O-300B engine

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bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

Re: O-300B engine

Post by bagarre »

After all my reading on the Aeromatic, I think it was a great prop that was misunderstood and died out cuz a metal prop is considered zero maintenance.

It takes a bunch of flights and counter weight changes to get dialed in correctly which requires an A&P to do. PITA

Yes, it loses performance when you change operating altitudes by 5,000 or so feet but how often does the AVERAGE 170 pilot take off from a field a sea level and need short field performance at 5,000 feet in the same flight?
I can't remember the last time I FLEW at 5,000 feet, let alone landed.

People make it sound like you need to carry a pocket full of shims and adjust the prop cuz your DA changed. Thats simply not true.

How much is the performance degraded? Probably no worse than if you had a cruise prop at 5k feet vs a climb prop.
The -2H override requirement was so that Cessna could maintain a service ceiling of 12,000 feet for the plane. OK, I've never ever ever flown above 7,500 feet with any propeller.

Wood rot and throwing blades? Debunked and not a concern with a well serviced prop.

The kicker for me is, without the -2H motor (rare) and the Hi-Cruise hub (even rarer) - you need a field approval (OMG approve a prop swap???) to install it.
And that was just too much on top of the $5k or $6k for the prop - just to find out how it would actually perform.

and I keep 81D outside which would be hell on the wood blades.

So, I decided to keep it simple and install a Continental IO-360 instead 8O
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Bruce Fenstermacher
Posts: 10318
Joined: Tue Apr 23, 2002 11:24 am

Re: O-300B engine

Post by Bruce Fenstermacher »

Aryana wrote:
Bruce Fenstermacher wrote:... It is neither a good climb nor a good cruise prop...
The testimonial you gave earlier about it being a compromise but not really superior in any given flight phase is what made me say it sounded like a dud. I wasn't trying to put words in your mouth, but rather sharing my opinion based on the description you gave.
I was talking about the McCauley two position prop based on one flight demonstration.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
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c170b53
Posts: 2527
Joined: Mon Apr 22, 2002 8:01 pm

Re: O-300B engine

Post by c170b53 »

I can always be used as a bad example.
No I don"t think so , that's my position around here, get your own! :D
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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blueldr
Posts: 4442
Joined: Thu May 02, 2002 3:16 am

Re: O-300B engine

Post by blueldr »

David Ross,
It is not at all uncommon out here in the far west to have rather gross elevation changes on a single flight. Our mountains are closer and higher than most of the eastern part of the country.
It was my observation that an elebvation change of about three thousand feet was enough to have an effect on the prop seting of the Aeromatic prop.
The prop that I had was an experimental model that had been made for the Air Force and had a hub designed for a #10 SAE splined prop shaft on the Lycoming O-435 engine rather than a flanged shaft of the more common civil engines. It did not have any provision for any hydraulic operation and was totally isolated from anything other than the counter weghts and centrifugal twisting moment.
Those Aeromatic props seemed to became very common on the Stinson 108 seris of airplanes powered with Franklin Engines using a flanged prop shaft.
BL
bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

Re: O-300B engine

Post by bagarre »

blueldr wrote:David Ross,
It is not at all uncommon out here in the far west to have rather gross elevation changes on a single flight. Our mountains are closer and higher than most of the eastern part of the country.
It was my observation that an elebvation change of about three thousand feet was enough to have an effect on the prop seting of the Aeromatic prop.
The prop that I had was an experimental model that had been made for the Air Force and had a hub designed for a #10 SAE splined prop shaft on the Lycoming O-435 engine rather than a flanged shaft of the more common civil engines. It did not have any provision for any hydraulic operation and was totally isolated from anything other than the counter weghts and centrifugal twisting moment.
Those Aeromatic props seemed to became very common on the Stinson 108 seris of airplanes powered with Franklin Engines using a flanged prop shaft.
That's a good point. As an East coast pilot, I'm always looking down on the terrain.
But for someone like me, the prop could work nicely.
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