Going from 3 blade to 4 blade

[98Shabah]

I recently bought a 21' Caravelle with the VP 5.0GXi, it had the factory 21p 3 blade 14.25" aluminum prop (in like new condition), with two adults, full of fuel, and a beach gear it would hit 54mph at just 4,600rpm (WOT for this engine is 3600-5000), it was slow to get on plane, and with a boat full of teens it was horrible to maintain speed with a wakeboarder behind it. I went with the Solas Amita 4 blade (no hub kit required) aluminum 14.3" in a 19p, with the same load as before it now does 53mph at 5,000rpm, hops up on plane almost immediately, and stays on plane down to 19-20mph. I've yet to pull a wakeboarder or load the boat down but this is a night and day difference. My cruise speed at 3,000rpm is 31mph, at 3500rpm it's 38mph. If I punch it wide open from 30mph it actually tosses you back in your seat and accelerates so quickly all I can do is grin from ear to ear. The other bonuses are that it's easier to maneuver around docks with the extra blade, and you don't feel the pulsing like the 3 blade. This is the best $120 I've ever spent.


Oh, and just an extra tidbit, I read that the "Volvo Penta" aluminum props that come on the SX drives are actually cast by Solas.

 

[gapple12]

.........2 or 4 barrell

Alum or SS for prop material...cost is alway's a key...The gearing on your leg is it 1.66????...Do you run on a small lake or large body of water, high speed burst's just for a thrill....Reading your post it seem's your looking for a prop that will enhance the boat with a full passenger load

2 barrel carb. I want to go with aluminum props since my lake is low right now. The lake is fairly large, can take a good 30 minutes from end toi end running 40 to cross. I typical haul at least 4 to 6 people at a time.

 

[gapple12]

I recently bought a 21' Caravelle with the VP 5.0GXi, it had the factory 21p 3 blade 14.25" aluminum prop (in like new condition), with two adults, full of fuel, and a beach gear it would hit 54mph at just 4,600rpm (WOT for this engine is 3600-5000), it was slow to get on plane, and with a boat full of teens it was horrible to maintain speed with a wakeboarder behind it. I went with the Solas Amita 4 blade (no hub kit required) aluminum 14.3" in a 19p, with the same load as before it now does 53mph at 5,000rpm, hops up on plane almost immediately, and stays on plane down to 19-20mph. I've yet to pull a wakeboarder or load the boat down but this is a night and day difference. My cruise speed at 3,000rpm is 31mph, at 3500rpm it's 38mph. If I punch it wide open from 30mph it actually tosses you back in your seat and accelerates so quickly all I can do is grin from ear to ear. The other bonuses are that it's easier to maneuver around docks with the extra blade, and you don't feel the pulsing like the 3 blade. This is the best $120 I've ever spent.


Oh, and just an extra tidbit, I read that the "Volvo Penta" aluminum props that come on the SX drives are actually cast by Solas.

Excellent post, great info !

 

[Starcraft5834]

I too run a Solas 14x15 4blade... solas makes a nice product

 

[Tail_Gunner]

Thanks for the reply's everyone. I was out this weekend and with 5 adults in my 19' Monterey, I was at about 4200 RPM and 45mph top speed. I'm sure if i trimmed up the motor I could gain more. Running the 14.25x21 3 blade now, I'm thinking of going to the 14x20 4 blade.

Then this would be a reference point....21p@4200....20p@4400..19@4600...18@4800.. bingo

Then 21p@4200@45mph nets 10% slip, Impressive with a boat load of people....di you use gps to get that reading..and is your final gearing 1.66 or 1.5 something

Drop to a 18 using the same performance....18p@4800 with 9% slip nets 45mph but your hole shot would be crisp and your midrange responsive..and dead on with rpm to wot.

This all assuming you have a 1.66 gearing ratio and used gps for speed. Solas makes a fine 4 blade alum...yep 4 blade that may even improve the slip a tad... Well shizzle i gues they dont make a 18p 4 blade alum...and the numbers look good for a 19 at 4600

 

[gapple12]

Then this would be a reference point....21p@4200....20p@4400..19@4600...18@4800.. bingo

Then 21p@4200@45mph nets 10% slip, Impressive with a boat load of people....di you use gps to get that reading..and is your final gearing 1.66 or 1.5 something

Drop to a 18 using the same performance....18p@4800 with 9% slip nets 45mph but your hole shot would be crisp and your midrange responsive..and dead on with rpm to wot.

This all assuming you have a 1.66 gearing ratio and used gps for speed. Solas makes a fine 4 blade alum...yep 4 blade that may even improve the slip a tad... Well shizzle i gues they dont make a 18p 4 blade alum...and the numbers look good for a 19 at 4600

I used the Motion X gps on my phone to check it. Not sure how to figure out what gearing Im running. Would this be in my Volvo Penta manual ? Im going to be ordering the Solas 4 blade 14x19 end of this week. I will post my numbers once i test it.

Im still trying to understand the pros and cons of having the removable hub on these props. I would think a solid hub/prop would be stronger ?

 

[gapple12]

Well, tested out my new Solas 14x19 4 blade yesterday. Absolutly loved it. Hole shot was half the time and I only lost a few mph top end. When trimming the motor up for top speed, I was about 4700 RPM and 47 mph. This was with about half tank of gas and 5 adults. Real happy !!! Thanks for everyone input.