Any prop gods about???

Hi all, need a bit of advice, I have a 4 blade 14 1/2  x 15p prop, im getting 6100rmp trimed out and light-ish load, I would really like to hit 6400rpm I can get a hold of a 4 blade 13 3/4 x 17p to try out for a few days, do you think that this prop will exceed 6400?

I have tried the  Revolution 4 17 Pitch (14-5/8x17)  with only 5500rpm

also the Mirage Plus 18 Pitch (15-3/8x18 with only 5700rpm

your thoughts please

Cheers

Darren


Alan James's picture

Posts: 2223

Date Joined: 30/06/09

If no one can help try this guy

Wed, 2011-08-31 17:36

http://www.propellers.com.au/

I think Michael Constantine is his name.  He knows his stuff.

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Posts: 23

Date Joined: 19/10/10

Thanks for the link Alan

Wed, 2011-08-31 17:44

Thanks for the link Alan

nico's picture

Posts: 226

Date Joined: 17/08/10

 what mercury model  and type

Wed, 2011-08-31 21:21

 what mercury model  and type of boat ? Where is the cav olate in relation to the bottom of the hull and do you have setback or wedges?

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In Mocean

strike_zone's picture

Posts: 403

Date Joined: 09/09/10

lower pitch

Wed, 2011-08-31 23:10

you need to go down in pitch to pick up more revs

Posts: 23

Date Joined: 19/10/10

Nico, Motor height is right,

Thu, 2011-09-01 08:45

Nico, Motor height is right,

strike zone, no not really the case, all props are different .....also the prop i have is a 14 3/4 and the one i want to try is a 13 3/4 dia but has (to me) looks like bigger ears and a taller rake in the blades

alfred's picture

Posts: 3097

Date Joined: 12/01/07

Is this on a Verado 150? 

Thu, 2011-09-01 07:14

Is this on a Verado 150?

 

Posts: 23

Date Joined: 19/10/10

No...300 Verado

Thu, 2011-09-01 07:19

No...300 Verado

Brucesta's picture

Posts: 1721

Date Joined: 29/05/09

i would have thought 6100rpm

Thu, 2011-09-01 07:35

i would have thought 6100rpm would be the rev limiter, man my 200 will only pull 5600rpm and thats WOT at 41knots. is it really gonna be worth it? how have the prop changes affected the economy? thats wjhat i'd be looking for

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Las Vegas - Rolling the dice and trying your luck. 1M+ Barra summer target. 100kg Black Marlin winter target

Posts: 23

Date Joined: 19/10/10

G'day Brucesta, well i just

Thu, 2011-09-01 08:14

G'day Brucesta, well i just spent 30+k on a motor so fine tuneing the prop is worth every bit i think, rev limiter hits 6500rpm thats why i would like to see 6400rpm or even hitting the 6500 very light load, this is what the Verado likes, I might even end up taking 10-12mm off the tube length to gain 1-200rpm, I just cant see the sence of someone spending all that $$$$ and not get the most out of it, thats just me, i have always been like this...lol

Posts: 23

Date Joined: 19/10/10

Brucesta, Just out of

Thu, 2011-09-01 08:17

Brucesta, Just out of intrest, what motor do you have... year and HP?

cheers

Brucesta's picture

Posts: 1721

Date Joined: 29/05/09

2009 Yamaha 200hp 4 stroke

Thu, 2011-09-01 08:46

2009 Yamaha 200hp 4 stroke with stock prop 19 inch pitch, 41 knots is enough for me.

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Las Vegas - Rolling the dice and trying your luck. 1M+ Barra summer target. 100kg Black Marlin winter target

Posts: 23

Date Joined: 19/10/10

(No subject)

Thu, 2011-09-01 10:19

Posts: 218

Date Joined: 15/01/10

Some basics to with props.1.

Thu, 2011-09-01 08:44

Some basics to with props.

1. The diameter is the referring to the diameter of the actual prop itself.

2. The pitch refers to the travel of the prop for 1 rotation.

 

Threfore- more revs- smaller pitch

               Less revs- larger pitch

What you should be aiming for is getting the revs range at wot as per the recommenations of the motor.

The you can go into the materials of the prop which will effect the performance also.

 

Basically it is a trial and error to get the correct sizing.

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null

wangler's picture

Posts: 607

Date Joined: 26/04/08

Two props

Thu, 2011-09-01 09:39

Wouldnt 2 different props be ideal, 1 for a full boat (6400 rpm) and the other for a lighter load(6100rpm) ?

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Want to make someone mad... tell a lie! Want to get the world upset... tell the TRUTH !

Dougie

Posts: 23

Date Joined: 19/10/10

Yep right on wangler

Thu, 2011-09-01 10:18

Yep right on wangler

Posts: 877

Date Joined: 03/05/11

If i may ask, why do you want

Thu, 2011-09-01 09:50

If i may ask, why do you want to get the extra 300rpm. Its probably not good for the motor to run at over 6000rpm. I never run mine at top speed because the motor could burn out.

If your going to fly at 40 knots, whats difference is 1 gonna make?

Just my point of view

Benno

Posts: 23

Date Joined: 19/10/10

Giday Benno well i just spent

Thu, 2011-09-01 10:17

Giday Benno

 well i just spent 30+k on a motor so fine tuneing the prop is worth every bit i think, rev limiter hits 6500rpm thats why i would like to see 6400rpm or even hitting the 6500 very light load, this is what the Verado likes, I might even end up taking 10-12mm off the tube length to gain 1-200rpm, I just cant see the sence of someone spending all that $$$$ and not get the most out of it, thats just me, i have always been like this...lol

Tony Halliday's picture

Posts: 2500

Date Joined: 14/06/07

hey just a big thanks to

Thu, 2011-09-01 13:03

hey just a big thanks to Michael at Just Propellors for repair my old allie prop and the great deal on shiny brand new spanking Stainless Steel on as well.

 

ps if you in the market for a SARCAR anchor and bow sprit he is doing some insane magic deals as well...

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Tony Halliday: ~Meals on Reels ~

 It takes a strong fish to swim against the current. Even a dead one can float with it

"It is always in season for old men to learn." Aeschylus (525-456 BC)

"In a mad world only the mad are sane." Akira Kurosawa (1910-1998)