Prop Hub Torque

[Jer29_11_13]

Hi all,

I'm new to this forum and just bought a fiberglass airboat with a Buick 400ci engine.

The prop and hubplate were not mounted and I was wondering how much torque should I use to mount the hub and how much torque on the bolts that secure the wood prop? There's a separate plate that sandwiches the prop to the hub.

Thanks for any assistance!

Fred

 

[swampjet]

Fred,
The torque for a wood prop is usually 35 ft lbs. Start at 20 lbs and work up to 35. Also tracking a wood prop is important. It is where you clamp a wire to the transom , as the prop blade comes around (hand turning of course), the wire should barely touch the edge of each blade at the same place. I hope this helps.

Bob

 

[Jer29_11_13]

Thanks Bob,

But what about the hub plate bolts that attach to the flywheel plate of the engine, what should those be torqued at?

 

[swampjet]

Fred,
I think what your talking about is the adapter that goes between the motor and the prop. Those bolts get torqued the same as engine manufactures specs for a flywheel which should be (?) also 35 ft lbs. Some are different. The reason of only 35 ft lbs on the cover plate is that more will crush the wood. If the wood crushes before 35 then the prop may be weak or rotting on the inside.
Good luck with your new ride and WELCOME to the site.

Bob

 

[Des Moines Boater]

Here's a site that might help on torque values for most bolts. The manufacture's recommendation is always the one to follow but if you don't know try one of these numbers. Most bolts should be oiled before torqued.

http://www.raskcycle.com/techtip/webdoc14.html

 

[Jer29_11_13]

Yes Bob you are correct I should have called it the "prop adapter"

Thanks to all for your help, I'll probably have more questions as I go.

Hope to be on the Oklawaha this weekend doing some bowfishing 8)