REFLECTOR: Exhaust systems

[John Dibble]

Ronnie,

What fuel (octane) do you use?
What is the compression ratio for your engine?
What is the minimum recommended octane for your engine?

I feel like I must be from another planet.  The highest EGT temperature I have seen
(during takeoff, max power, Franklin engine) is 970 degrees.  Maybe my RMI monitor is
off, but my other temps seem right.  My IVO prop is 9.5 inches from the 3 into 1
exhaust that exits striaght back.  No indication of overheating, just the light "dust"
that wipes off.

John

Ronnie Brown wrote:

> Not only true with the M/T but also any three bladed prop.  No way to clock
> it such that it misses the exhaust, even for 4 cylinder IO 360's.  No
> pictures but I saw with my two beady little eyes a Velocity and a Cozy, both
> with 360's, both with Performance props, both had charred spots on one blade
> of the prop, looked like a wooden match that had burned, then extinguished.
> Not pretty.  The Velocity prop was returned to Clark, he pronounced it dead
> and unusable.  A two blade can be turned such that it misses, but as someone
> mentioned, there are only two positions that a three blade can be installed,
> both incur the wrath of the 1400 degree exhaust.
>
> I have a three blade Catto and forward exit exhausts.  No soot on the prop
> but some on the cowl.
>
> Ronnie Brown
> 173 Elite RG 55 hours