Twin engine instalation & props

[jonny12t]

With a twin engine setup i have been told that the prop rotation should be the tops moving away. so looking at the stern, port side acw, starboard side cw. (as in pic)

Why is this? Can twins instalations be installed the other way around? if so what are the carateristics and differences between the two setups?

[Jon Fuller]

The way you have described, and in the drawing is considered the norm, and most stable setup. Some boats will run faster top speed with the opposite rotation (turning in) but depending on the boat, and ultimate top speed, that faster setup can be less stable, and prone to instability in roll.

It's a suck it & see situation.

[topgun]

Originally Posted by jonny12t

With a twin engine setup i have been told that the prop rotation should be the tops moving away. so looking at the stern, port side acw, starboard side cw. (as in pic)

Why is this? Can twins instalations be installed the other way around? if so what are the carateristics and differences between the two setups?

Running the props backwards to the norm can create stern lift which is sometimes needed depending on engine sizing/weights,this however can result in instability like Jon is warning against

[jonny12t]

thanks chaps, just what i was after

[jonny12t]

apologies, just realised i put this on trading post...... whoops