OS .91FX in a .60 sized bird

OS .91FX in a .60 sized bird

Post by Sed » Sat, 28 Aug 1999 04:00:00



I just read a great review on the OS Max .91FX engine in RCM.  They report OS
crammed .91 c.i. in a .60 sized engine.  It's reported to make 2.7 hp, a big
increase over most .60's.  Has anyone tried to put this in their heli?  Think
it would work in my 60 X-Cell?
 
 
 

OS .91FX in a .60 sized bird

Post by MArmitstea » Sat, 28 Aug 1999 04:00:00


Quote:

> I just read a great review on the OS Max .91FX engine in RCM.  They report OS
> crammed .91 c.i. in a .60 sized engine.  It's reported to make 2.7 hp, a big
> increase over most .60's.  Has anyone tried to put this in their heli?  Think
> it would work in my 60 X-Cell?

SEd6,
     I haven't tried an OS91 in a heli but i once tried a Super Tigre
90,which is the same bolt pattern as their 60.
    To do the job succesfully you need to change the gear ratio to suit
the lower top end revs that the 90's (and aero engines are tuned for).
 If there is insufficient cooling area (finning) on the cylinder head
this will usually cause problems too.Finally the 90 will tend to make
more vibration than  the 60 on the combustion (firing) stroke.

Martin

 
 
 

OS .91FX in a .60 sized bird

Post by Doucours » Sun, 29 Aug 1999 04:00:00


the 91 FX is an airplane motor and i dont think the carbarator on it will work
very well on the heli, with a different carb it might work if the fan will fit
the 91 crankshaft.
 
 
 

OS .91FX in a .60 sized bird

Post by vari » Tue, 31 Aug 1999 04:00:00


I have one and tried it. The remote needle valve leaked air, and generally
ran pretty poor. Another person told me he tried it with a different carb
and it also was not up to the job in a heli. Don't waste your money.
Joe

Quote:
>the 91 FX is an airplane motor and i dont think the carbarator on it will
work
>very well on the heli, with a different carb it might work if the fan will
fit
>the 91 crankshaft.

 
 
 

OS .91FX in a .60 sized bird

Post by CJ » Tue, 31 Aug 1999 04:00:00


Quote:

> I have one and tried it. The remote needle valve leaked air, and generally
> ran pretty poor. Another person told me he tried it with a different carb
> and it also was not up to the job in a heli. Don't waste your money.
> Joe


> >the 91 FX is an airplane motor and i dont think the carbarator on it will
> work
> >very well on the heli, with a different carb it might work if the fan will
> fit
> >the 91 crankshaft.

I was told this tip. "Put a piece of fuel tubing on the needle valve"