What prop

armymike63b

Cadet
Joined
May 12, 2009
Messages
14
I have an 87 Glastron Conroy Z-16 with an 88hp evinrude does anyone know what the stock prop size is and what's the diff between 3 and 4 blade ?
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: What prop

Props are a dealer installed item, there is no "stock" size.

What is on it now, and what are your WOT numbers.
 
Joined
Jul 30, 2008
Messages
172
Re: What prop

4 blades are completely unnecessary (more drag) unless you're running a surfacing prop on a raceboat. You can go to Dan's discount Props, e.g., and look at the range of pitches offered for your motor. I don't know the gear ratio of your motor, but would expect that with a 1970s-1980s 135 or 140 and your heavy boat you'd likely need about 19"-21" pitch. The 135s and 140s were geared 2:1.



I have an 87 Glastron Conroy Z-16 with an 88hp evinrude does anyone know what the stock prop size is and what's the diff between 3 and 4 blade ?
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: What prop

4 blades are completely unnecessary
Funny you mention Hill in another post as a good prop source, he even makes a six blade . . . You should call Ron and tell him that his four blades are "unnecessary". I am currently running one of his and it is comparable to the Merc Bravo 1 four blade that is obviously even more common. You need to brush up on the current state of recreational props ;)
 
Joined
Jul 30, 2008
Messages
172
Re: What prop

All sorts of things have been tried, not all work, and not all are improvements. I'm not up on commercial offerings. My main interest is in surfacing props. I can imagine that 4 blades may be smoother than 3, I can also guess that 4 blades submerged drag more than 3. Six blades?!



Funny you mention Hill in another post as a good prop source, he even makes a six blade . . . You should call Ron and tell him that his four blades are "unnecessary". I am currently running one of his and it is comparable to the Merc Bravo 1 four blade that is obviously even more common. You need to brush up on the current state of recreational props ;)
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: What prop

I'm not up on commercial offerings...

Then why say "4 blades are completely unnecessary" if you don't know.

That extra blade makes a big difference in hole shot, typicaly has better midrange acceleration and holds plane at slightly lower speed. Low speed handling is vastly improved, especially in reverse.

Is there an efficiency hit, sure. Most boats will loose 1-2mph off the top end, but your average recreational boater spends alot more time cruising and pulling tubes, skiers etc than they do running WOT.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: What prop

I'm not up on commercial offerings.
But that's what most of our members are concerned with . . . ;)

Take a look at the Sticky ^^^^ with Walleyeheds test results. A little (lot) hard to read, but there is some very good data there.
 
Joined
Jul 30, 2008
Messages
172
Re: What prop

Yep, and I'm here for the 1% who want something more than tubing, etc!


But that's what most of our members are concerned with . . . ;)

Take a look at the Sticky ^^^^ with Walleyeheds test results. A little (lot) hard to read, but there is some very good data there.
 
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