Wooden prop placement when parked.

[Tom Downey]

Tom, those lovely photos look like a Sigma-Tek metal-hub vacuum pump which uses non-canted vanes and is bidirectional. Most pumps (Airborne, Rapco, Tempest) use a graphite hub with canted vanes and are designed to turn in only one direction (e.g., 211CCW or 212CW). I've actually never seen a Sigma-Tek pump disassembled before, that metal hub and big ball bearing are impressive. No wonder they cost more. --Mike

No Mike, it's a regular old Pesco wet pump. you can buy them off E-bay for 40 bucks they are used on a lot of old aircraft. Any dry pump that uses the vane style pump uses centrifugal forces to hold the vanes to the pump walls, that force is not present while rotating by hand. Any pump that uses a canted vane when rotated in reverse, actually will push the vanes away from the walls as it is turned. They will only pump in one direction that is why the model says CCW or CW.

I've never had a sigma-tek pump apart either. I've only dealt with 1, it was on warrantee so I could not play with it.