THE REAL REFERENCE FOR THIS PROPELLERS ??

[FRANCISCO BORJA REIS]

Topic

[Tony Athens]

Francisco,

#1———-If your Cummins 6BTA 5.9 370 Diamonds are in tip-top shape, then understand this if you want for the best possible performance, coupled to overall economy, ability to jump up on plane easily and then attain the  long term reliability.

For PROPPING PURPOSES, you have 355 BHP at 3125-3150 RPM  to work with. That means your engines MUST easily spin up to well over 2900 RPM while accelerating and then be able to attain over 3100 RPM under fully loaded conditions at WOT after the boat settles down at reaches top speed..

In the case of your 36 Hatteras, it will all come down to how heavy your boat gets  as to need to use it..With 1.5:1 gears, I’d be looking at something like high end ACME 21×21  3B’s light cup as long as you have not less than 2.5″ of tip clearance..If you only have room for 20″ diameter, go with a 20 x 21″ 4B with a light cup cup..  Lots of things go into propeller selection, at  you have not given us much other than you have a 36 Hat with 370 B’s..If your boat gets super heavy, my suggestion may have to be toned down–The key is reaching OVER 3100 and doing it easily..

 

Hope this helps.

 

Tony

 

 

 

 

[FRANCISCO BORJA REIS]

Good afternoon, my HATTERAS 36 Convertible – Series I has 2 engines Cummins of 370 hsp model 6BTA 5.9. The box is a twin disc MODEL Nº MG-507-1 , RATIO 1.51:1 SERIAL Nº 5 FY065
I would like to know witch propellers is the best for my boat.i like one that give me the max confort , speed and economie.

[Rob Schepis]

Likely a cupped Nibral 4-blade.  You did not tell us anything about the boat, engines/gears, etc. etc.

Play with this:

https://www.vicprop.com/planing_size.php

[FRANCISCO BORJA REIS]

I AGREE WITH YOU, I WOULD LIKE TO KNOW WHAT WOULD BE THE CORRECT PROPELLERS FOR THIS BOAT ??

[Rob Schepis]

Other than looking fancy….to me they look inefficient and expensive to purchase and repair/recondition.  What is your question?  Was your subject line supposed to read [The Real “Difference” for These Propellers?]

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