Four Blade Results

[imstriker]

I took my boat off the water last year with the Mercury 3 blade prop that came from the factory. Over the winter I decided to put a new four blade on. After getting her back in the water, all I can say is wow. Obviously the long winter lay-up makes it hard to make a direct comparison but for my memory it is night and day. It planes out much quicker, seems to trim out easier, and overall just feels quicker. I almost feel like I got a new boat. If it is just placebo effect, I will certainly take it At any rate, just needed a place to share beyond my wife and son who look at me with a weird look when I get all excited about a prop.

 

[Starcraft5834]

Re: Four Blade Results

yep... 4 blades are better than 3 make sure your engine RPM's at WOT are in the recommended range... if you are.. your good to go!

 

[Bullrider]

Re: Four Blade Results

yep... 4 blades are better than 3 make sure your engine RPM's at WOT are in the recommended range... if you are.. your good to go!

After I put on my four bladed prop I was disappointed in the performance, only to find the real issue was needing a tune up, I then rebuilt the carburetor and WOW I love that prop! I can zip around a dime with seven cents change! On plane at a lower RPM. Im happy with my fuel economy too!

 

[eavega]

Re: Four Blade Results

I just recently made the switch from a 20P sst 3-blade to a 17P aluminum Solas Amita 4 blade. I reported my numbers on another thread, but for your reference;

20P 3-Blade SST
WOT= 4200
Top Speed = 38
Hole Shot ~ 5-6 seconds
Min plane speed ~ 13-14 MPH

17P 4-Blade Aluminum
WOT RPM = 4500
Top Speed = 37
Hole Shot ~ 4 sec.
Min plane speed 9 MPH.

Another observation I made was that the four-blade improved low-speed tracking. Other users had commented that switching to a 4-blade tended to keep you from blowing out around corners, but I didn't really notice a change there.

End result is that the 4-blade as now taken position as my everyday prop, with the 20P SST relegated to "spare" duties. I'll see if those numbers hold true when the water warms up, as I have noticed a change in performance with various motors as water warms up on the lake.

Rgds

 

[Starcraft5834]

Re: Four Blade Results

Agreed! as they say.. "it is what it is".. benefits far exceed the one draw back.. loss of about 1mph top end speed. enjoy!

 

[Lager]

Re: Four Blade Results

I just installed a 4 blade on mine also and noticed many good differences. Just makes me wonder why most engine manufacturers install a 3 blade to begin with?

 

[phillnjack2]

Re: Four Blade Results

engines come installed with cheap aluminium props that are basic all round everyday prop.
every engine manufacturer also has a nice range of very good props for different applications.
A very good prop is also very expensive and bumps up the price of the engine by a lot.

now why sell you the engine with a 4 blade stainless steel stearn lifting prop when you really need a bow lifting 3 blade high rake prop
to go very fast ?
and vice versa.
a 4 blade gives more grip in the right type of installation, but can also be the wrong prop for many other types.

for instance the brp renegade bass prop don't work anything like the raker and both these are not like the sst.
all three props can be got in the same diameter and pitch and will all give different results on any particular boat.

so the dealer gives you an "average prop" not a decent prop, just an average get you started prop.


phill

 

[pecheux]

Re: Four Blade Results

Iboat recomends to lower pitch one inch when going from 3 blades to 4 blades prop to get same performance. Nobody here mentioned a drop in pitch ??? Asking since planing make the switch to 4 blades on a small 9.9 hp and was considering a 1 inch pitch drop. Would I expect same positive results as you guys ??

Cheers

 

[imstriker]

Re: Four Blade Results

I cannot speak to your particular case on the 9.9 but I did drop an inch on pitch with mine. It kept me in the right RPM range. Oddly enough I seem to be getting a higher top speed out of mine. Perhaps my old prop was a bit bent.

 

[Lager]

Re: Four Blade Results

Iboat recomends to lower pitch one inch when going from 3 blades to 4 blades prop to get same performance. Nobody here mentioned a drop in pitch ??? Asking since planing make the switch to 4 blades on a small 9.9 hp and was considering a 1 inch pitch drop. Would I expect same positive results as you guys ??

Cheers

Yes. I boats and many others suggest reducing prop pitch to counteract the increased drag the 4 blade has over the 3 blade. I have noticed better accel and better prop bite on hard turns using the 4 blade,many others have also but they are are all on your run of the mill bowriders using mid to low range engines producing 100 or slightly above HP engines trying to push heavy fiberglass hulls. When I owned my high performance engines and hulls, I would have never considered using a 4 blade because all I was interested in was. top speed.Ive also owned a few small boats with small engines like yours and really enjoyed them ( more then then I like larger boats), but I never considered or wanted a 4 blade. So why do you?

 

[bajaunderground]

Re: Four Blade Results

I've recently ordered the Solar Titan HR 14 1/4" x 17P four blade stainless steel prop. Coming off a 14 1/2" x 19P Volvo Penta 3 blade aluminum prop...I can hit 4,100rpms (~40GPS) with current prop with planing happening in about ~10 seconds...hope to increase planing speed and run in the WOT range of 4,200-4,600? Not looking for top end, just off the line pop and ability to get my not-so-small butt up on slalom.

FWIW, the 3 blades are more desirable for top end speeds are they have less resistance...design, rake and diameter all play a part of hitting the sweet spots. 2 blades props (not trolling motor props) are even better for top end (can't say I've ever seen one, but have heard they exist on some older school go-fast boats!?) And by theory a 1 blade prop would be even faster...alas, the vibration at any speed would destroy just about everything?!

 

[5280glastron]

Re: Four Blade Results

I've recently ordered the Solar Titan HR 14 1/4" x 17P four blade stainless steel prop. Coming off a 14 1/2" x 19P Volvo Penta 3 blade aluminum prop...I can hit 4,100rpms (~40GPS) with current prop with planing happening in about ~10 seconds...hope to increase planing speed and run in the WOT range of 4,200-4,600? Not looking for top end, just off the line pop and ability to get my not-so-small butt up on slalom.

Similar results to my swap from a 19" aluminum 3 blade to a 15" 4 blade Titan. I'm at altitude and still managed 40 MPH with the volvo 5.0 gl on our 195sx. Oddly I'm still trying to figure out my max RPM as we suspect the 4400-4500 the tach reads is impossible.

 

[rickyvols68]

Re: Four Blade Results

Ordered the Solas Titan 4 blade 18p from Iboats, had a 3 blade 21p, its like a brand new boat, planes out immediately.

4.3 mercruiser

 

[Sea Rider]

Re: Four Blade Results

Planing make the switch to 4 blades on a small 9.9 hp

Standard factory delivered props usually achieves near or max wot rpm factory stated for a particular engine, provided that engine works on light applications. What's your current boat size and max rated HP engine ? Before replacing original prop will need to determine your current wot numbers with you alone and lightly loaded boat and that's with an induction tach installed. No guessing on this one, if under or over reving could pick a 4 blade prop that puts engine to rev near max rpm for engine to run safely at wot.

Happy Boating

 

[pecheux]

Re: Four Blade Results

Yes. I boats and many others suggest reducing prop pitch to counteract the increased drag the 4 blade has over the 3 blade. I have noticed better accel and better prop bite on hard turns using the 4 blade,many others have also but they are are all on your run of the mill bowriders using mid to low range engines producing 100 or slightly above HP engines trying to push heavy fiberglass hulls. When I owned my high performance engines and hulls, I would have never considered using a 4 blade because all I was interested in was. top speed.Ive also owned a few small boats with small engines like yours and really enjoyed them ( more then then I like larger boats), but I never considered or wanted a 4 blade. So why do you?

Need a new prop to replace dented one. (that I would keep as spare) Read from Iboat that a 4 blades (minus 1 inch pitch) provided better hole shot and less vibration Trying to figure out from feedback is this has any positive results on a small 9.9 hp Johnson OB mounted on a 14 footer fiberglass boat. (as per avatar) Installed an Hydrofoil and gained performance in hole shot and lower speed plane. I would go 4 blades prop for any additional gain. (yes love this motor, loll)
thank you.

 

[Lager]

Re: Four Blade Results

Need a new prop to replace dented one. (that I would keep as spare) Read from Iboat that a 4 blades (minus 1 inch pitch) provided better hole shot and less vibration Trying to figure out from feedback is this has any positive results on a small 9.9 hp Johnson OB mounted on a 14 footer fiberglass boat. (as per avatar) Installed an Hydrofoil and gained performance in hole shot and lower speed plane. I would go 4 blades prop for any additional gain. (yes love this motor, loll)
thank you.

I see that you are not new boating, you have had larger boats and just like your small boat. Im with you on that one. I know some folks say that you have to watch your RPMs and select a prop from there. But, thats really going to be hard to do on a 10 hp kicker motor.If you really want to try the 4 blade, I would order what you think will fit and give it try. You know what your motor already sounds like and gauge rpm with the new blade accordingly.I haven't checked, but Im betting props that size dont cost a lot in alum. So buy a stock 3 blade and the different pitch 4 blade and let us know how they work?

 

[pecheux]

Re: Four Blade Results



I see that you are not new boating, you have had larger boats and just like your small boat. Im with you on that one. I know some folks say that you have to watch your RPMs and select a prop from there. But, thats really going to be hard to do on a 10 hp kicker motor.If you really want to try the 4 blade, I would order what you think will fit and give it try. You know what your motor already sounds like and gauge rpm with the new blade accordingly.I haven't checked, but Im betting props that size dont cost a lot in alum. So buy a stock 3 blade and the different pitch 4 blade and let us know how they work?

In a perfect world that would be the best option. But in my neck of the wood that means $ 200. of un-refundable money. Tx