reversing an engine
 

ok, this question is for the ducted fan guys..

i have a new in box OSVRdf engine 90, or is it the 91.... keep getting that mixed up with the NIB rossi engine. anyway question is.

I want to use this engine in an aircraft with a prop, pusher set up. How do I get to run this engine in the opposite direction????


Am I right? if memory is correct, I take the four screws out of the front housing and turn the housing 90 degrees? and if so, which direction?



Thanks for the help

Mark

RE: reversing an engine
 

Why do you want it to run in reverse as opposed to using a pusher prop? Can't you find the prop you need?

RE: reversing an engine
 

a few of use, picked up a bobcat 50. I got mine for Fathers day from my kids, it's the only jet they can afford.....lol

we are having a hard time with pusher props, same with the other guy who is running an ASP 90. can not find the right pusher props.

so if i can reverse the running of this engine, props will NOT be an issue...

Mark

RE: reversing an engine
 

As far as I recall you should be able to reverse the engine direction if the part of the crankcase that holds the carb is a separate part held with screws, it needs to be rotated 90 degress CC looking from the front of the engine, but of course this will only work on FRONT CARB engines only, again I could be wrong, you need to validate this, don't know your specific engine, the OS91DF has the carb in the rear so you cannot do it...

RE: reversing an engine
 

Make sure you put the prop on backwards too or it won't produce much thrust.... [&:]

RE: reversing an engine
 

I did it years ago with a Supre Tigre 61 or 90. I even tested the reversed engine using an identical pusher prop compared to a tractor prop on the same engine before reversing it.
It tached the same both ways.
I would think you could rotate the back plate with the rotory valve and accomplish the same thing.
Try it & let us know.

RE: reversing an engine
 

the OS 91 VRDF has a drum rotor driven by the crank pin. I don't think it can be done. I can't remember if the rotor only had one spot for the crank drive to plug into.

RE: reversing an engine
 

I had a bobcat 50 pusher with a rossi .81 ducted fan motor that I reversed. It was a rear intake engine so I had to turn the backplate 90 degrees instead of the front. It ran fine backwards. Open exhaust and tapped the case for a perry pump to keep the fuel flowing. apc 9x10 or 10x10 on 30% nitro. I don't know what it tach'd but it was almost scary. It flew fairly fast too, it was a fun plane.

RE: reversing an engine
 

Whassup, Mickey?
I thought I might run into you at the Southwest in Waco last weekend.
Did you make it?
JA

RE: reversing an engine
 

I have used two different 45 engines on my Bob Cat running backwards. Rotate the front housing 90 degrees CCW. Works fine but the carb is substantially lower so tuning is different.

I am currently using a 50 engine with pusher props. Tuning is also different because the airflow across the engine is less. Ground run time is limited. I have had a few problems with the engine not coming up to speed on take off.

Bill

RE: reversing an engine
 

To reset the induction timing for opposite rotation on either front or rear induction, rotate the back/front plate (whichever has the carb on it) through 90deg against the required direction of rotation.

Gordon

RE: reversing an engine
 

Hi,

This is the modification I made to run a standard prop on my OS .61FSR engine, it works!

John