Prop choices

[TC tonnage surveyor]

My Bayliner 2452 Hard Top takes a long time to plane, even with a add-on trim device. The engine is a 305 Merc I/O . I would like to try a 4 blade prop of similar pitch to get 'out bof the hole' quicker yet remain with the same or better fuel consumption.
Have anyone on this list had experience with the 3 vs 4 blade prop change? and if so what were your conclusions?
Thanks

 

[Bamaman1]

Re: Prop choices

Chances are you may have a propeller with too much pitch. Pitch is like changing gear ratios on cars.

Are you running the engine's redline at full throttle when it's trimmed out?

I have found that hydraulic trim tabs are the best way to get more pulling power. They're just fantastic, and not too expensive @ $400 ish. And, anyone can install them. They're available online and at major marine suppliers.

 

[jestor68]

Re: Prop choices

We need more info to make any kind of informed recommendations.

Cruisers in your size range usually have 5-6 second time to plane. That is slow compared to your average family boat( around 3 seconds). A prop change could improve things; but first we need to know what is on there now and the WOT rpm the motor is getting as well as speed.

I have an idea of what should be on there, but I will wait to see what you have.

 

[steelespike]

Re: Prop choices

A description of your hole shot would also help. some might consider a hole shot measured in seconds slow others that measured in minutes.
A 4 blade prop could improve hole shot and mpg.
also might seem smoother and have more responsive handling
But top speed may be reduced.

 

[TC tonnage surveyor]

Re: Prop choices

We need more info to make any kind of informed recommendations.

Cruisers in your size range usually have 5-6 second time to plane. That is slow compared to your average family boat( around 3 seconds). A prop change could improve things; but first we need to know what is on there now and the WOT rpm the motor is getting as well as speed.

I have an idea of what should be on there, but I will wait to see what you have.

15 x 17P 3 blade with trim tabs. WOT 4600 rpm @ 40mph. I have owned many boats but thought this to be a bit sluggish. Bayliners have been notoriously underpowered to keep the base price down and it 'may' be that the Merc 350 CI would have been a better choice engine. A 'silk purse out od a sow's ear' may be my plight.
I asked the Merc mechanic, when he tested the boat after the I/O hose 'package' replacement, about it and he confirmed the slower time to plane but said that the rpm and top speed were about right. However, he said that the cost of the 4 blade would be a net loss unless I owned the boat for 5 more years -lol-
Thanks for your replies. The change to the 4 blade results are what I was really interested in, as I have never used one of these before. Recommended make and model? cost??

 

[jestor68]

Re: Prop choices

Since you're running good rpm now, and looking to improve the hole shot, I would recommend trying a Quicksilver 16 X 16 3 blade aluminum prop to generate more static thrust to get you up on plane faster. You're trading diameter for pitch, so that prop should run close to the same WOT rpm.

That prop is expressly made for cruisers in your weight category. At $150, it won't break the bank.

Michigan makes a 15 X 16 4 blade aluminum prop that should also provide improved acceleration for your application in the same price range.

 

[TC tonnage surveyor]

Re: Prop choices

Since you're running good rpm now, and looking to improve the hole shot, I would recommend trying a Quicksilver 16 X 16 3 blade aluminum prop to generate more static thrust to get you up on plane faster. You're trading diameter for pitch, so that prop should run close to the same WOT rpm.

That prop is expressly made for cruisers in your weight category. At $150, it won't break the bank.

Michigan makes a 15 X 16 4 blade aluminum prop that should also provide improved acceleration for your application in the same price range.

Thanks Jestor68! That was exactly what I was looking for. Now, has anyone on this forum made the change to a 4 blade over their 3 blade with a similar size boat. I have several up here that have boasted of the improved performance of their boats, but they were much smaller vessels.
TC tonnage surveyor