Loading Gearbox: 1432 or 1-3-2-4 Firing Order?

  • Thread starter wolram
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In summary, the conversation discusses the best firing order to use for two twin cylinder engines that are geared together and coupled to a gearbox. Option B (1 and 3, 2 and 4 firing order) is suggested as it may have more dynamic balance, potentially reducing load on the gearbox. There is also mention of an uprated bearing and oil pump as possible solutions. The website provided has information and software that may be helpful in this situation.
  • #1
wolram
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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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  • #2
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?
 
  • #3
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.
 
  • #4

1. What is the purpose of a firing order in an engine?

The firing order in an engine determines the sequence in which the spark plugs ignite the fuel in the cylinders. This is important because it ensures that the engine runs smoothly and efficiently.

2. How does the 1432 or 1-3-2-4 firing order work?

In this firing order, the first cylinder to fire is number 1, followed by cylinders 4, 3, and 2. This sequence is repeated throughout the engine's operation. It is known as the "evenly spaced" firing order, which helps to balance the engine's power and reduce vibrations.

3. What are the benefits of using the 1432 or 1-3-2-4 firing order?

There are several benefits to using this firing order. It helps to improve engine balance, reduce vibrations, and increase fuel efficiency. It also allows for a smoother and quieter operation of the engine.

4. Are there any disadvantages to using the 1432 or 1-3-2-4 firing order?

One potential disadvantage is that it can lead to a less responsive engine at lower speeds. This is because the firing order does not alternate between cylinders on opposite sides of the engine, which can create a slight delay in power delivery.

5. Can the firing order be changed in an engine?

Yes, the firing order can be changed in an engine. However, it is not recommended unless there is a specific need for it. Altering the firing order can affect the engine's balance and performance, and may require other modifications to be made to compensate for the change.

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