[TASEsq]

Hoping someone can help me understand the difference in these 2 blade types.

Building a -14 with a 200hp Angle Valve (-C1E6) - this has counterweights. I am also installing SDS ignition.

A HC-C2YR-1BFP/7496 has come up for sale locally.


The hartzell manual says this prop is approved for the 180hp 360 series parallel valve with no counterweights. Also with some restrictions when using electronic ignition “Do not operate above 22 inches manifold pressure below 2350 RPM. Operation above 2600 RPM limited to takeoff only.”


Only the 7497 is approved for the angle valve with counterweights. (And lists no restrictions but seems to have been tested with dual mags only).


Is the approval a hard and fast rule? Or the lack of the approval is simply because they haven’t tested it? Or would it be an ill-informed decision to use this prop on a counterweighted engine?

It would be about 9k cheaper.

 

[Kaos2800]

The difference in numbers 7496 and 97 are blade model numbers. 96 are optimized for the lower 180 hp while 97 are for the larger 200 hp.

Honestly if you want to know the true impact, is this mechanically…. safe for me, safe for the aircraft, and if they say it’s safe what impact performance wise I’d call Hartzell.

They answered my questions quickly.

 

[TASEsq]

The difference in numbers 7496 and 97 are blade model numbers. 96 are optimized for the lower 180 hp while 97 are for the larger 200 hp.

Honestly if you want to know the true impact, is this mechanically…. safe for me, safe for the aircraft, and if they say it’s safe what impact performance wise I’d call Hartzell.

They answered my questions quickly.

I have sent them off an email to [email protected]

 

[skylor]

The difference in numbers 7496 and 97 are blade model numbers. 96 are optimized for the lower 180 hp while 97 are for the larger 200 hp.

Honestly if you want to know the true impact, is this mechanically…. safe for me, safe for the aircraft, and if they say it’s safe what impact performance wise I’d call Hartzell.

They answered my questions quickly.

Back before the 7497 Blended Airfoil blades existed, Hartzell would not certify or "approve" the 7496 Blended Airfoil blades for operation on 200 HP Angle Valve engines (or 210 HP -390) because of an apparent harmonics issue. Eventually they came out the the 7497 blades that were thicker and approved for the 360 and 390 angle valve engines.

Skylor