Update: Boat gas usage per set

[skierjp]

Whoops my mistake I meant.

 

1868 ( 5.7 liter ) is stamped near the nut. This is the approved prop by AWSA. NOT 422 sorry.

 

It's way to early in the morning for this !!!

[ForrestGump]

FWIW, the 654 on a 5.7 works really well too. It turns about 100 more rpm than the 422, and 250 less than the 1868. My thought is that it would pass the jump acceleration test that the 422 failed if they'd submit it.

[usaski1]

Not to thread jack, but I guess that's what I'm doing: Last night I noticed I'm turning 3700 rpm for 30mph. prop is 13x13 OJ. Top end with 325hp (indmar) non-existant.. 38mph. Boat seems like its running fine. Any Ideas? Kinda seems like I'm burning gas like crazy too..

[DW]

Tweaking on a prop is not hard, particularly a Nibral one, much easier than a stainless. You can easily change the characteristics of any given prop. I added cup to a used Acme I bought (from another baller to be exact) and made it do what I wanted. To Roger, you can't tell unless you were to actually measure the cup on the prop I modified. End result, kept the great holeshot and dropped the rpm by 200, which is what I was after. On the old CVP, I sharpened the blades, roughed up the surface and added cup to eliminate the cavitation, also improved that prop quite a bit (it actually still has all three blades, a notorious failure mode for those).

 

Blueprinting a prop can produce some really good results depending on what you are after. Boat racers spend lots of time detailing the tuning the prop to optimize performance, and they can cut anything with them when done.

[thompjs]

If it gets repaired, it could be anything.