I know this is a basic question and I should know but I'm confused. I figure I'm running the engine in the correct direction as I am getting thrust behind the prop. If it was running in the wrong direction, it would be pushing air out the front of the prop, correct?

Also, which direction should I prime an engine before starting it, when facing the prop, and which direction should the engine run in from the same location, facing the front of the engine? My starter is turning the prop counter clockwise when facing the front of the engine.

Last, what can happen to an engine running in the wrong direction for a short and also for a long period of time?

Thanks in advance.

Cappaj1,
When standing in front of the engine the prop turns counter-clockwise. When you prime the engine you should turn over the engine by hand in a counter-clockwise direction, the same as it runs. I've had engines run for several minutes running backwards and have had not ill effects. The biggest issue you want to watch out for when an engine is running backwards is having the plane "backup", if you don't have a good hold on it the prop could back right into your hand.

Ken

When in front of the engine/airplane using a starter the running direction will be counter clockwise in virtually all cases.

Many engines can start in the other direction most often when using a chicken stick but they will not run properly and should be allowed to stop or shut down. Using a starter your direction will be counter clockwise. Some folks in starting with a chicken stick will bump the propellor backwards and the engine will kickinto the right direction.

To run the other direction involves a major induction port timing change which means either a decicated reverse running crankshaft or some engines with rotating front bering cases can be rotated 180 degrees for reverse running. One of these engines would also require a reverse pitch prop normally used for a pusher aircraft but installed backwards from that application.

John

Better check again John. To make an engine with removable front end run backwards, you only turn the front end 90 degrees counter-clockwise.

And then there was my Prop Rod!!

Did you get your engine back, Jim?

Yes thank you HP you are of course correct and that was my careless error. I suppose even that option is becoming more moot these days with very few manufactured that way.

John

Indeed.

No, I called Hobby Services on Wednesday and they said 'We received your engine on Tuesday and it hasn't been looked at yet. It will probably be looked at tomorrow, or Thursday'. Well, 'tomorrow' is 'Thursday' so I'll take either one I guess .

If you haven't already done so, you should look at the pitch of the prop and know what direction the engine should turn. Make sure you know the little basics like that, you wouldn't want to put a prop on backwards or something like that.[sm=thumbs_up.gif]

So maybe the day after yesterday? I can't wait for you to get flying again.

I have a K&B .61 engine with a reverse crankshaft. I'm saving this for a pusher A/C I have in mind and I'll be able to use standard propellers then. Gonna need to remember to reverse my starter though. The engine has a pump so I can leave the tank forward of the CG for balance.