Flywheel Identification

[JTR249]

Here are a few photos of two sides of a flywheel I recently acquired and thought they were 741B sides. The PNs do not match the 741 manual, which are 76080 right side and 76082 left.
These are 74245-74247 which leads me to believe they are for a 74" motor. Just a guess.
I would appreciate any opinions as to what they could be.
-JR Unknown Flywheel Diameter is close to 7 and two fourths inches. 1.JPGUnknown Flywheel PN 74245-74247 and a capital U in a circle. 5.JPGUnknown Flywheel PN View of entire Side--both are identical. 4.JPG

[JTR249]

Last two.
-JR Unknown Flywheel Side View 3.JPGUnknown Flywheel Width measures about 1 and one fourth inches. 2.JPG

[PaulCDF]

JR
How about the timing marks: Chief used "$" (On the money)
I believe the 741 used the Cent symbol (Can't seem to find it on this modern keyboard)

[T. Cotten]

I haven't a clue, JR,..

But measuring the stroke would be a clue;

Eye-balling with a ruler the center-to-center of the pin holes should do,

....Cotten

[JTR249]

I did not see any markings after a little wire brushing. I will measure and re-post.
-JR

[JTR249]

In the next-to-last photo, I measured and I see 3 and 2/16" center to center.
-JR

[tgarcia]

Those are scout of sorts,the o.d. on a chief is just over 8". but your pin height measurement isn't right,chief is just shy of 2 1/4" for 74" and like 2.4" for 80"so 3 1/8 is not going to be correct.if I remember correctly scout is 1 3/4 pin height for 45".

[JTR249]

I don't know what they could be. This is the second time this has happened. I bought them thinking they were 741 flywheels, which are not this big. I mean for flywheels these things are huge, which is why I doubted if they were 741. I have a set of 741 flywheel sides made from Z metal and they are much smaller than these.
-JR

[pisten-bully]

JR...looks like 7 5/8" o.d. but your ruler also isn't centered on the shaft hole in the photo. Take a look at Truett and Osborne's specs for flywheels:

IMG_2511.jpeg

[JTR249]

I would say it is most likely a 1920-1931 because they were much larger weren't they?
My measurement was not photographed. The photo with the ruler is just to show diameter of the wheel.
I took a tape measure and measured like Cotten said, vertically from the center of one pin hole to the center of the other pin hole. That's only off by one sixteenth according to the chart.
I'll take a photo soon to show the difference when placed beside the Z metal 741 wheels I have.
Thank you.
-JR

[JTR249]

Here's a couple of photos to illustrate just how much larger these are compared to Z Metal flywheels.
(Obviously to those of you who can identify Z metal wheels, these are missing metal around the sides and top of each wheel. Flannagan actually pointed out in a humorous way--hey, John, there's supposed to be metal continuously around the flywheels! I had a good laugh at my attempt to cut corners on cost. Most likely never again.)
-JR Unknowns on Left and Z Metal on Right.JPGZ Metal Flywheel inside a Larger Unknown.JPG

[tgarcia]

I could be wrong but I thought the pre 34 flywheels had "windows" cut in them around the sides of the pin supports.

[tgarcia]

Like this 1925 set

[JTR249]

Well, based on the chart above, the '34-'42 is also 3 1/2" stroke. I guess it could be for that range of years, though I thought because they are slightly larger than my Z metal comparisons that were from an earlier year, just don't know how much earlier. They are not Z metal, so I thought that might help identify a more specific range as pre-war. The description from the seller said they were Army. I don't think the seller knew much about them either.
-JR

[JTR249]

1936 to 1938 Flywheels.jpg I was digging through the manuals today and I found the match!
In the Indian 1936-1938 pats manual on page 6, there it was---74245---74247-- heavy type flywheel.
Here's the page.