Thinking of changing to 4-Blade

[Zeusdafreak1]

I have a Tahoe Q4 Sport 19.5 ft with a 4.3 Mercruiser Sterndrive 190 HP. I currently have a 14.5 x 23P 3-blade aluminum on the boat and it got chewed a bit yesterday(hit concrete landing didn't trim up enough on shallow landing). Anyway I have a brand new second prop in the box but its a 14.5 x 19P. I was happy with the performance of the 23P though and was thinking of buying another prop and leaving the Black Max 19P new and selling it without trying it because I am afraid the dramatic drop in pitch will not perform as well unless someone has a guess at this one.

With the 14.5x23P aluminum I run WOT at 5000RPM(range for my motor is 4400-4800) with a load and top speed hits about 53-54MPH. I was thinking of buying a 14 x 23P SS 4-blade. I know by reading that the extra blade should drop my WOT 100-200 and the SS may drop it 100-200 as well but I don't want to wind up going from 5000RPM all the way down to 4500 WOT. This may defeat the purpose. Any thoughts how this 14x23 4-blade SS may react in comparison to my current setup with the 14.5x23 3-blade aluminum?

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

I tried the 14.5x19 today with interesting results. The hole shot was stronger, planing was quicker and more prominent, but top end suffered dramatically. It dropped from 54 with the 23 pitch to 46 with the 19 pitch. The rev limiter was going crazy at WOT as well. I had it trimmed all the way down and the RPMs keep topping at 5000 and dropping to 4500 like crazy, almost like it was cavitating. Could this be a rev limiting feature?

Anyway. I didn't like the performance of the 14.5 x 19 AT ALL. I didn't have a problem with the performance of the hole shot with the 23 pitch. I went ahead and bought the 4 blade SS Solas HR Titan 14x23. I hope it does a better job. I will sell this Black Max 14.5 x 19 to offset the cost of the $175 I spent on the 4 blade stainless. Still waiting for the prop gurus to come in from boating and give me some opinions on how the 4 blade MAY perform.

 

[JUSTINTIME]

Re: Thinking of changing to 4-Blade

stick with the 23 pitch

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

OK. To summarize the situation:
Could someone speculate the difference in performance between

Black Max Alum 14x23P 3 blade
vs.
Solas HR Titan SS 14x23P 4 blade

The black Max hit 5000RPM(range should 4400-4800) and 54MPH and performed nice.(See above post for all the performance numbers)

What would you presume changing to SS and adding and extra blade would do? Keep in mind this Titan prop is a high rake design. Will WOT RPMs go up, down, same? What about top speed?

Literature about the HR Titan 4 "claims" excellent cruising performance. In addition to its high rake and large cupping design, the 4 blade design can deliver not only a very powerful thrust but also smooth operation offering excellent cruising performance and maneuvering capability.

 

[JUSTINTIME]

Re: Thinking of changing to 4-Blade

4 blade better hole shoot and cruising speed
probably will keep the bow down also

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

Ttt

 

[tmh]

Re: Thinking of changing to 4-Blade

The 4-blade SS should do just what you want - better hole shot, lower planing speed and I doubt you'll lose a thing on top end, maybe gain because SS has less "give" than aluminum.

WOT RPM may drop some, but into proper range not 4500.

I predict you'll be very happy with the new prop. The 19" should have just been sold new, as it was way to little prop if your 23" was already at the top of the WOT RPM range.

Report back how the new prop does for you!

 

[Tail_Gunner]

Re: Thinking of changing to 4-Blade

I have a Tahoe Q4 Sport 19.5 ft with a 4.3 Mercruiser Sterndrive 190 HP. I currently have a 14.5 x 23P 3-blade aluminum on the boat and it got chewed a bit yesterday(hit concrete landing didn't trim up enough on shallow landing). Anyway I have a brand new second prop in the box but its a 14.5 x 19P. I was happy with the performance of the 23P though and was thinking of buying another prop and leaving the Black Max 19P new and selling it without trying it because I am afraid the dramatic drop in pitch will not perform as well unless someone has a guess at this one.

With the 14.5x23P aluminum I run WOT at 5000RPM(range for my motor is 4400-4800) with a load and top speed hits about 53-54MPH. I was thinking of buying a 14 x 23P SS 4-blade. I know by reading that the extra blade should drop my WOT 100-200 and the SS may drop it 100-200 as well but I don't want to wind up going from 5000RPM all the way down to 4500 WOT. This may defeat the purpose. Any thoughts how this 14x23 4-blade SS may react in comparison to my current setup with the 14.5x23 3-blade aluminum?

Here's a little experience i learned going to ss = 1-200 rpm loss (1 pitch) adding a 4 blade 1-200 rpm (1 pitch) adding a some cup and rake (1 pitch) That would put you in a 20-21 pitch high quality ss 4 blade.

Probable result's loss of 1-2 mph, smoother operation, more midrange punch somewhat better hole shot and better fuel economy, now the fuel econ should come from a prop that has a lot of stern lift raising your hull out of the water reducing drag catching some air and light'n the boat a bit.....But your mileage may vary and a lot...........


Opp's one question, do you have a rev limiter in your boat and have you checked your tach to within 50-100 rpm??

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

Sounds like I may have picked a winner OR maybe I may need to drop an inch or two. I bought the 4 blade SS 14x23p and its on the way. I also bout a replacement 3 blade alum 14x23p today too. At least I know what the performance will be with that one and hopefullt will stand as my backup prop.

I can always sell the 4 blade SS if it doesn't perform as well and buy another to test.

I have read that the 4.3 Mercruiser comes standard with a rev limiter but I do not know at what RPM. How do I verify my Tach to within 50-100RPM?

Also what do you mean" but your mileage may vary and a lot"?

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

Just got my new Solas HR Titan 14x23 4-Blade in today. This thing is awesome! If it performs as good as it looks I will be pleased. I just wanted to hold it for while before I put it on. LOL.

I will be testing this bad boy out tomorrow. Wish me luck!

 

[tmh]

Re: Thinking of changing to 4-Blade

Based on your info, i'll bet it performs great. let us know.

 

[swtch7]

Re: Thinking of changing to 4-Blade

Just got my new Solas HR Titan 14x23 4-Blade in today. This thing is awesome! If it performs as good as it looks I will be pleased. I just wanted to hold it for while before I put it on. LOL.

I will be testing this bad boy out tomorrow. Wish me luck!

i cant wait to find out how this preformed! i have a 19ft maxum bowrider with a 4.3 merc cruiser and have the wrong prop. I have a 5 blade 21p that loves to cavitate, and the hole shot pretty much stinks aswell. Max rpm is around 5000 but im only hitting maybe 43-45. I may have to try out this 4 blade prop!

GOOD LUCK!
-Ernie

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

I will definitely post the results from today. Are you sure it is cavitation or is it hitting the rev limiter?

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

Well. I got a full day with the new 4 blade SS 14x23 and let me tell you. Very different performance from the SS 3 blade. Results are as follows:

Hole shot - not quite as good
mid-throttle punch - much more
Top end - faster @ 55 MPH

Now with the old alum 23p 3-blade I had a top speed of 53 @ 5000 RPM
This new SS 4blade 23p has a top speed of 55 @ 4200 RPM
Thats a drop of 800 RPM adding a blade and going SS! the good thing is I bet I didn't burn nearly as much gas today.

Handling was much smoother, held the water better, turned better, took the wake better, virtually everything was much better except hole shot. I had 4 adults and one child in the boat pulling a big bertha tube with 2 110lb kids and it seemed to struggle a bit to get on plane. I have never had a problem with planing before but that was a lot of weight in the boat.

This prop also had much better bow rise or stern rise( it enabled me to trim out of the water much higher hence the higher top speed). I pulled the boat so far out of the water I got scared to go any further to get it to the point of ventilating. It was up as high as it needed to be at that point without going any further. It was already starting to get a little uneasy at that height.

I am pleased with the handling and top end. Hole shot may not be a problem. I didn't notice a problem with just the normal group in the boat and nothing being pulled. It was only pulling that I noticed a lag in planing. I am supposed to be at 4400-4800 WOT and I am now at 4200 with this prop. If I were to try one more prop it would definitely be SS and 4-blade. I'm thinking 22p or 21p. Any thoughts after getting multiple data on these different props on my setup?

 

[studlymandingo]

Re: Thinking of changing to 4-Blade

Is the new prop vented?

If not, doing so could help your holeshot considerably.

If your max RPM is 4200 though, you could be overpropped.​

 

[swtch7]

Re: Thinking of changing to 4-Blade

Well. I got a full day with the new 4 blade SS 14x23 and let me tell you. Very different performance from the SS 3 blade. Results are as follows:

Hole shot - not quite as good
mid-throttle punch - much more
Top end - faster @ 55 MPH

Now with the old alum 23p 3-blade I had a top speed of 53 @ 5000 RPM
This new SS 4blade 23p has a top speed of 55 @ 4200 RPM
Thats a drop of 800 RPM adding a blade and going SS! the good thing is I bet I didn't burn nearly as much gas today.

Handling was much smoother, held the water better, turned better, took the wake better, virtually everything was much better except hole shot. I had 4 adults and one child in the boat pulling a big bertha tube with 2 110lb kids and it seemed to struggle a bit to get on plane. I have never had a problem with planing before but that was a lot of weight in the boat.

This prop also had much better bow rise or stern rise( it enabled me to trim out of the water much higher hence the higher top speed). I pulled the boat so far out of the water I got scared to go any further to get it to the point of ventilating. It was up as high as it needed to be at that point without going any further. It was already starting to get a little uneasy at that height.

I am pleased with the handling and top end. Hole shot may not be a problem. I didn't notice a problem with just the normal group in the boat and nothing being pulled. It was only pulling that I noticed a lag in planing. I am supposed to be at 4400-4800 WOT and I am now at 4200 with this prop. If I were to try one more prop it would definitely be SS and 4-blade. I'm thinking 22p or 21p. Any thoughts after getting multiple data on these different props on my setup?

Nice results!

I took my boat out again last night and went over a few things. with my 21p 5 blade at WOT I was around 5200 RPM at 42mph (5 adults 1 child in the boat). I think im going to look around for a 4 blade 22p if they make them. whole shot isn?t really an issue as we were pulling a tube and didn?t have a problem. The only time I have cavitation issues is when you are at a dead stop and punch it, although I have no reason to do it im just wondering if that cavitation issue is affecting anything else.

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

I realized after I posted last night why my hole shot was fine at first but struggled later in the day. It was because I was pulling those 2 110lb kids on the tube upstream! We were in the Mississippi river and we went around an inlet "oxbow" section that was smooth but has considerable current. This, along with 4 adults and one child in the boat and a huge big bertha plowing with 2 big kids on it will have a considerable impact on hole shot. DUH!!!!!

OK. On the 4200RPM WOT. My suggested range is 4400-4800.
If I run this prop and call it quits on the testing do I risk damaging my boat due to overstress? Is 4200 seriously lugging or am I close enough? Also is this enough under on RPMs to see a dramatic impact on fuel mileage?

I really liked the performance of this prop. Should I try a 22p or 21p or even a 19p. I would most definitely go with this exact same 4blade high rake deal. If I were to get one I would really like to troll fleebay for a while and maybe wait on one since I can't seem to easily find one at a reasonable price online. I assume the different prop with the 22p thru 19p would be increased RPM hopefully into upper end of range, slightly better hole shot, and a decrease of 2-3 MPH per inch on top end. If the 4200RPM would cause a problem by overstressing the engine I would like to like to know now before I move on to other things and forget about it.

which prop pitch will get me closest to 4800-4900 without hitting 5000?

 

[athiker]

Re: Thinking of changing to 4-Blade

I've read that overpropping may not be too good for your engine, but don't know that to be true. From reading the posts above I would tend to agree w/ Tail Gunner and think that the 21p version of your new 4 blade SS should put you right in your sweet spot. You may give up a tad on the top but really improve your holeshot. I would much rather have a nice hole shot and give up a few mph top than vice versa...plus the added bonus of no worries about lugging and being overpropped. It'll be more fun than weighing your passengers and moving the heavy ones to the bow!

I don't know how much going to a 22p is going to change things, besides you have 600 rpms of room to play with. With a 4.3L I would think you need to spin some rpms to get into your optimal torque range. The other issue is can you get a version of your new prop in 22p or would you need to go to a different brand w/ a different shape? That would introduce some new variables. It sounds like you like the new prop, you just need to go down a couple pitches. My 2c. Please post back if you do switch...any chance of an exchange w/ Solas?

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

I ordered the exact prop in a 21 pitch today at lunch. Solas didn't offer the exact high-raked cupped prop in a 22 anyway. My choices were 21 or 19. If you stick to the 200RPM per inch of pitch then I should go from 4200 to approx 4600, hopefully slightly more if I am lucky.

The 19 would have possibly put me too far to the max at 5000+. I didn't want to chance it. These darn props are very expensive! I went with the 21 pitch.

No, there is no chance of exchange from the first prop because I bought it new from an individual. Its still in brand new condition so I will most likely just sell it on Fleebay. I also have a Black Max NIB 14 1/2 x 19 aluminum that came with the boat that I will also sell to help offset the cost of this new one ordered today. after the huge difference the 4 blade made this past weekend over the 3 blade aluminum I don't have a problem dropping the money. It was 100% worth it. It was like driving a totally different boat. Even the family could tell the difference in the ride, handling, and overall performance, now to take care of this minor lugging problem. I wonder what I should expect going from this 23p to the 21p considering the cupped, high rake design?

 

[Zeusdafreak1]

Re: Thinking of changing to 4-Blade

Here's a little experience i learned going to ss = 1-200 rpm loss (1 pitch) adding a 4 blade 1-200 rpm (1 pitch) adding a some cup and rake (1 pitch) That would put you in a 20-21 pitch high quality ss 4 blade.

Probable result's loss of 1-2 mph, smoother operation, more midrange punch somewhat better hole shot and better fuel economy, now the fuel econ should come from a prop that has a lot of stern lift raising your hull out of the water reducing drag catching some air and light'n the boat a bit.....But your mileage may vary and a lot...........


Opp's one question, do you have a rev limiter in your boat and have you checked your tach to within 50-100 rpm??

Tailgunner, It looks like you were right on the prop choice. I ordered a 21p today! One thing though, the 23p actually went 3 mph faster but once I get the 21p on it may slow a bit. Dropping 2 inches in pitch but going up 400RPMs. Hope it performs on par with the other one.