Prop spacer

[DaAV8R]

Can someome confirm the prop spacer dimension for O-360, RV-8, vans cowl, sensenich prop?

I called Vans and they said 2 1/4. I searched and found a post that stated 4".

I'm confused.

Thanks.

 

[Jaknjoan]

The 4 inch spacer goes way back, primarily before constant speed props were commonly being used. If you have an old fixed-pitch cowl from back in the 80s or 90s, your cowl may be long enough for a 4 inch extension. For many years now Van's has primarily been making "constant speed" cowls, and those use a 2 1/4 inch spacer. Both constant speed and fixed pitch.