3-Blade Prop

[Paul R. Mitchell]

I'm thinking about switching to a 3-Bladed prop on Dilemma, our '83 H27 w/ 8-hp Yanmar. What is the proper diameter/pitch?Has anyone out there replaced their 2-blade prop-walk special with a 3-blade? Fixed pitch or feathering? How did it work out?Enough questions for now.Thanks,Paul

 

[Henry Weber]

Yanmar side sprint

Paul -- Used to have a 3-blade prop on my H30 with YanmarYSB12. The side walk to the right while reversing was incredible until the boat built sternway. 6 mo. ago I changed back to the 2-blade. It seems to have about the same amount of walk. Perhaps it takes a bit longer for the prop to get a bite on the water when you first shift into reverse. In both cases you need to count on turning about 30 degrees until you get stearage, then back off on the power and it steers well in reverse.Henry

 

[Bill Gander]

PaulI have a H27 with an 8HP SVE8 and changed to a 3 blade 7 04 8 years ago. I don't know the Dia. or Pitch and won't be able to find out until it's hauled in the spring. My mechanic suggested the proper size. I'm very pleased with the results, doesn't seem to give much more drag nor any more speed but it sure does help when heading into strong winds and chop.Prop walk, well you just have to accept it I think.Bill

 

[Howard]

More details please:

I have the same engine on my 78 H-27 and have often wondered if a 3 blade would increase cruising speed under power,if it would increase my ability to head into a chop and what the effect of the load on the small 8hp. Have you noticed an increased load on the motor? How about operating RPM? I too would like to know the size and pitch for your 3 blade if you can find it when you haul for the season.Can you email the data to me: Nelsonhow@netscape.netThanks

 

[Paul Strine]

Three blade prop

I have just replace my old two blade fixed prop with a brand new shinny 3 blade Autoprop and it is excellant in all respects. it is pricey but worth it.

 

[Steve Dion]

No more load on the engine.

A three blade prop is NOT going to produce additional load on the engine. USUALLY you either reduce the pitch by 1-2 deg. when you add a blade. The other option is to reduce the diameter by one inch and add an additional blade.I would only recommend that you have a prop shop calculate the proper prop for your vessel.