Prop recommendation to correct tendency to cavitate

high&dry

Seaman
Joined
May 18, 2018
Messages
61
High&dry, what kind of boat? Are you looking for an enertia or enertia eco? The enertia is also sold as the Quicksilver q3 for a few hundred less. If you can find one.

Well, I will not rob the thread. My boat is a BW Nantucket 190. I would want an Enertia, not an Eco.

I cannot be certain of couse and props are expensive to play with but I am sure the OP could be better with a good stainless prop, maybe 2 inches less pitch and a four blade prop would really bite.

The Enertia is somewhat a three blade Revolution 4, similar blade designs, just one less.
 

porscheguy

Chief Petty Officer
Joined
Jan 17, 2013
Messages
441
I think you’ve mentioned this before. All I know for certain is that if I walk into general propeller in Bradenton and ask for an enertia, they’ll strongly urge me to save a few hundred and take the Q3. I don’t doubt your claim of subtle differences. I’m actually curious to know what they are.

As for the revolution4, it’s actually a 4 blade Tempest plus.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,785
If you want to stay in aluminum yes the Turning Point Hustler is a good choice. I have one and, as advertised, it has all the amenities of the SS high performance less the steel....but it has a special aluminum that allows for thinner blades than normal thicknesses of alum props of the series.

Cupping of the trailing edge of the prop is your main solution to holding in turns.

Other problems are trim out too far for the speed and angle of the turn and hull irregularities (or anything else) generating turbulence in front of the engine skeg, generated by things attached to the transom (trim tabs, speedometer, depth sounder) or the shape of the hull at the transom..... keel protrusion, lifting strakes, deep V dead rise, dirty hull (slime), Barnacles (in salt water)........

Yes, once you "blow out" recovery is usually chop the throttle and restart...but you can do that in a second...down and back up.

The tighter the turn and higher the speed, the easier it is to produce a "ventilation" reduction in thrust. Cavitation is usually at blade tips (rough edges....lower pressures create tiny vacuums....the bubbles), not that big of a deal...lots of little bubbles that follow the prop, not like ventilation that interferes with new water entering the prop. or the sucking of surface air into the prop wash.
 

SkiGuy1980

Petty Officer 2nd Class
Joined
Aug 10, 2017
Messages
138
Thanks for the feedback all. I'm going to follow up with Hearne Marine regarding possible change to SS. They were generally discouraging a switch to stainless (cost primarily... and bigger dollars to replace if you jack it up), but I think it will help minimize the cavitation.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,677
There is another thing to consider regarding costs, an AL prop will bend, chip, break far easier, and may spare the rest of the drivetrain damage. A Stainless, being much stronger will not yield as easily, and will keep banging/hammering until it shapes into a ball. Bent prop shafts are common when SS prop are used and and big rocks hit

My Raker after Rocks at 20mph, bent the Propshaft too with less than 10 hrs
img579b.jpg
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
Good luck, but maybe bare in mind what I mentioned about the RPM range.
 

SkiGuy1980

Petty Officer 2nd Class
Joined
Aug 10, 2017
Messages
138
Thanks QBhoy... The RPM comes from the manual on the 350 mag mpi. I think stepping down to a 19 four blade (currently 21/3) will improve holeshot. I know it will shave some off the topend... maybe 5 mph... but I'll still be a tad over 50.
 

SkiGuy1980

Petty Officer 2nd Class
Joined
Aug 10, 2017
Messages
138
Thought I'd give a brief update on the prop situation...

I had a new prop put on last week and finally got a chance to give it a run this evening. I'd had a 21 pitch 3 blade aluminum and the boat was slow out of the hole (really pronounced when pulling a skier) and had a tendency to cavitate. The service mgr at my marine dealer had ran the same model boat as mine last year and recommended an 18 pitch 4 blade stainless. Wow! That thing is like a rocket out of the hole! Bow rise almost gone and maybe lost a mile at top end (still run 55). Cavitation is greatly improved. The only negative I could note is that the additional torque seems to be tilting the boat slightly (high on starboard side). Not too bad and the better hole shot makes it worth it.
 
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