Checked the boat speed today, with the GPS

204 Escape

Ensign
Joined
Nov 17, 2007
Messages
909
Our boat is a 2006 LARSON 204 Escape F/S Deck boat. It has a 5.0 carburated engine, with a Alpha One unit, and a 19 pitch aluminum prop. The boat is 20'-1" in length. The brochure says that it weighs 3,100 #'s Holds 50 gallons of fuel. Has a deadrise of 17 degrees, Transom angle of 14 degrees. It is a modified "V". It is a 220 h.p. engine.

According to the GPS, the following notes are what it read today, on the water, with a full tank of fuel, and "4" people. Weight of the people is approx. 496 #'s.

Speeds/rpm's, and speedometer speeds were as follows:



RPM's GPS Speed Speedometer speed

3250---------------- 32 ---------------- 36
3950---------------- 37 ---------------- 40
4900---------------- 45 ---------------- 50



I was wanting a little more top end. We pull a tube with the boys in it, for a combined weight of +/- 190 #'s

At one time, it was suggested that I go to a 18" pitch, 4-blade unit. NO SPEED was mentioned, so I don't know what to expect out of it.

Any suggestions ??

Thanx,

204 Escape
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Checked the boat speed today, with the GPS

If you are at 4900 at wide open throttle with a 19P prop, you would over rev with an 18. The correct prop is one that allows the engine to operate at the high end of the manufacturers recommended wide open throttle rpm. Speed will be whatever that prop provides. More pitch you lug the engine. Less pitch your over rev. Happiness is in between.
 

junior1113

Senior Chief Petty Officer
Joined
Jan 29, 2009
Messages
763
Re: Checked the boat speed today, with the GPS

18p 4 Blade Will Out Perform A 3. U COULD EXPECT A BETTER HOLE, SHOT SLOWER PLANE SPEED, BETTER MID RANGE FUEL ECCONOMY, AND WILL PROB BE THE SAME. IF TOP END SPEED IS ALL YOU WANT HIGH PERFORMANCE 3 BLADE USSUALY IS BEST
 

hwsiii

Commander
Joined
Jan 25, 2009
Messages
2,639
Re: Checked the boat speed today, with the GPS

Escape, I found the boat to weigh 1,800 pounds instead of 3,100 pounds and the gear ratio to be 1.62 and a recommended RPM range of 4,400 to 4,800 RPM, if this is wrong please let me know as my numbers will be off. With using the following numbers I found your boat should be using a 19" Pitch 4 blade propeller and you should be turning right at the top of your RPM range at about 48 MPH and the 4 blade will help with hole shot, tubing and your mid range cruising speeds and should bring your prop slip down from the 17% it is now. Here are my numbers.

Boat and Motor

204EscapeBoatandMotor.jpg


Prop Picker

204EscapePropPicker.jpg



Prop Change


204EscapePropChange.jpg


H
 
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