Michigan Mystery prop

[retiredoz]

Scrounging thru my stash I found an old Michigan two-blade brass prop. LH, approx 7 1/2 dia. would fit a 1/2 in propshaft. The number scratched on it is OB435, which doesn’t match any of the known-to-me Michigan ID codes. The 30’s catalogs available in the IS were not much help. I suspect a Muncie application, but does anybody have a guess what those numbers might apply to ?

• This topic was modified 2 years, 4 months ago by retiredoz.

[Mumbles]

OB is a Muncie model so would searching 435 go anywhere?

[retiredoz]

My bible only goes back to ’38, and Hunn’s book is even later. However, since the 4-hp for ’38 is cleverly a 438, similarly the ’39, I’m going to assume this is for a ’35 4-5-6-hp twin. It does have an ‘R’ punched on on the hub, which makes little sense unless this was some kind of racing prop ? I have little info on what Muncie was up to in the ’30s…

[Mumbles]

Well, isn’t this interesting as all the old Michigan prop lists I see show part numbers starting with an M for Muncie, Neptune Motorgo, and Waterwitch OB series of motors.

OB could stand for Otterbine but I believe they only made small Briggs powered jet drives.

[retiredoz]

I think I got it. It’s for a Muncie/Neptune Junior Twin, 8X7, which looks right. Looks like the OB prefix got dropped about ’37 or so.

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