Direction of rotation

I am considering a pusher jet and pusher props are available in limited sizes. For years it has been stated that engines with a bolt on front case can be run backwards.

Does anyone have experience running a ST .90 in reverse direction? Does performance suffer? Were there unusual problems?

Bill

I have heard that by rotating the front part of the crankcase 90 degrees to the right as you look at the engine from the front, it will run backwards. I've never actually tried it.

Dr.1

Exactly what I have heard but never encountered anyone that had experience. Sounds too simple and there might be lots of problems to be resolved.

Thanks.

Bill

....I believe you would rotate the front case 90 degree to the left looking
at the engine from the front. This was posted here at RCU, but I never tried it,
I just got a pusher prop and ran the engine in the usual direction.

FBD.

You can only reverse the older ST S90 and S90K's. There is no bearing housing to rotate on the present G90. It has a one piece crankcase

I believe you would rotate the front case 90 degree to the left

Oh, the OTHER left!

Dr.1

They have to be turned like the engine in Flyboydave's picture

Hello:

Yes, this can be done by rotation the carb in the direction shown in the photo. A guy in my club did it on what I think was an old OS 60. He had it flying a Bobcat with a tuned pipe and it howled.

Bye, Ian

I have done several older OS's and one ST 90. (Old style ST90 when they still had the bolt on front case) They run exactly like they do in normal rotation.

What size prop are you planning on running?

Thanks.

Bill

The last flights with the engine were with a 13 x 8 APC, which is probably a good starting point.

Bill

....yep. The 13-8's work good on the S.T. 90's, as well as the 12-9.

FBD.

I run a 13X8 on my Super Sportster 60. It has an ST 90 on it. Talk about vertical. (It gets off the ground pretty quick too)