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anyone know anything about prop pitch?

Posted By: GKelly

anyone know anything about prop pitch? - 02/18/19 09:11 PM

I just got a new to me lowe stinger 175 with a 60hp mercury 4 stroke it has a 10.625x12 pitch 3 blade blackmax prop on it. The motor is rated for WOT rpm of 5500-6000 but it runs close to 6200 rpm now and about 34mph. I'm thinking I need to go up to a 13 or possibly 14 pitch to bring the rpm down some but dont want to lengthen my holeshot. I'm thinking of going with a 4 blade spitfire with a 10.3x13 pitch. 4 blades is supposed to add hole shot performance and I'm hoping the extra inch of pitch will bring my Rpms down below 6000 at WOT without costing me much speed. any ideas?
Posted By: perchjerker

Re: anyone know anything about prop pitch? - 02/18/19 09:32 PM

A four is the very best way to get performance. Lift at lower speeds, better hole shot. In rough water a 3 blade can lose it's bite, a 4 won't.
Posted By: GKelly

Re: anyone know anything about prop pitch? - 02/18/19 09:46 PM

would going from a 3 blade 10.6x12 to a 4 blade 10.3x13 lower my WOT rpm? I'm wondering if the smaller diameter might offset the pitch difference?
Posted By: Hevishot13

Re: anyone know anything about prop pitch? - 02/19/19 04:50 AM

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Posted By: rulebreaker

Re: anyone know anything about prop pitch? - 02/19/19 03:56 PM

Originally Posted by Hevishot13
Several general rules with props:

1: if going from an aluminum to a stainless prop, always drop down one pitch given that everything else stays the same (ie. the same boat, engine, load, prop style, prop brand). Stainless props are heavier thus harder to turn than a lightweight aluminum.

2. A 4 blade prop with have better load carrying tendencies (to an extent) than a 3 blade, but will also be slower (there’s a few exceptions) than a 3 blade. More wheel to spin, therefor more drag in the water. Pitch and diameter will effect both 3 and 4 blade props differently

3. A 4 blade with have more bite than a 3 blade, but will also cause the boat to be harder to maneuver than a 3 blade ( with a few exceptions)

4. Changing 1 pitch size with change the engines Rpms an average of 150 give or take.

5. No two props are alike. This 23 tempest and that 23 tempest will not run the same nor will they have the same tendencies on the same application. Mercury’s stainless props are machine ground on the trailing edge where as Yamaha’s are done by Mexicans. Ymmv


I know that you are in the business an supposed to know what you are saying, but my experience has always been that for example a 21PSS vs. 21alum. the SS prop will out perform on both ends of the spectrum, holeshot and top end speed due to the flex of the alum. prop. That being said, if you are switching to SS from alum. then you can always go up one pitch, not down.
Also, every single time that I have tried a four blade, it was like I had added super easy power steering to the boat, not harder to maneuver at all, much easier. That's been my 40+ yrs of experience anyways.
Posted By: James

Re: anyone know anything about prop pitch? - 02/19/19 04:15 PM

I prefer dropping 2 when going from aluminum to stainless.
Posted By: Hevishot13

Re: anyone know anything about prop pitch? - 02/19/19 06:52 PM

Originally Posted by rulebreaker
Originally Posted by Hevishot13
Several general rules with props:

1: if going from an aluminum to a stainless prop, always drop down one pitch given that everything else stays the same (ie. the same boat, engine, load, prop style, prop brand). Stainless props are heavier thus harder to turn than a lightweight aluminum.

2. A 4 blade prop with have better load carrying tendencies (to an extent) than a 3 blade, but will also be slower (there’s a few exceptions) than a 3 blade. More wheel to spin, therefor more drag in the water. Pitch and diameter will effect both 3 and 4 blade props differently

3. A 4 blade with have more bite than a 3 blade, but will also cause the boat to be harder to maneuver than a 3 blade ( with a few exceptions)

4. Changing 1 pitch size with change the engines Rpms an average of 150 give or take.

5. No two props are alike. This 23 tempest and that 23 tempest will not run the same nor will they have the same tendencies on the same application. Mercury’s stainless props are machine ground on the trailing edge where as Yamaha’s are done by Mexicans. Ymmv


I know that you are in the business an supposed to know what you are saying, but my experience has always been that for example a 21PSS vs. 21alum. the SS prop will out perform on both ends of the spectrum, holeshot and top end speed due to the flex of the alum. prop. That being said, if you are switching to SS from alum. then you can always go up one pitch, not down.
Also, every single time that I have tried a four blade, it was like I had added super easy power steering to the boat, not harder to maneuver at all, much easier. That's been my 40+ yrs of experience anyways.


man I swear, I’m done commenting on the fishing forum. Good luck to yall
Posted By: Rooster600

Re: anyone know anything about prop pitch? - 02/19/19 07:40 PM

Just my opinion, but you’re talking about a 60hp motor not a 300. It’s not a high performance boat we are talking about, it’s just a small fishing boat where a lengthened holeshot or 4 mph slower isn’t going to make a difference. Get your rpm lower and just enjoy fishing.
Posted By: abolt300

Re: anyone know anything about prop pitch? - 02/19/19 09:26 PM

Originally Posted by Hevishot13
Originally Posted by rulebreaker
Originally Posted by Hevishot13
Several general rules with props:

1: if going from an aluminum to a stainless prop, always drop down one pitch given that everything else stays the same (ie. the same boat, engine, load, prop style, prop brand). Stainless props are heavier thus harder to turn than a lightweight aluminum.

2. A 4 blade prop with have better load carrying tendencies (to an extent) than a 3 blade, but will also be slower (there’s a few exceptions) than a 3 blade. More wheel to spin, therefor more drag in the water. Pitch and diameter will effect both 3 and 4 blade props differently

3. A 4 blade with have more bite than a 3 blade, but will also cause the boat to be harder to maneuver than a 3 blade ( with a few exceptions)

4. Changing 1 pitch size with change the engines Rpms an average of 150 give or take.

5. No two props are alike. This 23 tempest and that 23 tempest will not run the same nor will they have the same tendencies on the same application. Mercury’s stainless props are machine ground on the trailing edge where as Yamaha’s are done by Mexicans. Ymmv


I know that you are in the business an supposed to know what you are saying, but my experience has always been that for example a 21PSS vs. 21alum. the SS prop will out perform on both ends of the spectrum, holeshot and top end speed due to the flex of the alum. prop. That being said, if you are switching to SS from alum. then you can always go up one pitch, not down.
Also, every single time that I have tried a four blade, it was like I had added super easy power steering to the boat, not harder to maneuver at all, much easier. That's been my 40+ yrs of experience anyways.


man I swear, I’m done commenting on the fishing forum. Good luck to yall


Dont worry heavyshot, very solid advice and dead on the money. His screen name is Rulebreaker because evidently his boats break all the rules of normal physics and mechanical properties that all of our boats seem to adhere to.
Posted By: GKelly

Re: anyone know anything about prop pitch? - 02/19/19 11:23 PM

Originally Posted by Hevishot13
Originally Posted by rulebreaker
Originally Posted by Hevishot13
Several general rules with props:

1: if going from an aluminum to a stainless prop, always drop down one pitch given that everything else stays the same (ie. the same boat, engine, load, prop style, prop brand). Stainless props are heavier thus harder to turn than a lightweight aluminum.

2. A 4 blade prop with have better load carrying tendencies (to an extent) than a 3 blade, but will also be slower (there’s a few exceptions) than a 3 blade. More wheel to spin, therefor more drag in the water. Pitch and diameter will effect both 3 and 4 blade props differently

3. A 4 blade with have more bite than a 3 blade, but will also cause the boat to be harder to maneuver than a 3 blade ( with a few exceptions)

4. Changing 1 pitch size with change the engines Rpms an average of 150 give or take.

5. No two props are alike. This 23 tempest and that 23 tempest will not run the same nor will they have the same tendencies on the same application. Mercury’s stainless props are machine ground on the trailing edge where as Yamaha’s are done by Mexicans. Ymmv


I know that you are in the business an supposed to know what you are saying, but my experience has always been that for example a 21PSS vs. 21alum. the SS prop will out perform on both ends of the spectrum, holeshot and top end speed due to the flex of the alum. prop. That being said, if you are switching to SS from alum. then you can always go up one pitch, not down.
Also, every single time that I have tried a four blade, it was like I had added super easy power steering to the boat, not harder to maneuver at all, much easier. That's been my 40+ yrs of experience anyways.


man I swear, I’m done commenting on the fishing forum. Good luck to yall

got a question for heavy shot. If I go from a 10.6x12 3 blade aluminum that I'm currently running 6200 rpm at WOT and 34mph to a 10.3x13 4 blade aluminum do you think itll get my rpm below 6000 and improve my hole shot or speed any? I'm more concerned with just getting my rpm down since the motor is rated for 5500-6000 at WOT I dont like it going over 6000. but if I can squeeze a little better hole shot out of it without losing too much top end at the same time I'd like to. I'm wondering if I could possibly go with a 14p since I'm at 6200 rpm but I dont want to feel bogged coming out the hole.
Posted By: rulebreaker

Re: anyone know anything about prop pitch? - 02/20/19 06:44 PM

Originally Posted by GKelly
Originally Posted by Hevishot13
Originally Posted by rulebreaker
Originally Posted by Hevishot13
Several general rules with props:

1: if going from an aluminum to a stainless prop, always drop down one pitch given that everything else stays the same (ie. the same boat, engine, load, prop style, prop brand). Stainless props are heavier thus harder to turn than a lightweight aluminum.

2. A 4 blade prop with have better load carrying tendencies (to an extent) than a 3 blade, but will also be slower (there’s a few exceptions) than a 3 blade. More wheel to spin, therefor more drag in the water. Pitch and diameter will effect both 3 and 4 blade props differently

3. A 4 blade with have more bite than a 3 blade, but will also cause the boat to be harder to maneuver than a 3 blade ( with a few exceptions)

4. Changing 1 pitch size with change the engines Rpms an average of 150 give or take.

5. No two props are alike. This 23 tempest and that 23 tempest will not run the same nor will they have the same tendencies on the same application. Mercury’s stainless props are machine ground on the trailing edge where as Yamaha’s are done by Mexicans. Ymmv


I know that you are in the business an supposed to know what you are saying, but my experience has always been that for example a 21PSS vs. 21alum. the SS prop will out perform on both ends of the spectrum, holeshot and top end speed due to the flex of the alum. prop. That being said, if you are switching to SS from alum. then you can always go up one pitch, not down.
Also, every single time that I have tried a four blade, it was like I had added super easy power steering to the boat, not harder to maneuver at all, much easier. That's been my 40+ yrs of experience anyways.


man I swear, I’m done commenting on the fishing forum. Good luck to yall

got a question for heavy shot. If I go from a 10.6x12 3 blade aluminum that I'm currently running 6200 rpm at WOT and 34mph to a 10.3x13 4 blade aluminum do you think itll get my rpm below 6000 and improve my hole shot or speed any? I'm more concerned with just getting my rpm down since the motor is rated for 5500-6000 at WOT I dont like it going over 6000. but if I can squeeze a little better hole shot out of it without losing too much top end at the same time I'd like to. I'm wondering if I could possibly go with a 14p since I'm at 6200 rpm but I dont want to feel bogged coming out the hole.


It will get your RPM down and it will hurt your holeshot if your going to stay with aluminum.
Posted By: rulebreaker

Re: anyone know anything about prop pitch? - 02/23/19 04:07 PM

Originally Posted by Hevishot13
.
Posted By: lances

Re: anyone know anything about prop pitch? - 02/24/19 05:20 PM

Originally Posted by Hevishot13
Originally Posted by rulebreaker
Originally Posted by Hevishot13
Several general rules with props:

1: if going from an aluminum to a stainless prop, always drop down one pitch given that everything else stays the same (ie. the same boat, engine, load, prop style, prop brand). Stainless props are heavier thus harder to turn than a lightweight aluminum.

2. A 4 blade prop with have better load carrying tendencies (to an extent) than a 3 blade, but will also be slower (there’s a few exceptions) than a 3 blade. More wheel to spin, therefor more drag in the water. Pitch and diameter will effect both 3 and 4 blade props differently

3. A 4 blade with have more bite than a 3 blade, but will also cause the boat to be harder to maneuver than a 3 blade ( with a few exceptions)

4. Changing 1 pitch size with change the engines Rpms an average of 150 give or take.

5. No two props are alike. This 23 tempest and that 23 tempest will not run the same nor will they have the same tendencies on the same application. Mercury’s stainless props are machine ground on the trailing edge where as Yamaha’s are done by Mexicans. Ymmv


I know that you are in the business an supposed to know what you are saying, but my experience has always been that for example a 21PSS vs. 21alum. the SS prop will out perform on both ends of the spectrum, holeshot and top end speed due to the flex of the alum. prop. That being said, if you are switching to SS from alum. then you can always go up one pitch, not down.
Also, every single time that I have tried a four blade, it was like I had added super easy power steering to the boat, not harder to maneuver at all, much easier. That's been my 40+ yrs of experience anyways.


man I swear, I’m done commenting on the fishing forum. Good luck to yall


Solid advise!!
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