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Loading on a gearbox

  1. Jul 31, 2008 #1


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    If 2 twin cylinder engines are geared together (90 degree cranks) and then a chain is coupled to the rear engine to a gearbox, would it be best to have a 1432 or a 1 and 3, 2 and 4 firing order,1 being front engine left 4 rear engine right ,to give least load on the gearbox, intuition tells me 1432 would be best (the load is spread) evenly, but would the main shaft bearing have a reduced life time.
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  3. Jul 31, 2008 #2


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    I assume you are talking about the dynamic loads from the engine, not the transmitted power from the shaft? An educated guess would be option B which would have more of a dynamic balance to it.

    Your main shaft bearings are journal bearings, correct? I can't see how you would have reduced life unless the coupling of the two increases the radial loading. Is there an option to increase oil pressure slightly?
  4. Jul 31, 2008 #3


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    There is an option for an uprated bearing but it requires some crank case mods, so i am not sure if it is justifiable, i may be able to increase pressure with an uprated oil pump, yes they are journal bearings.
  5. Aug 6, 2008 #4
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