Prop bolt length for C85

[d.grimm]

Well the new engine has a flange shaft, (unlike the taper shaft I used to have) and I need some new propeller bolts for a Sensenich Wood W72GK44 propeller.
Anybody know the length?
Thanks,
Dave

 

[Ed Brown]

Sorry Dave, I don't remember the length of my prop bolts.

Glad to hear you're making progress in getting your Vagabond back in the air.

Ed

 

[Steve Pierce]

AN6H-40A is what I used on the C85 powered Luscombe with a Sensenich wood prop several years ago.

 

[d.grimm]

Thanks Steve,
I had -42's in there before and I figured they would be a little shorter,
just didn't know how much.
Dave

 

[BrettL]

The AN6H-41A is the correct length for a standard wood propeller hub. These are the same length as the original bolts that are specified in the parts manuals for the A and C series (and O-200) Continentals. The original Continental bolt is part number 24768 and differs from the AN bolt in having a minimum of 7/8" of thread vs. 9/16" on the AN bolt (to avoid bottoming the threads in the flange bushings, resulting in false torque), and apparently being of different steel composition than the AN bolts (3140 vs. 8740). Unfortunately the 23768 bolts are difficult to find. Sensenich recommends the AN6H-41A.

Don't forget the part number 35956 moisture impervious plate, the part number 3991 propeller hub flange (goes on the front of the hub over the moisture impervious plate), and the part number 401507 washers under each bolt. Missing any of these parts will make the bolts too long, and will likely effect the life of the prop.

 

[d.grimm]

Thanks Brett,
Believe it or not this is the first flanged crank engine I've owned.
Dave

 

[BrettL]

I've seen it done wrong too many times. When I got my Vagabond it was missing the moisture impervious plate, and had 1 bolt that appeared to be a AN6H-43 or 44 with a number of washers under it, and 5 bolts that had no markings on the heads, with about 1/4" machined off the shank just above the threads, and the safety wire holes in the heads that appeared to be hand drilled.