BMW M21 Diesel Marine Engine Conversion?

Discussion in 'DIY Marinizing' started by Northwester, Oct 27, 2010.

  1. Northwester
    Joined: Sep 2007
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    Northwester Junior Member

    I'm wondering if anyone makes a marinizing kit for the BMW M21 524TD engine.

    M21 2.4l inline six diesel engine based on m20 gasoline engine.

    The turbocharged version made 114 bhp at 4800 r.p.m. The piston domes are oil cooled and the crankshaft is forged. Seems well enough engineered for marine use.
     
  2. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    I'd say no..as it is 26 years old...I was an auto broker and have seen but a few of these.
    I guess you know that was in the 524 td and some Lincolns...that 114 hp is peak and for very occasional use.

    I'm guessing it'd be best to run at 40-50 hp to last,which you want it to do as they didn't sell many of them and parts are pricey and rare...and specialty tools (only at BMW dealer) required for any significant work.

    Many of them had the timing belt break and grenade the engine....or the transmissions would blow and they would be scrapped

    You obviously have the engine and want to use it for cheap,but if you're looking for cheap car based diesel try a VW TDI or Mercedes 300 turbo.
     
  3. Northwester
    Joined: Sep 2007
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    Northwester Junior Member

    I appreciate that 114 bhp @ 4800 would be for peak use only and that a continuous output of 50 bhp @ 3000 or so would better insure (but not guarantee) longevity. Frequent changes of the camshaft timing belt would have to be part of the regular maintenance program. I imagine the engine is quite commonly in europe.

    My 25' planing hull vessel currently has 2 x 165 hp inline 6 gas engines that I would like to replace with 2 x inline 6 diesel engines. I'm guessing that 100 - 125 total hp would be needed to maintain the 5000 lb. vessel on plane at 15- 20 knots.

    I haven't bought any engines yet but I'm searching for suitable lower weight candidates to marinize. I would much prefer inline 6 configuration because they tend to idle much smoother than their 4 cylinder cousins and not shake everything on board to pieces.

    I've also considered a smaller 6 cylinder industrial diesel used by Hino in trucks and forklifts as a potential candidate. I've also considered some Toyota engines as well.

    Besides VW and Mercedes, are there other engines that would be worth considering where a water jacketed marine manifold can be readily obtained?
     
  4. Carteret
    Joined: Jan 2004
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    Location: Eastern NC

    Carteret Senior Member

    The 4 cylinder Yanmar 4LHA would be a good candidate. And If you could find a couple, the DDA aluminum 353TI at 200 hp is very tough customer.
     

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  5. fcfc
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    fcfc Senior Member

  6. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    FC-those aren't here..

    Hey NW i just had a thought you may want to look into.

    I used to be heavily in the car import/export business..and was one of the first to bring in the Japanese Domestic Market cars.
    Then everyone started doing it and flooded the market and made it a PITA.FYI the statute is 15 years,in the US it's 25 years...so the cars from 1995 can come in but I think newer engines are allowed.

    There are many businesses bringing in JDM engines for replacement in the same mod3ls here...maybe you can get a couple good low km JDM Toyota/ Hino light truck engines (used by Yanmar).I'm sure its the same ones used in the Landcruisers.Perhaps a little research is in order..maybe contact Japanoid and ask, or on the RIV website.

    I'm thinking maybe $2500 an engine...if you google you can even find JDM companies who will ship you the engines,instead of going through a broker and getting charged $1000 (like I used to do).

    Paperwork is basic,research is needed on the regs.
     
  7. Northwester
    Joined: Sep 2007
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    Northwester Junior Member

    Using a JDM truck engine. That's a great idea and the kind of innovation I'm looking for. Nearly all 'consumer' class marine engines begin life as an auto or light truck engine. If I can find a match between a Yanmar marine engine and it's corresponding truck engine, the Yanmar water jacketed marine manifold should bolt right on to the cylinder head.

    The other missing bits such as oil coolers, heat exchangers and raw water pumps are easily sourced elsewhere.

    I started down this road a while ago using a Toyota 2H 4.0l diesel as the base engine. The 2H has some features which lend itself well to a marine conversion such as:

    -smooth running inline 6 cylinder engine;
    -cast iron block and cylinder head;
    -gear driven camshaft;
    -simple OHV valve train;
    -mechanical governor.

    Is there a Yanmar expert in the crowd that can help out? Did Yanmar or other Japanese marinizing company ever use the Toyota 2H as a base for a marine engine?
     

  8. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    Isuzu makes good marine engines and marine gensets.You may find the corresponding engine in a JDM Trooper/SUV or medium truck and maybe you can get exhausts from Klassen or the dealer in Seattle ...maybe will fit.
    The GMC cabover cube vans running all over are rebadged Isuzus...

    Mitsubishi? Lots of JDM Pajeros and Nissan JDM diesel Safaris around.

    If you can lay your hands on old Nissan sd33,bullet proof and fairly common in marine apps...Tollycrafts,Bayliners.

    Need to goog and email..if I think up anything else I'll let u know.
     
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