Marinising BMW 3.0 Turbo diesel

Rokraider · 10 April 2011, 10:47

I am in the process of fitting a BMW 3.0 turbo diesel into my RIB. This is the same engine as used in the 2003 Range Rover (latest shape) and BMW530D. I totally stripped and rebuilt it (didn't really need anything doing) and have modified the ECU to work without the usual car stuff around it, (alarm, immobilser etc) have fitted a larger Turbo and injector nozzles and have remapped the ECU to run around 270 BHP @ 4000 RPM. I would be interested to hear any suggestions of potential problems I could be facing, using it in a marine environment. The RIB is glassfibre, it will be connected by a double CV jointed propshaft to a Castoldi 238 that has 10 or so anodes. I originally was going to cool the engine with a heat exchanger and salt water doing the cooling, but it will spend most of its time in and around Chichester Harbour where there is a fair amount of seaweed to get sucked in. I am now considering mounting an aircooled radiator above the jet on the outside of the transom with a couple of ducted electric fans doing the cooling. This should avoid the problems of seaweed blocking the intake. Apart from the obvious potential issues sealing all the electrical connections, are there any other issues I should be considering?

I have been trying without luck to find out about whether electrolysis is going to be an issue. Most of the articles I have read seem to mostly concern mooring on a jetty using a powerline for electrics. The RIB will live on a trailer when not in use and will be thoroughly washed off after each trip.

Any advice would be welcome.

Mollers · 10 April 2011, 10:54

Brilliant engine IMV.

Vector Mirage (ribnet member) is the man to talk to. He's a smart motor engineer who has fitted and heavily modified a Ford Cozzy lump in a rib.

BogMonster · 10 April 2011, 11:02

I seem to remember reading an article about BMW engines being used in a race boat - it was in RIB Magazine maybe 2-3 years ago. There was something about having to cross-brace the blocks otherwise they would let go where the engine mounts attach. May only be relevant to race boats and sorry I can't recall the details but I think it was the same engine - may be worth looking into anyway?

Rokraider · 10 April 2011, 11:26

Thanks for your comments. I believe the race boat was using a pair of the later spec engine that has an aluminium block. I spoke to Paul Lemmer (spl?) who was on the RIB doing the Round Britain. Apparently they were a lot more economical than anticipated but, as I understand it, the blocks cracked due to the constant crashing up and down. (incidently, Paul built my BWM Sea Explore RIB).
I am not building this boat for high speed, more as a useful tug for towing groups of dinghies in, when the wind drops or the conditions are difficult to get them back into Chi harbour.
We are hosting the Flying 15 worlds in July and they are heavy boats to tow, the 4.7 club RIBS with 50HP outboards can just about do one at a time in reasonable conditions. If the wind drops we will be facing getting 150 boats in from the Bay.

Searider · 10 April 2011, 12:34

Exhaust manifold / turbocharger / exhaust cooling? It's going to get hot in that engine box!

Radiator will need to be quite big and have good airflow - but a radiator specialist should be able to advise what you need.

If you've only got freshwater / antifreeze mix going round the engine I can't see corrosion being a problem. The engine is not getting near the sea.

One of the 260hp Yanmar engines is based on that engine.

Joshv6 · 10 April 2011, 18:05

Yer the 6by.
If your going down the rad root why not try keel cooling.

Cheers Josh

jwalker · 10 April 2011, 19:12

In the usual marine setup, the heat exchanger cooling sea water is dumped into the exhaust, primarily for cooling the exhaust to manageable temperatures but thereby also silencing the exhaust. Your turbo charger will give some silencing. You are going to seriously consider the lagging of your exhaust system to prevent a fire. My inboard installation, unlike a car engine, does not use earth connected to the engine block this is to help prevent corrosion because the block will connect to the sea water via the drive. The upshot of this if you wish to go that route, is to have an alternator and starter motor which has an isolated earth.
Another thought is the long term corrosion resistance of your radiator since the large airflow you will require is pretty much bound to contain salt water moisture. I suppose a car engine does too during the winter time so maybe it's not such a great concern.

Rokraider · 10 April 2011, 19:50

My local radiator company build some copper and brass cored radiators for use on marine based equipment, such as cranes etc. They make their own cores from scratch and reckon they can build me a core that should last for a fair while in a salty environment.
I have found a company that makes a purpose built muff to go around the turbo and lags the manifold and exhaust. I am planning to have a very short exhaust run straight off the turbo and out through the transom. I may put a small stainless steel cherry bomb in the system to take the edge off the exhaust note. One area of concern is keeping sea water ingress out of the exhaust when the engine is switched off. I have a vacuum pump on the engine that could operate a diaphram that holds a flap open when the running and a reasonably strong spring could hold a flap shut when stationary.

Have been considering some sort of keel cooler system, but I think the aircooled radiator route is the simplest at this point.
I design and build 4x4's for a living. We often put the radiator in the rear to stop it getting blocked with mud when in the serious poo, where it gets no direct airflow. I regularly cool 250 -300 BHP using this method and don't see why I can't apply it to the RIB. If it doesn't work I will have to consider other routes.

Haven't got my head round the reason for giving the alternator and starter its own earth. I haven't found an article that explains the ins and outs of it all.
As I have to build a flywheel from scratch, I have been considering fitting an insulator/ shock absorber that would be incorporated between the flywheel and propshaft. This should prevent an electrical circuit between the Jet and engine.

two stroke mick · 11 April 2011, 09:21

I have a BMW 2.2 petrol. This engine is an ali block and head. I dont know about the 3.0lt dsl engines. but if it is an ali block be very careful of overheating. If the engine is ali block and head and it gets over headed it is for the bin.

TSM

Rokraider · 11 April 2011, 15:54

Quote:

Originally Posted by two stroke mick

I have a BMW 2.2 petrol. This engine is an ali block and head. I dont know about the 3.0lt dsl engines. but if it is an ali block be very careful of overheating. If the engine is ali block and head and it gets over headed it is for the bin.

TSM

The 2003 model that I am using (M57) is a steel block, so hopefully will be a bit stronger than the aluminium type. It would have been nice to have the lighter ali block for the weight saving, but they are at least twice the price to buy, being a newer model.

clinton2006 · 03 January 2012, 22:45

Hi there, at the moment i am seriously considering fitting a 2002 3,0d bmw engine in my 23ft relcraft and would love to know how you got on with your project, i am especially interested
in the work you have done on your ecu. I would really appreciate any input you may have.
Cheers Clint

Leapy · 04 January 2012, 07:04

.....

Rokraider · 04 January 2012, 07:37

Haven't finished the project yet, it is still ongoing. I have had the ecu modified to a programable chip, I have also modified the unit that interfaces with the car, effectively tricking the ECU into believing that it is still attached to a car with regards to the immobiliser system etc. I am running bigger injector nozzles and turbo as am aiming for 275 BHP. The next step is to run the engine on a dyno to check everything works and then get it in the boat. I am still working on some hull modifications that I need to finish before fitting the engine.
Work is interrupted whilst I give the Porter a makeover and annual service etc.

diverbert · 04 January 2012, 08:54

don't you need a bigger oil carter? Or am i thinking wrong?

Rokraider · 08 January 2012, 11:46

I am fitting a large oil cooler and Intercooler for the turbo. The Range Rover sump I am using has a good size capacity (8 litres +-?).

Cookee · 10 January 2012, 08:07

If it's the current 3 litre BMW motor then Yanmar already marinise it?

p h holder · 10 January 2012, 15:17

the earth is not a real earth but a path back to the negative of the battery.in the old days the earth was the posative battery terminal and the chassiis was the return path saving on wiring.therefor the return wire will have to be as large as the possitve and the sum of the total current

Erin · 10 January 2012, 15:54

I think you'll find that a lot of the newer diesels can have a relay in the circuit that isolates the block/chassis from the circuit once the engine is started. This reduces the risk of stray currents and corrosion, particularly in steel boats. It also means there is no galvanic circuit involving the engine or anything attached to it when the boat is idle.

Rokraider · 10 January 2012, 16:41

Quote:

Originally Posted by Cookee

If it's the current 3 litre BMW motor then Yanmar already marinise it?

At a price!! So far mines has cost around £3000

captnjack · 10 January 2012, 17:04

I have never heard of an air cooled marine engine of that size, hp, and heat production. Not having any cooling water I'm guessing you'll have dry exhaust too? That would be a bit odd on a trailered boat around here.