prop recomendations

26aftcab454

Lieutenant Commander
Joined
May 12, 2009
Messages
1,510
bought a perfect 1981 Glastron SX 190 with a slightly tuned 300hp 350 chevy.
the prop is a SS 3 blade "5070 14"x19" the drive is a Alpha 1.
The boat is light weight bow rider -total rebuild in 2010- no water soaked foam-and runs good at
50ish mph till 4000rpm WOT. no more.
I'm thinkin it should hit higher WOT in the upper 4000s rpm closer to 5000 rpm range at a higher speed. It has a heck of a holeshot & rapid acceleration but thinkl it could be better.
sorry no more info .:facepalm: All I can find.
Input is appreciated.
 
Last edited:

Robbabob

Senior Chief Petty Officer
Joined
Jun 5, 2009
Messages
678
Re: prop recomendations

What is the max HP rating for that boat?
 

reddogg

Petty Officer 1st Class
Joined
Jun 3, 2011
Messages
379
Re: prop recomendations

Going up or down a pitch is worth about 200rpm.

red
 

QC

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

Do you have the gear ratio? If it's a 1.5 then the tach is off, or some other piece of data is wrong.

Whenever anybody says they have great hole shot and yet can't get to WOT RPM it is a clue as to bad data ;) Garbage in = garbage out. Sumpin's garbage :)
 

26aftcab454

Lieutenant Commander
Joined
May 12, 2009
Messages
1,510
Re: prop recomendations

now I'm thinking it may be the tach too-- it runs great---tach says I'm idling at less than 500 rpm and cruise 28 to 30 mph at 2500 rpm.
it makes sense
 

QC

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

Ding, ding, ding, we have a winner. Check the back of your tach for the proper setting for V8 ;)
 
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