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FP Prop bolts?

N941WR

Legacy Member
It is time for me to buy the prop bolts but I'm having a difficult time finding the right length.

My O-290-D2 takes 7/16" diameter bolts (AN6H)

The length should be the sum of the backing plate (1/2"), Spacer (2 1/8"), the prop hub (Catto 4 1/4"), and a washer & spinner plates (1/8") for a total grip length of 7".

Vans don't list such a bolt on their site and neither does Aircraft Spruce.

Two questions:
1) Does my length sound like it is in the ball park?
and
2) Where can I find the right bolts?
 
Update for future searches

I called Sam at Sabre, what a knowledgeable guy!

Due to the length required for my Catto prop he pointed me back to Vans. It turns out I missed a few things in my length calculation and he recommended an 8" bolt.

They go $20 each and I needed six of them. OUCH!
 
I think you will find that the price of prop bolts doubles when you go over 6". I had the same situation when I went to the Catto prop. I think I bought my bolts from Saber.
 
Mel said:
I think you will find that the price of prop bolts doubles when you go over 6".
I was surprised to find that you bolt all this stuff together with six long bolts. I would have thought you just bolted the extension to the hub with one set of bolts and then bolt the prop on to the hub with a 2nd set.
 
2nd set required on mine!

Got my spacer and bolts from Sabre, Catto prop on a 180+ HP. It required two sets of bolts, one for the spacer, one set for the prop. Wonder if it's dictated by HP, just a different spacer or what??
 
On my Catto, IO-360 aircraft... I have a 2 1/4 spacer from Sabre and then ordered the regular bolts from Van's. Works fine and prop still firmly attached after about 3 hrs.

Best,
 
Bill, I think the difference is that we have the old longer cowling that requires a 4" extension. We have seperate bolts for the extension and prop.
 
new prop extensions

Saber has in fact produced new prop extensions for even 2.5" extensions. They are called 12 hole extension and are now carried by vans. The advantage is they require shorter bolts that, as you see, can reduce the price considerably.
 
Must have the new 2.5"!

Definitely 2.5" spacer, CS (or short), cowl. And the bolts were cheap, even for two sets!
 
Update

The bolts from Van's arrived on Saturday and today I tried to install them.

Wrong size, duh!

Looks like I need 3/8" bolts, which I couldn't find.

Called Sam at Saber and ordered his set up. They should arrive by Monday at the latest.

The the bolts, prop extension, and crush plate are all boxed up and will be returned to Van's in the morning.

Not a big deal.
 
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