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Old 06-10-2008, 06:10 PM
Ballshak31 Ballshak31 is offline
 
Join Date: Jun 2008
Rep: 10 Posts: 2
Location: nc
1980 23.6 Mako Prop size info

Heavey boat. I have a 1980 Mako 23.6 inboard 350 Crusader 260 hp. velt 1.88 to 1. weight 4000 plus some ?
recommended wot tac 4000 to 4400. present prop 16x16 3 blade top rpm 4700 speed 23 mph. plains good but looking better cruise speed and fuel consumption. any suggestion?? thks
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Old 06-10-2008, 06:43 PM
Jango Jango is offline
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Join Date: Aug 2005
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Location: Mid Atlantic
16 x 16, 3 blade is too small. You're getting alot of slippage.

Using 4800 LB total weight with Driver and minimum fuel, calculations show a 18 x 18, 3 blade (.55 D.A.R. min.) or if you don,t have space a 17 x 18, 4 Blade (.63 D.A.R. min). Drive ratio 1.88 to 1

With 260 HP, you should get 35 MPH @ 4400 rpm.
RPM @ cruise will be reduced and fuel consumtion should be noticeably less.

Keep in mind, the above numbers are only correct for 260 HP and 4800 lb total weight. If your minimum total weight is higher, Pitch will be less and perhaps Dia larger.
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Old 06-10-2008, 09:10 PM
Ballshak31 Ballshak31 is offline
 
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Location: nc
In the Know Thks

I sorta felt "small" was the word.... It was nice to hear from some is "IN THE KNOW". Glade i registered!!! Thks Bob in East Coast NC!
Jango...18x21 4 blade too much right?

Last edited by Ballshak31 : 06-10-2008 at 09:26 PM. Reason: question
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Old 06-10-2008, 09:42 PM
Jango Jango is offline
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WAY TOO MUCH, you'll bog the Engine down.

18x21 4 blade would be OK for a 360 HP Big Block or diesel.

Last edited by Jango : 06-11-2008 at 08:26 AM. Reason: spelling & clearification
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