Driven direction for a stern drive

[oily rag]

Folks

This seems like a simple question which I can’t find the answer to, even after much online searching. My question is- can stern drives be driven by an engine in either rotational direction?

If not, which ones must be driven clockwise when looking at their input shafts from inside the boat (or which ones can be adapted with available gears to run clockwise)?

I have two (soon to be) marinised VW 1.9 tdi engines that I would like to fit to a cabin cruiser with stern drives that I have not yet bought. I can’t afford new stern drives. The engines still run clockwise (looking at the transom from inside the boat). I think that’s called right hand rotation? I really don’t want to reverse them if at all possible or use them ‘fan belt end’ next to the stern drives. Incidentally, I see plenty of discouragement about using marinised car engines, but after many years of running VW diesels I am a die-hard fan, I can readily sort out the cooling issues and I don’t intend to spank the engines. The gear ratio will be considered too before I buy.

All the info I can find suggests that most stern drives need what seems to be a more conventional counter-clockwise rotation input to suit their gearing? This would make sense given that the helical cut bevel gears I've seen in exploded views should be driven only one way by design. The only stern drive I can find which is stated as suitable for clockwise engine input is Enfield but does anyone know of others, if it matters?

I know that the output of a stern drive can be reversed, but of course that is not the same thing as the input direction.

Thanks in anticipation.

[anthony goodson]

Most stern drives turn the same way as your engines , which turn the same way as most engines, which turn the same way as most sterndrives.

[gonzo]

That is a standard left hand rotation engine. Depending on the drives you may need a matched (left and right hand rotation) or the type that can turn either way(VolvoPenta, OMC)

[oily rag]

Thanks Gonzo. So Volvo Penta and OMC stern drives can be driven right handed (clockwise) or are they left hand driven, and can be swapped internally to change the output rotation. Are there any sterns drives that can be driven right handed?

[anthony goodson]

oily rag ,I read your post carefully .including the last sentence ,my reply was clear unequivocal and correct ,it needed neither clarification nor embroidery, just endorsement ,now you are confused, I wonder why?

[gonzo]

VolvoPenta and OMC are designed for standard (left hand) engines. Engines are rated from the flywheel rotation.

[oily rag]

Thank you Gonzo. I wish all the contributors would be as constructive. Please bear with me. So I’m not lost, is this right or left hand engine ?:

[gonzo]

That is a left hand, standard, rotation engine.

[oily rag]

Ahhh that's good because my engines rotate that way. I got the idea that was 'right hand' somehow after reading some rubbish, hence my confusion. Full steam ahead. Thanks again for your help Gonzo. And thank you Anthony for your help.