3+ blade help

Airboat propeller discussion.
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GAFF SHOT
Southern Airboat Member
Posts: 7
Joined: Thu Aug 08, 2019 10:50 am

3+ blade help

Post by GAFF SHOT » Sun Aug 11, 2019 9:46 pm

Currently have a 500 caddy with a 2:1 reduction, 2 blade water walker. Redline rpm is 4200 and cruise about 3200. If I switch the prop to a 3 or more blade that should help with more power correct? Also what will it do to fuel economy, increase or decrease? Also will it lower cruising rpm? Any advice greatly appreciated, still new to the airboat community. so much to learn.
:old_glory: 13x7 2001 Viking with 500 Caddy :florida:

SWAMPHUNTER45
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Location: Naturecoast, Florida

Re: 3+ blade help

Post by SWAMPHUNTER45 » Mon Aug 12, 2019 6:13 am

Power is made at the engine and multiplied by the drive. More info on the prop would be helpful in looking at your situation. The overall length of the prop, current pitch setting and blade model (width) will help people to offer an informed opinion and provide their advice.

Are you sure it is a true 2:1 ratio ?

If your currently able to turn a 2 blade to 4200 the only way you could successfully add a blade would be to dramatically reduce pitch, diameter or blade width. When running a Cadillac your best resource for information will be Mr. Branch (352)797-9910 he keeps tabs on prop and ratio combinations. Primarily with Sensenich but he has had his customers run Whirlwind and WaterWalker.

If your running that 2 blade prop way over pitched then you would be a candidate for a 3 blade. If your not over pitched then you may be lite on power. One thing a 3 blade may give you is a lower cruise rpm but really I would need to see how the boat ran to offer serious advice.

GAFF SHOT
Southern Airboat Member
Posts: 7
Joined: Thu Aug 08, 2019 10:50 am

Re: 3+ blade help

Post by GAFF SHOT » Mon Aug 12, 2019 7:00 am

Thanks I’ll give branch a buzz.
:old_glory: 13x7 2001 Viking with 500 Caddy :florida:

GAFF SHOT
Southern Airboat Member
Posts: 7
Joined: Thu Aug 08, 2019 10:50 am

Re: 3+ blade help

Post by GAFF SHOT » Mon Aug 12, 2019 7:15 pm

Wow just got off the phone with buddy and that man is mad scientist when it comes to the 500. Couldn’t be happier with the recommendation. Thanks again
:old_glory: 13x7 2001 Viking with 500 Caddy :florida:

SWAMPHUNTER45
Site Supporter - III
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Posts: 2851
Joined: Thu Nov 21, 2013 11:38 am
Location: Naturecoast, Florida

Re: 3+ blade help

Post by SWAMPHUNTER45 » Mon Aug 12, 2019 10:20 pm

I call him the "WIZARD" !

It would be worth the money to have him look your engine over and offer up his opinion if he would have the time to do that anymore.
As of lately he turns down a lot of work because he has a line of people waiting on new engines. If your gonna be a Cadillac power boat it is worth the trip to see his little shop.

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