Gearbox/Counter rotaing engine question.

[antonywardle]

Hi

Just for interests sakes.

I understand about getting a pair match outboards that have different props on them that spin different directions

but I don't understand how it works.

Does the outboard gearbox go the same speed in either (forwards/reverse) direction? If thats the case then

I'd guess that the all that would happen is that one outboard would be in forward and the other in reverse with

a different prop.

If its like my car where reverse is lower geared than say first, I don't know what would happen, unless they

have a whole different gear box.

While I'm on the subject of gearboxes, why don't boats have gears like my car? Or do they and I don't notice it?

I'm guess at some point, no matter how fast you spin the prop, you won't go any faster and the outboards are designed

to get the prop to this speed. It would be good to be able to drop the rev's down and keep the prop spinning at the

correct speed. Maybe the friction of the water would prevent this?

cheers

[BWV]

Ok, it works by have both gearboxes spinning in opposite direction expressed as "standard rotation" and " counter rotation" each corresponding gearbox is the fitted with a left handed or right handed propeller.

No one isn't in reverse, they are both going forward. They are different gearboxes but same ratio. They differ by the way the gears and thrust bearings are placed. If you try and run it in reverse to go forward you will destroy the gear box pretty quickly.

Boats don't have gearboxes like cars because they are under constant load, boats are always going up a big hill. The faster the prop spins the faster you go.

[antonywardle]

Brilliant answer thanks

it makes sense now. Different gearboxes