Trying to identify a wooden propeller

[tramp]

Hi there,
I am trying to identify this wooden propeller. I used the chart provided and the measurements most closely line up with it having been used on a BMW engine. The only large discrepancy is the hub thickness. This propeller's hub thickness measures 4 5/8s inches.
There is no stamping on the prop and the blades were cut down. The overall length of the item is 36 inches.
I understand that without stamping, identification is very difficult...but would anyone be able to provide any additional help?

Many thanks,
Jonathan

[Dave]

Not much help, but I notice that it is a left hand thread, which is less common than right hand and sometimes (but not always) indicates a pusher application.

Even a "small discrepancy" in bolt circle diameter, center bore, or bolt hole size is probably enough to eliminate a specific engine. Hub thickness can vary a little bit due to normal expansion or shrinkage of wood with moisture, but the other measurements not so much.

[tramp]

Thanks for the reply, Dave.
I will post the measurements and perhaps that will help.
Thanks again,
Jonathan

[Dave]

Try to measure the "bolt hole circle" as accurately as possible. It's the diameter of the circle on which all of the CENTERS of the bolt holes rest and can be determined by measuring from one edge of a bolt hole, across the middle of the hub, to the corresponding edge of the exact opposite bolt hole. The discrepancy from the actual centers will cancel out using that method.

[tramp]

I checked the bolt hole circle and it measures at 6 3/4". If that's helpful...