Engine Conversion - BMW M57 into a 90

[LiamC]

I’m about to start an engine conversion and I thought it might be interesting to some people if I share the progress of my project. This is definitely going to be a slow project as I don’t have time to work on this regularly.

When I purchased my 1988 90 I had always intended to replace the 2.5N/A engine at some point, partly because it would be nice to have more power but mainly because I fancy the challenge. I was originally looking to use a Mercedes OM606 but have now decided to go with the BMW M57 as it’s a bit more refined and economical. This engine is a common rail inline six cylinder diesel with an excellent reputation. I have decided to use the older version of this engine which produces 184BHP in standard form.

My boss very kindly let me borrow the work lorry to go and collect my doner vehicle which is a BMW E39 530d touring with only 78k miles on the clock. This car had suffered water ingress where it had been stood for some considerable time, which in turn has caused considerable corrosion to the many electrical connectors that are under the driver’s carpet. As a result nothing electrical is working properly apart from the engine systems. The car won’t even drive as the auto box is stuck in 3rd. I paid £700 for the car which might be a bit high but the seller wouldn’t budge and it is worth it to me just for the low mileage engine.

I have started to remove a few bits and bobs in the evenings, in preparation to lift the engine out when I get a free weekend.

 

[Blanco]

Definitely interesting, .... are you going with auto or manual box?

[LiamC]

I'm still considering my options gearbox wise, but the current plan is to source a GS6-53DZ 6 speed ZF manual from an E46. It's a very strong box and the E46 version will bolt straight up to my 184 M57. The tricky bit is mating it to the transfer box, there are close couple adaptors available.........they are expensive but this would be a neat solution. A cheaper option would be to use an R380 with a P38 bell housing, but this is right on the limit of what the R380 can handle and I think it would spoil the enjoyment of driving it if I'm constantly worrying about over stressing the gearbox.

[FridgeFreezer]

2 minutes ago, LiamC said:

I'm still considering my options gearbox wise, but the current plan is to source a GS6-53DZ 6 speed ZF manual from an E46. It's a very strong box and the E46 version will bolt straight up to my 184 M57. The tricky bit is mating it to the transfer box, there are close couple adaptors available.........they are expensive but this would be a neat solution. A cheaper option would be to use an R380 with a P38 bell housing, but this is right on the limit of what the R380 can handle and I think it would spoil the enjoyment of driving it if I'm constantly worrying about over stressing the gearbox.

I have a theory that it's big 4-pot diesels that kill LR gearboxes as they are putting out 4 big thwacks per rev, while an I6 or V8 is dividing its torque over more "beats" per turn and smoothing the shocks out. Also if it's got a DMF that might help as people rarely have those in clunky old diesel conversions - guessing there's a reason modern manufacturers fit them to everything!

Whether your lump falls into the "OK with an R380" category is hard to say, LR hung the R380 behind the 4.0 V8 and the TD5 but not the 4.6, I run two 4.6+R380 combos and (touch wood) no issues yet.

[Chicken Drumstick]

Interesting project. Have read about a few of these and do find them quite interesting.

For me though, they always seem like a huge amount of work and a lot of money to get running.

I know the M57 should be able to make good power and good mpg. But part of me says swapping in a Rover V8 would be a lot easier and cheaper. And likely be a nicer engine overall, just not as frugal (which only really matters if you are doing high mileage or very long distance overlanding).

The Td5 is also a pretty straight forward swap, and while it won't match the M57 for outright power when tuned. They are pretty easy to get to around 180hp from.

I think if I was going for a "big" engine swap, I'd be looking at a LS1 or maybe a Jaguar V8. But the issue of the gearbox always seems to the biggest problem. As I'd personally much rather have a manual.

[Peaklander]

Oh an 01367 tele. code. that brings back memories!

I'll read your progress with interest. It's one of those 'possible changes' on my list.

I follow the M57 group on fb and it's very busy. There's a lot of people with plenty of experience and options there.

Good luck!

[landroversforever]

50 minutes ago, Peaklander said:

Oh an 01367 tele. code. that brings back memories!

Not far from me!

[Peaklander]

🤣 not far at all. 

[LiamC]

4 hours ago, FridgeFreezer said:

I have a theory that it's big 4-pot diesels that kill LR gearboxes as they are putting out 4 big thwacks per rev, while an I6 or V8 is dividing its torque over more "beats" per turn and smoothing the shocks out. Also if it's got a DMF that might help as people rarely have those in clunky old diesel conversions - guessing there's a reason modern manufacturers fit them to everything!

Interesting theory, sounds plausible. Most folks that do this conversion seem to favor a single mass flywheel, presumably for reliability, but a dual mass is an option for either gearbox set up. 

 

4 hours ago, Chicken Drumstick said:

For me though, they always seem like a huge amount of work and a lot of money to get running.

Yeah you are right, it is going to be a lot of work, but I'm in no rush and this helps to spread the cost over time as I go. Hopefully it'll be fun too and I'll learn a few things along the way.

 

3 hours ago, landroversforever said:

Not far from me!

Indeed Ross. As I think you may already know, I work for your old neighbor Neil Kinch.

How's your project going? You've gone for an OM606 I believe? I'd love to come and have a look some time if you would be up for showing round?

 

[Chicken Drumstick]

I look forward to your updates

[landroversforever]

1 hour ago, LiamC said:

Indeed Ross. As I think you may already know, I work for your old neighbor Neil Kinch.

How's your project going? You've gone for an OM606 I believe? I'd love to come and have a look some time if you would be up for showing round?

 

Yeah! Useful being able to borrow the truck! 

Slowly.... it’s not progressed in a year as I’ve been waiting on some machining. Of course, drop me a PM and we can find a time! 

[Daan]

Interesting. I would stay with landrover parts for the gearbox, as it makes the job  about 10X more straightforward.

If you think the gearbox is over stressed, I would not go for the single mass flywheel, as it will make life of the gearbox harder.

Does the P38 diesel not have an auto option?

Daan

[Carloz]

On 10/10/2019 at 4:32 PM, FridgeFreezer said:

I have a theory that it's big 4-pot diesels that kill LR gearboxes as they are putting out 4 big thwacks per rev, while an I6 or V8 is dividing its torque over more "beats" per turn and smoothing the shocks out. Also if it's got a DMF that might help as people rarely have those in clunky old diesel conversions - guessing there's a reason modern manufacturers fit them to everything!

Whether your lump falls into the "OK with an R380" category is hard to say, LR hung the R380 behind the 4.0 V8 and the TD5 but not the 4.6, I run two 4.6+R380 combos and (touch wood) no issues yet.

Well the 184hp  M57 is 390 or 410Nm so it is over the edge (like the 4.6)... So, yes, it will live as long it is not used over the 380Nm all the time.

I was running a 4.2 LSE V8 (in fact a 4.3 hence 4276cc) with a LT77 which went all right till the engine cracked.. 😕

For the torque spikes there are springs in the clutch plate. I agree they are harder needed with big four pots for the reason ypou mentioned but in the end the 380Nm for the R380 was not set for nothing...

[Carloz]

On 10/11/2019 at 10:11 PM, Daan said:

Interesting. I would stay with landrover parts for the gearbox, as it makes the job  about 10X more straightforward.

If you think the gearbox is over stressed, I would not go for the single mass flywheel, as it will make life of the gearbox harder.

Does the P38 diesel not have an auto option?

Daan

Yes, P38 has also Autobox. I think most of them had, with the manual more as an exception. With the BMW M51 2.5 6pot. But it has a quite smallish torque converter (as you can read @ Ashcroft).

But you can use the R380 with care or get it upgraded. In upgraded form it should be reliable as long you don't upgrade the M57 which is not really needed I guess...

Edited October 13, 2019 by Carloz

[JohnnoK]

Something like this?

https://www.onlinegearboxparts.com/product/bmw-m57-to-300tdi-r380-adaptor-kit/

From here..

https://www.onlinegearboxparts.com/product-category/adaptor-kits/

[RedLineMike]

On 10/11/2019 at 9:11 PM, Daan said:

Interesting. I would stay with landrover parts for the gearbox, as it makes the job  about 10X more straightforward.

Daan

personally i wouldnt go down that route as the box then becomes a collection of items put together to work rather than using a complete assembly either the BMW 6 speed or the R380 with an adapter plate

[LiamC]

Well if I had a suffix K or L R380 lying around then I would probably use that. Unfortunately my 90 currently has an LT77 which simply won't do. I do have a good R380 in the back of the garage but it is a suffix J which is not as strong as the later TD5 R380s. Yes you can buy an uprated R380 from Ashcroft which would be great but they're about £1200, if I'm going to spend that kind of money I would rather buy a transfer box adaptor and use a BMW 6 speed. Would be nice to have six gears too.

[Carloz]

On 10/15/2019 at 8:46 AM, RedLineMike said:

personally i wouldnt go down that route as the box then becomes a collection of items put together to work rather than using a complete assembly either the BMW 6 speed or the R380 with an adapter plate

So far I know with the R380 it is possible to use the M57 without the use of any adapterplates: P38 M51 Gearbox with LT230 behind it. 👀

But in that way you keep the piece of porcelain between Engine and transfercase....

[RedLineMike]

the r380 with the m51 bellhousing & questionable clutch mechanism is "reasonable" at best & is an ideal option if a slipping clutch on a mild tune is your thing

[LiamC]

You can't actually use a complete R380 from a P38 as the rear end is different because the P38 didn't have the LT230 transfer box. The common thing to do without using an adaptor plate is to use a defender or discovery R380 and then source the bell housing from the P38. Indeed the P38 clutch/DMF setup isn't good enough for the M57 but clutchfix do a very good clutch and SMF to suit. As I have mentioned though, I would want to use a late suffix R380 which I do not have and to be honest I'm quite keen to try and get the six speed in there. Ashcroft now offer a 1.1:1 ratio gearset for the LT230 which I think would be perfect with the lower ratios in the BMW box.

[Chicken Drumstick]

What vehicles were the BMW 6 speed boxes used in?

[LiamC]

The 6 speed manual is a gs6-53dz which is used it all sorts but needs the correct bell housing for my engine so I'm looking for one from e46 330d. 

[LiamC]

I had a free day on Saturday so thought it would be a good opportunity to get the engine out of the doner car. It all went quite smoothly really. I'm going to remove a few more parts from the car and put them up on eBay to try and recover a little bit of the cost, then I'll have to get the BMW off to the breakers yard so I can free up some space at home.

[LiamC]

A small update. The doner car has gone now, in the end I recovered £400 from the sale of a few parts from the BMW, so the engine has effectively cost me £300 which I'm quite pleased about.

I bodged together a temporary stand alone wiring loom to see if I could get the immobiliser working. With a bit of time going through various pinouts I got the starter to crank and I can connect to the ECU with the INPA software so its looking good.

I also used the time I had during the wet weather to refurbish a 300tdi discovery rear axle which I picked up back in the summer. When we eventually had a dry weekend I managed to get it fitted to the 90. I always planned to fit disc brakes at some point and thought it better to get them sorted before installing the new engine.

I have finally found a sensibly priced BMW 6 speed manual gearbox with the correct bell housing for my engine, I'm going to have a look at it on Saturday so hopefully I'll be bringing that home.

[Peaklander]

Very nice work and that's a nice little bit of money back. Where is the adapter to the LT230 going to come from? I think you said there are a couple of options.