PDA

View Full Version : Propeller Question



Germancar90
10-07-2013, 02:38 PM
Hey All,

Quick question looking for your opinions. I have an 18 classic with a 300hp 350 Chevy bolted to a gen 2 alpha. Currently there is a 3 blade 14x24 pitch stainless wheel on the boat and it only turns 4000 id like to get the boat to turn around 5000 what should I get for a propeller? I was thinking a 14 1/2 x 21 would get the job done as well as give me ample bow lift but not sure what do get mirage, Yamaha etc etc? What are your opinion's, I'm sure this question has been asked a million times on here so sorry if that's the case.

Thank you!

Pat McPherson
10-07-2013, 04:27 PM
2" of pitch is normal worth 300-400rpm but your engine is overloaded if she's only getting to 4000.
You will want to confirm your drive ratio. If it's a 1.3 you'll probably want a 19p, if 1.5 then 21p.
I ran a 23p Mirage on my 20' Minx with a small block Alpha and at WOT she was about 4600rpm running light with 270HP and 4800rpm with 300HP.
Both a Merc Mirage and Turbo 1 work well on my 22' Classic.

joseph m. hahnl
10-07-2013, 06:05 PM
2" of pitch is normal worth 300-400rpm but your engine is overloaded if she's only getting to 4000.
You will want to confirm your drive ratio. If it's a 1.3 you'll probably want a 19p, if 1.5 then 21p.
I ran a 23p Mirage on my 20' Minx with a small block Alpha and at WOT she was about 4600rpm running light with 270HP and 4800rpm with 300HP.
Both a Merc Mirage and Turbo 1 work well on my 22' Classic.
I don't think they make a gen 2 Alpha with 1:3 gear set:kingme:. Bravo's took over that chore:yes: .

I think that the stock prop for an 350 mag is a 21P. My Mirage Carries the bow well and being a three blade, you can get some slip to break them loose:biggrin:

Germancar90
10-22-2013, 08:48 AM
I don't think they make a gen 2 Alpha with 1:3 gear set:kingme:. Bravo's took over that chore:yes: .

I think that the stock prop for an 350 mag is a 21P. My Mirage Carries the bow well and being a three blade, you can get some slip to break them loose:biggrin:


Do you know the diameter of the propeller that you are running?

tmdog
10-22-2013, 10:03 AM
Pretty sure the Mirage is 14 5/8" and the Turbo 1 is 14 1/4".

MOP
10-22-2013, 03:11 PM
IMO you are right on a 21 3 blade, that should put you at about 46-4700.

smokediver
10-24-2013, 09:56 PM
are you trimming it out ? you should be able to turn a mirage plus 23p with that set up .