Sensenich Prop

[Waco01]

Changing from a wood prop to metal Sensenich prop (70CM6S9) on a 0-320 RV-4. Currently there is installed a 4 inch prop extension. Will the Sensenich prop work with this extension and what length prop bolts should be used ?

[Raymo]

If it is a Saber extension, call Sam with the prop thickness and he can supply the appropriate bolts.

He or others might know if it is a good idea to run a metal prop on the 4" extension. Weight and balance will need to be considered, of course.

[WAM120RV]

I have this prop on a 4 inch Sendenich extension. Its solid so the bolts are really long and expensive. Actually I am going the opposite way. The Sensenich is good but there is the 2600 limitation and it weighs a lot so there is a lot of money inertia on that 4 inch extension. If it's the solid extension the bolts are available from Sensenich.

[Waco01]

Thanks for the replies.
As far as the 4" sabre extension Van's website lists it as a possibility along with the Sensenich prop. Obviously changing from a wood to a metal prop will change the CG of the aircraft and needs to be taken into account.
As far as the prop bolts go Sensenich does sell the proper bolts but they are very expensive, $200+ to $300+ per set of six depending on length.
Actually a prop bolt is called a prop bolt when it has a longer thread length, other than that a standard AN bolt will work.
For a explanation of thread lengths go to www.sabermfg.com/bolts.htm. I would call what is explained there as "Prop Bolts-101".
Also bolts from Sabre are far less expensive as well as being much stronger.
Val K.
RV-8
N81vk