Mercedes 300 d in my Bertram

Discussion in 'Diesel Engines' started by Gary Chiles, Nov 26, 2019.

  1. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    The engine is rated to 123 HP for automotive use. That is for, at most, a few seconds of hard acceleration. Realistically, it can be run at 100 HP for continuous operation. That is 100 square inches for both engines (10 x 10). Vents in the transom are a really bad idea. Usually they are on the sides and decks with clamshells or louvered vents. However, vents in the cockpit are also common and not excessively noisy.
    Mercedes Benz W123 300 TD Turbo Technical Specs, Dimensions https://www.ultimatespecs.com/car-specs/Mercedes-Benz/2232/Mercedes-Benz-W123-300-TD-Turbo.html
     
  2. kapnD
    Joined: Jan 2003
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    Location: hawaii, usa

    kapnD Senior Member

    Interior vents can be baffled to reduce sound emission, and they don’t necessarily need to be real close to the motor.
    It’s common to take engine room air from under the gunnels where it’s dry.
     
  3. Gary Chiles
    Joined: Nov 2019
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    Location: San Diego

    Gary Chiles Junior Member

    Hey everyone! Got both engines ( mercedes 300 d turbos) in and running, they seem to run very well but will defintely need to get the props tweeked. Dog calvary was pretty dead on as far as losing a little top endspeed. staying nice and cool so far, first sea trial gave me plenty of speed even with the props a little off! Getting on plane is not a problem, almost immediately, will keep you posted as work progresses!
     
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  4. fredrosse
    Joined: Jan 2005
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    fredrosse USACE Steam

    "The engine is rated to 123 HP for automotive use. That is for, at most, a few seconds of hard acceleration."

    I had a MB 300SDL, the big car with engines available from the 120 HP turbo diesel, all the way up to much larger V-8 engines. I put close to 300,000 miles on this Diesel car, and, contrary to what Gonzo states ("a few seconds of hard acceleration" I usually had to drive it with full throttle most of the time, a clearly underpowered car. However the engine held up very well, and this engine is a jewel.
     
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  5. gonzo
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    Location: Milwaukee, WI

    gonzo Senior Member

    To compare it to a marine application, you would have to drive it uphill with a heavy load for hours on end. I think that is not likely.
     
  6. baeckmo
    Joined: Jun 2009
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    baeckmo Hydrodynamics

    Actually, all German engine manufacturers of the era, and most of the other Europeans as well, had to produce engines that were "Autobahnfest". I worked with engine development for a Swedish car company in the early seventies. The final test of a new concept was repeated full speed (and no fuzz, full speed it was, no speed limits at the time) drives from Hamburg down to the Swiss border, change crew and then full speed back. "Everybody" was there those days. These trips put some strain on the brakes as well...... So I'd say fredrosse comes close to what the 300 engine had to put up with from the beginning.
     
  7. gonzo
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    gonzo Senior Member

    Not really. The combustion chamber pressures would be lower for a car on a more less flat road. The top speed of the car is a bout 120 MPH (192KPH). You could keep those speeds in Germany, but I don't know anywhere in the USA you go that fast for a couple of hours.
     

  8. fredrosse
    Joined: Jan 2005
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    Location: Philadelphia PA

    fredrosse USACE Steam

    The 1980s Mercedes S cars, the big car, maybe could do 120 MPH with the big V8 gasoline engines, but with the 120HP Diesel, it would max-out at about 80 MPH, maybe a little faster in cool weather. As previously stated, I had to drive on the turnpike at full power most of the time. I drove from Philadelphia to Pittsburgh area once or twice a week, and I know what full throttle is, I was there.
     
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