor vehicle and cut loom wires until it stopped. He then joined the cable up and carried on cutting and joining until he had factored out the rest of the vehicle. IIRC the donor was a Vauxhall Omega, but it would still have had security devices

[Blanco]

No security devices on this one! Mechanical Pump I could be tempted to ditch some wiring myself, wonder how much all the loom and wiring weigh 

 

[cackshifter]

I think Simtek/Bodylogic also do harnesses & associated gubbins link

At a price.

[Blanco]

Realised my previous post didn't show a mechanical pump afterall, something lost in Latvian  translation perhaps. But it set me thinking, and searching.... it's a tough one to find much on but I just found this; SII with M51 so it has been done, its a carp thread but the key piece of intel contained within is that 'Diesel Bob' did the pump for it (he has his own site). Should be a deal cheaper than the Simtek route and much less of a headache. 

[miggit]

A mechanical pump is the best way of getting past the LR electronics, but possibly not the best option for power and economy. I've been thinking of sticking a Mercedes OM 606 / 605 engine into my RRC, and having done a fair amount of surfing, discovered that HoSS has used this engine in his Volvo build and has found a way around the security on the ECU to retain the electronic pump, rather than go manual.... But I haven't been able to find out how, D'OH! 

It might be worth asking him, as I imagine BMW Bosch is fairly common to Mercedes Bosch....

The other thought is if you're running a manual transmission, maybe BMW ECU / loom might be easier to deal with. 

[Blanco]

I just think mechanical suits the 109 here? Chicken D was already talking about simplifying the EAS.  The pump can still be set up to give the desired profile, suited to the usage, it just won't reprogram itself or go into limp home for that matter either. Pretty much a personal choice when it comes down to it.

[Escape]

IMHO the best way to run a M51 is in a BMW, not a Land Rover. I've had a P38 DT manual, and while it wasn't too bad, it was no where near as good as a TD5. If you want to get rid of the electronics, I'd say a 300Tdi or International 2.8 or such would be a far better choice.

[miggit]

I've got to say that the more cylinders you have the less agricultural the driving experience gets, the TD5 is a good engine, all be it BMW origine. For ease of installation and power potential, I'd look at a Mercedes OM605 or OM606, 5 and 6 pots respectively, there are adaptor kits to install them into various Land Rover models, RRC being the one that I looked into. They can be fitted with a manual injection pump, which when fitted with new elements can produce over 500 bhp.... not that I'd recommend that for a Land Rover!! but around 250 bhp is very doable, and from what little knowledge I have, doesn't involve much more than a pump change... it uses the original turbo, and they don't do anything to the bottom end either.

First thing you've got to answer is what are you trying to get ? Smooth diesel power below 150bhp then I'd look at a TD5... A little more power, not worried about the rattles then possibly tuned Tdi300 or the 2.8 International version... But if you want 200 + then Mercedes OM power is possibly worth looking at... I found a chap in Sweden, I think, who did an adaptor kit to either auto or manual RRC boxes for around £800 for the basic kit...

[landroversforever]

8 hours ago, miggit said:

I've got to say that the more cylinders you have the less agricultural the driving experience gets, the TD5 is a good engine, all be it BMW origine.

The TD5 is actually all Land Rover. BMW turned up on the scene after it was finished. It was a LR designed engine, originally going to be a family of 4, 5 and 6 cylinders but BMW came along an already had the 4 and the 6.

[Chicken Drumstick]

On 10/1/2018 at 1:35 PM, Blanco said:

I just think mechanical suits the 109 here? Chicken D was already talking about simplifying the EAS.  The pump can still be set up to give the desired profile, suited to the usage, it just won't reprogram itself or go into limp home for that matter either. Pretty much a personal choice when it comes down to it.

Thanks for all the replies.

Yes a mechanical pump seems the easiest to get it running, although I've not found much detailed info on converting them previously. The diesel appealed as it would offer sufficient grunt with a tweak and better mpg. But I'd like to ditch as much p38 wiring as possible. Which unless I'm mistaken will mean you'd need the BECM to talk to the engine ECU to disarm the immobiliser. So you'd still need a keyfob to do this. And you'd need all the sensors to say if doors are shut and the like to prevent the air suspension from being disabled.

 

Just seems a lot of faffing. And a lot of components to re-house somewhere in a 109 that you really don't want or aren't using.

 

Keeping the air suspension I would like and I've found some controllers from a US company that would work and not too pricey. You'd control the air bags per axle and they wouldn't auto raise and lower at set speeds like the factory setup, but you could have a normal, extended and entry ride height programmed and ability to control each airbag if needed.

 

A manual V8 p38 seems a better bet, but sadly hard to find.

[miggit]

14 hours ago, landroversforever said:

BMW came along an already had the 4 and the 6.

.....Pity we never got the proposed 8 pot diesel!

[Carloz]

On 10/9/2018 at 11:46 PM, miggit said:

.....Pity we never got the proposed 8 pot diesel!

You mean the Iceberg Diesel? The Rover V8 Diesel on the basis of the petrol V8!

A pitty.. it would have been THE engine for the Range Rover and Defenders in those days (the Eighties).

Always a pitty to read about those abandonded projects due lack of cash! 😕

[Escape]

Couldn't agree more! It's the same with Lotus: they worked on a V8 in de 70s, but it took 20 years before the Esprit finally got a V8 and by then they couldn't afford/find a strong enough gearbox, so had to downtune it.

[miggit]

I was actually referring to a BMW V8 diesel and V12 petrol engines that the L322 was intended to have in the design stages, but by the time of production BMW were looking to off load LR so they supplied the base model engines... at the lowest spec.... Ever wondered why the X5 diesel has the same engine and gearbox as the Range Rover but produces 50bhp more power??

The Iceberg diesel was rumored to be very noisy...