Pre-78 - limited pitch selection- WHY?

O

odyaxchad

Cadet
Joined
Oct 7, 2012
Messages
8
I have the pin type prop set-up, a 1977 Century, 235 HP, 351 Ford V8,, OMC outdrive, and can only find about 3-4 different pitches, all too low for what I want, 16 pitch being the highest.....Why do they not go up higher in pitch for the pin type prop set-up? After 77, 1978 for example you have a wide selection of pitch for props, 21 pitch and higher,......?
Can one pound out a 20 from a 16 or 17 pitched prop? I want more top end, higher cruising speed, please help.

Later..........Chad on the Shadowy St. Joe river.
 
S

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Pre-78 - limited pitch selection- WHY?

Very likely the prop pitch is directly affected by the gear ratio.Do you know your gear ratio?It may be on your outdrive.
Are you aware that you can't just arbitrarily change your pitch. Your motor needs to operate within a specific wot rpm rating and prop pitch is the major way to reach the proper rpm.
What is your present prop size and wot rpm and gps speed?
 
jestor68

jestor68

Commander
Joined
Jun 12, 2012
Messages
2,308
Re: Pre-78 - limited pitch selection- WHY?

There was always a limited selection of props for that first gen drive; if you call a selection from 10-20 pitch in aluminum, and 13-19 pitch in SS limited.

1978 is when OMC came out with the second(?) generation drive that used the thru bub type exhaust.

Propco Propellers still makes props for your first gen drive. They are all 14" diameter and available in 12,14,16, and 18 pitches for $160 according to their web site.

The OMC part # for the 14 X 20 aluminum is 0383287. Good luck finding one.
 
Last edited:
You must log in or register to reply here.
Top