Here's a great design idea for an inboard engine.

Discussion in 'Inboards' started by thudpucker, Jul 8, 2009.

  1. thudpucker
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    thudpucker Senior Member

    this is a 48 Tucker flat six. Supposedly a Helicopter engine. Torque is great. 360 Ft Lbs at 2500 Rpm.
    But look at the organization. The Starter and Generator is on Top the engine. The Carb is as well.
    The exhause goes out the bottom.
    In another life time, I was going to have a boat with opposed Six's. I was going to make a water cooled shield between the bottom of the engine and the hull and just run the exhaust dry to the back side of the Riser. Two photos.
    48 Tucker engine.jpg 48 Tucker engine two.jpg

    Just think how much lower the shiouette would be with Multi-port EFI. Dont those look like individual cylinder heads?
    Much like the Corvair air cooled engine.
    2 people like this.
  2. masalai
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    masalai masalai

    It looks like an iron block/head and doubt ever seen life in a helicopter
  3. mark775

    mark775 Guest

    Cool. Or something like this in four or six
    And parts are available.
  4. masalai
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    masalai masalai

    Now that is a cool aircraft flat 4 (or as subaru and porshe? call it "a boxer" engine) with glycol coolant/radiators? Aircraft engines have similar loadings to that of boats - - except I prefer diesels because of a fire risk....
  5. Paul aka watertaxi
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    Paul aka watertaxi Junior Member

    Definitely like the top mount alternator and top mount starter. It's no fun replacing the starter blind under the engine and unusually with no room to get in there. That's one of my least favorite jobs. Makes sense to keep electrical items high and dry for less corrosion in my book too.
  6. thudpucker
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    thudpucker Senior Member

    Wiki says it was an air-cooled engine for a Chopper and Tucker had a water jacket made for it. that's why it looks so weird. ALso he was a fan of GM engine and parts.
    Even though his car looks like he was a fan of Studebakers.

    Now that engine in the Mark775 post looks cool! Just what I woulda done if it'd been me!
  7. apex1

    apex1 Guest

    As mentioned above, the Porsche and Subaru boxers are doing the trick. And I cannot see individual heads on the Tucker.
  8. thudpucker
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    thudpucker Senior Member

    Apex, "Boxers"? I must be living under a rock. I'd never heard that term before. what's it mean? Square? Flat? ...?

    Here's some numbers on the Tucker engine from the guy who owns one;
    "The helicopter engine, which powered the Tucker could run for 1,500 hours without a rebuild, and exceeded every military specification required of it. At least one Tucker had 200,000 miles on the clock without needing a major repair.

    Hamlin's unmodified Tucker was rated at 103 HP at 2,000 RPM, while a 1954 Cadillac was only 87 HP at 2,000 RPM in dyno testing. A Tucker's engine put out some 372 ft. lbs of torque and the car had 0-60 times of 10 seconds. Not bad for a 4,200 lb car."

    I'd have a little trouble if you told me a Subaru can match 372 ft lbs of torque at 2000 Rpm.
    My 77 Subaru was a pretty good little 4X4 but it wasnt that torquey. My son nicknamed it War Mouse as it sounded like it would tear the ground up to get out of its own way, but in the end the phrase; "You can gear down a Mouse enough to pull a freight train" apply's to Subaru.

    The Subaru was my inspiration when I dreamed up the boat engine with the dry exhaust and a water cooled heat shield between the engine and the Hull.
    There were lots of things I liked about that little engine.

    But you have to admit this Tucker is a whole herd of Big Black Wharf Rats on a tread-mill compared to the Subaru's four little white mice in a busy wheel.
  9. mark775

    mark775 Guest

    Prefer diesels?
  10. mark775

    mark775 Guest

    The new series Impreza STi Version 7, with a static compression ratio of just 8:1, AVCS and a large IHI RHF5 turbocharger, punches out 206kW at 6400 rpm and 373Nm at 4000 rpm. And if that’s not enough, an update was released in December ’01 bringing 384Nm, another update came in late ’02 bringing 394Nm and yet another update in late ’04 brought a huge 412Nm. A slightly larger intercooler, a twin-scroll turbo, aluminium pistons and other internal mods are incorporated in these running changes. The current STi generates 422Nm of torque.
    Bone stock. Enough torque for ya? The EJ20 turbo debut in 1989 proved Subarus to no longer be just a water-cooled copy of a bug.
    The kids are getting much more out of these with after-market goodies and widespread tuner know-how. My boy has a 2,400 lb. car with over 300 HP. and he's in a tame league. Subes are the power of choice for Oregon dunes sand rails;
    ...although we have built a light-weight one with snow-machine engine, a torquey one with an American V-8, a dog with a Saab, and bug driven ones.
  11. thudpucker
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    thudpucker Senior Member

    I dont know Mark. I just dont know a NanoMeter of Torque from exactly what two White mice can do in NanoFoot pounds.
    That Subaru engineering looks good.
  12. apex1

    apex1 Guest

    Boxer engine Thud, means Boxer engine, like V8 means V8.
    the left picture shows a 6 cyl Boxer, the right a 180° V6 (no Boxer, although as flat.)


  13. mark775

    mark775 Guest

    Picture an actual boxer, hitting his gloved fists together. The opposed pistons work like that, hence "boxer". It is smooth as it is intrinsically balanced, like a V-12 and straight six. It is comparatively expensive to build and wide but fits into some car designer's ideals. Perfect for a plane, IMO perfect to fit under a low deck of a boat.
  14. kapnD
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    kapnD Senior Member

    Yes, the flat configuration is appealing to marine applications, where space is always at a premieum, but I think its a bad idea to have the exhaust routed out the bottom of a marine engine. Even with the use of a shield (isnt the boats bottom inherently water cooled?) the exhaust manifold, like all the other major parts that hang off an engine need to be readily accessible for inspection/repair, not to mention corrosion susceptibility being enhanced by hot metal hanging in the bilge water.
    Adapting various engines to marine use is always appealing, but to really be cost effective, you cannot beat a marine (or marinized if you prefer) engine built by a major manufacturer that comes with a good warranty and is a proven design. I will be the first to admit that not all (any?) marine engines are perfect, but an individual designer cannnot compete with the millions of dollars needed to do all the testing, research, and tooling associated with building a reliable and marketable product.
    All that aside, I have had great results in building and running flat VW and Corvair engines in buggies and street rods, and would love to get my hands on that diesel Subaru!

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    FAST FRED Senior Member

    One of the biggest hassles with marinizations of aircraft or other gas engines is many will use FUEL , as a coolant at max power.

    5 min at Take off power , 12 seconds in a drag race is a far different deal than 24/7 in a boat.

    That stated Gas engines are frequently superior to diesel if very modest loads are seen.

    A 400hp rated gas engine lives long and well at 50 -100 hp of load.

    An industrial 400 Hp diesel may suffer inefficiency , fouling , diluted oil, stack plugging and a quite short service life from long term under loading.

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