Fixed-pitch spinner, front bulkhead bolt holes

[Paul Eastham]

O-320 engine, fixed pitch metal prop with 7/16 prop bolts. The front bulkhead (ostensibly part "S-605 SEN") has 3/8" holes -- too small for my prop bolts. Am I supposed to drill out these holes, or was I given the wrong part?

My back bulkhead had properly-sized holes...

Too bad I don't own a 7/16" drill or reamer.

[az_gila]

Originally Posted by Paul Eastham

O-320 engine, fixed pitch metal prop with 7/16 prop bolts. The front bulkhead (ostensibly part "S-605 SEN") has 3/8" holes -- too small for my prop bolts. Am I supposed to drill out these holes, or was I given the wrong part?

My back bulkhead had properly-sized holes...

Too bad I don't own a 7/16" drill or reamer.

Paul... I'm switching to a O-360 from an O-320 and Sensenich told me that my O-320 spinner was OK to use, and to just go ahead and drill out the holes, in my case, from 7/16 to 1/2.

It should be easy to do, just use your (or borrow one... ..) Unibit drill.



gil in Tucson

[szicree]

One thing to keep in mind about unibits, they often produce a hole that is not concentric with the original. To avoid this, put the part in the drill press (not running) and lower the unibit through the existing hole to center things. Clamp the part down, drill to proper diameter. Repeat.