Propeller Selection

[omrsramsay]

My RV-3 came with a Sensenich 68x86 propeller, trimmed to 66". I want to replace it for better performance. With the Sensenich, I was getting about 150 mph or less at 2700 rpm, but I don't know what kind of performance to expect. The guy I bought it from claimed 175 mph. Props Inc recommends 68x68 for an O-320. Can anybody give me any recommendations? Thanks.

[rv7charlie]

Assuming fixed pitch wood or composite 2 blade prop,

Short answer: give a reputable prop carver *complete* and honest info about the plane, & they will know what to make for you.

Pitch numbers on the prop don't mean much, unless you're comparing it to another prop from the same mfgr, made in about the same time frame, using the same airfoils and profiles.

When I've tried to influence anything, I would ask for the largest diameter that I can safely run on the plane (for improved low speed thrust). I don't think that RVs can swing a big enough diameter to significantly hurt top end. The prop maker can work his magic on blade width, pitch, etc to match the airframe & diameter.

FWIW,

Charlie
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