Propeller ID

[DustyBritches]

I have a WWI 9'3" oak propeller with faint Paragon decals. The markings are right hand, 9'3"X6.75" and SO orSC 6752, stamp of a four blade propeller with 0 or U in first blade, S in second, A in third, and 76 in fourth. There are eight holes 3/4" in diameter. Photos attached.
The propeller looks very similar to the Curtiss R4 on this site.
Can anyone give me insight on the identification of this propeller?
Thx

[Dave]

You really can't rely on appearance, as there were literally hundreds of models that looked the same but were for completely different aircraft and engines. It's also unlikely that your 9'3" prop was used for the same R4 application, which was 9'6".

Are you sure about the 3/4" bolt holes? That size isn't very common. See if you can match the hub dimensions to something on this chart.

[DustyBritches]

Propeller ID

Dave,
I made a few more measurements:

Center Bore Diameter 3 1/4"
Bolt Hole Circle 8"
Number of Bolt Holes 8
Hub Thickness 5"
Bolt hole Diameter 11/16"

I appreciate your help.

[Dave]

None of those measurements seem to fit the common hubs mentioned above. It may have been an oddball engine of some kind, but it's going to be hard to know which one.