4 blade prop v 3 blade prop

[blue fin]

I was wondering if anyone out there has switched to a 4 blade prop from a 3 blade and what diference did it make..( I am trying to get up on the plane with less revs and want to get my nose down a little more)..

I have a 5.8 fisher with a 150 yammy 4 stroke (3 blade ally prop) on the back, i have recently put a foil on it and it has made a big difference to getting onto the plane quicker, but i want a little bit more. will the 4 blade give me what i am trying to achieve??

any feed back would be appreciated..

thanks..

[FNQCairns]

yes it will assuming it is a well setup 4 blade choice, it will also allow you to raise the engine higher than a typical 3 blade and get that fin out of the water at lower speeds.

But lots of dancing around actively working to decrease overall efficiency when a set of say Volvo trim tabs would literally pay for themselves in short time by comparison.

cheers fnq

cheersfnq

[trueblue]

4 blade props do have to be perfectly tuned to the boat. and seeing as most prop choices come in 2" pitch increments, its pretty hard to get one just right for your boat.

they do have dome good advantages.

Heavy boats will be pushed better
following and surging seas will be easier to drive in because of better grip, and you will be on and off the throttle less
better grip for boats that tend to ventilate
does lift the stern out of the water more than most 3 blade props
good low speed planing capabilities
can be run higher on the transom than most 3 blade props, especially yamaha cleaver style props

but, you usually sacrifice something - and if it is not perfectly set up, it will probably cost you fuel economy

[Fed]

Four blade propellers usually:

Plane the boat faster than 3-blade propellers
Keep the boat on plane at a lower speed
Give improved mid-range speed at the same RPM as a 3-blade propeller
Provide quicker acceleration than most 3-blade propellers
Run smoother than 3-blade propellers
Have better holding power in rough conditions
Are less likely to ventilate in sharp turns
Provide better low speed handling
Are not quite as fast on the top end as a comparable 3-blade propeller
If you’re upgrading from a three blade to a four blade propeller, remember that a four blade propeller generally turns 50 to 100 RPM less than a three blade prop with the same pitch.
http://sites.mercurymarine.com/portal/page?_pageid=126,49901,126_49907&_dad=portal&_schema=portal

[FNQCairns]

Four blade propellers usually:
Plane the boat faster than 3-blade propellers
Keep the boat on plane at a lower speed
Give improved mid-range speed at the same RPM as a 3-blade propeller
Provide quicker acceleration than most 3-blade propellers
Run smoother than 3-blade propellers
Have better holding power in rough conditions
Are less likely to ventilate in sharp turns
Provide better low speed handling
Are not quite as fast on the top end as a comparable 3-blade propeller
If you’re upgrading from a three blade to a four blade propeller, remember that a four blade propeller generally turns 50 to 100 RPM less than a three blade prop with the same pitch.
http://sites.mercurymarine.com/portal/page?_pageid=126,49901,126_49907&_dad=portal&_schema=portal

Yes all of the above is true, trouble is so will a big elephant eared low performance (high surface area to pitch ratio) 3 blade prop do all of the above and bit better by a bit again, except the smoothness.

Except it's far easier to sell a spiffy blade shaped 4 blade than a doughy looking 3 blade.

cheers fnq

[Fatenhappy]

Hey Blue Fin ...

From personal experience, give Steve and the boys at Solas a call.

They know their stuff, are extremely helpful and give advice with nothing seeming to be too much trouble.

Greg

[Fed]

The angle of the motor when it's fully trimmed in is something that should be considered too, not all transom angles & motors are created equally.

[Red60]

G'day bluefin.

I have a Tabs 435 Territory with a Merc 60 EFI. It is bum heavy specially with me at the back. I also had slow to plane and nose high attitude. A Permatrim made a huge difference, lifting the engine higher also helped. It was still a little gutless out of the hole. I switched from a 3 blade black max 13p prop to a 4 blade Trophy Sport stainless in 12p. It did make a big difference. It accelerates much harder, is quicker to plane, holds the plane much easier and I have not lost any top speed as the previous prop was over pitch for my boat so I never got max revs. I am very happy with my four blader. Got the 3 blader for emergencies but its never going back on!