Propellor Boss fixing holes.

Nigel Ramsay · Post by **Nigel Ramsay** » Wed Jun 30, 2010 6:40 pm

VW or Continental/Lycoming Ron? Here for example is some info from Great Planes for one of their motors:

Prop Flange Diameter 5" 5" 5" 5" 5" 5"
Bolt Holes in Flange 6" 6" 6" 6" 6" 6"
Prop Flange Bolt Pattern, o/c 4" 4" 4" 4" 4" 4"
Prop Pilot Diameter 2" 2" 2" 2" 2" 2"
Prop Pilot Depth .375" .375" .375" .375" .375" .375"
Prop Bolt Diameter .312" .312" .312" .312" .312" .312"

These apply to a number of power outputs, and are all the same so a fair bet that this is the VW set-up.

cardiffrob · Post by **cardiffrob** » Thu Jul 01, 2010 7:35 am

Continental.
4.375 inch pcd, 3/8 bolts into 5.8 dowels

Lycoming.
4.75 inch pcd and the same bolt/dowels.

I got this from a text book. Not sure which "SAE" they are.

Rob Swain · Post by **Rob Swain** » Fri Jul 09, 2010 12:01 pm

cardiffrob wrote:Lycoming.
4.75 inch pcd and the same bolt/dowels.

Lycoming bolt sizes depend on the engine model / power. From my limited experience they can be 3/8", 7/16" or 1/2".
Source: the Sensenich order form on the Van's website.

Anybody asked Chris Lodge about standards and sizes of prop boss?