Weights of engine installations

Discussion in 'Aviation' started by Shortround6, Oct 19, 2012.

  1. Shortround6

    Shortround6 Well-Known Member

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    In another thread a discussion came up about the "efficiency" of a couple of opposing engines. I don't have the information on the DB engines in the 109 but from "AHT"
    the figures for the P-40 are as follows.

    model.....................P-40........P-40C...........P-40E...........P40F.............P-40N

    Engine section..........293...........298.............345..............349................335
    engine....................1345.........1357............1307............1518..............1340
    engine accessories....114...........114.............106..............114.................92
    eng. controls.............22.............21..............26.................8..................29
    propeller..................342...........337.............383..............386................417
    starting...................42..............46...............43...............34.................45
    cooling....................291.5........291.5...........294...............306..............235
    lubrication................59.5...........62...............61................64................92

    And fuel system........171.............420............425...............437..............366

    All numbers are in pounds.

    The engine section includes the cowling/engine covers, engine mounts, radiator/oil cooler ducts and adjustable flaps and intake duct.

    Engine accessories can include pumps (vacuum, air, hydraulic, gun sychronizers, exhaust stubs and other bits and pieces. Exhaust flanges are included in the dry weight of the engine but the exhaust pipes that are welded to them are not. The flanges,gaskets, and nuts are supplied with the engine. the Exhaust stubs are fabricated and attached by the airframe maker.

    Starters are a combination electric and inertia in this case, the planes without electric starter (hand inertia only) had a starter weight of 8lbs.

    Generator is in another category, "electrical".

    Fuel system weights jump so much because of going from unprotected tanks to protected tanks and perhaps even changing type of tanks. Fuel system weight (tankage) is the weight that will change the most from type of airplane to type of airplane. The weight also includes piping, valves, and any auxiliary or transfer pumps.

    Different companies and even the USAAF sometimes placed certain components in different categories at different times so one does have to be careful when making comparisons.

    I also don't get exited about differences of 1-3% in a given category as that may be just normal production tolerance.
     
  2. wuzak

    wuzak Well-Known Member

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    I understand that was common for Allison applications - including manifolding for turbos - but was it true of Merlins?

    Rolls-Royce spent a lot of time working with ejector exhaust shapes. I always assumed that they manufactured and supplied them. If they did, was it also th ecase for Packard supplied Merlins?

    What of the radial engines? Did the airframe manufacturers sort something out themselves, or did the engine manufacturer do that?
     
  3. wuzak

    wuzak Well-Known Member

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    I make the totals (not including fuel system) at:

    P-40: 2509
    P-40C: 2526.5
    P-40E: 2565
    P40F: 2779
    P-40N: 2585
     
  4. Shortround6

    Shortround6 Well-Known Member

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    There may have been collaboration between the engine makers and the airframe makers but the dry weight never included the exhaust system. F6F and F4U used different exhaust systems. The R-2600s in the B-25 used different exhaust systems than the A-20 or TBF. Or look at the exhaust on a Fairey Barracuda (caution use dark glasses ;)

    While you need an exhaust system the fact that they could vary so much from plane to plane meant it is hard to compare engines including exhaust systems. Everybody knew that flame dampening exhausts would be heavier than plain exhausts no matter which engine was used for example.
     
  5. stona

    stona Well-Known Member

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    You can buy a brand new manufactured set of 12 exhaust stubs for a Merlin engine for £1000. They are still made (to order) and are not a difficult piece of engineering. A single beat up wartime example,suitable for display rather than use,will typically set you back about £50,so that's pretty good value.

    I don't know who manufactured them during the war but see no reason why it would have to have been Rolls Royce themselves.

    Cheers

    Steve
     
  6. wuzak

    wuzak Well-Known Member

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    Quite possibly made by someone for Rolls-Royce to Rolls-Royce's specifications?
     
  7. stona

    stona Well-Known Member

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    #7 stona, Oct 20, 2012
    Last edited: Oct 20, 2012
    A distinct possibility. It's only fair to repeat that I don't know who made them but any competent engineering firm with the relevant pattern could have done so. There were (and are,despite what some would have you believe) plenty of such firms in the UK.

    They were made from 321 Stainless Steel (AMS 5645) which is not difficult to work with or weld. Certainly no "rocket science" involved.


    Cheers

    Steve
     
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