Anonymous
01-22-2003, 10:38 PM
INCOMMUNICADO
normal member in standard member. 1. Prop info on 220WA
I have a 1996 220WA with a 350-2V Indmar engine with 1:1 transmission. I have been reading all of the post and replies on prop size, pitch, RPM and speed and felt that my boat was a little slow at cruise RPM, almost like a car in second gear.
With a load of 500 lbs plus 90 gal of fuel and 20 gal of water. I made several rpm/speed readings with the prop that was on the boat when I purchased it last year. Readings were taken on a calm day on a small lake using my GPS. I keep the boat on a lift so I do not have to use bottom paint. I also trimmed the boat at each RPM for max speed. I pulled the boat last week to check the prop, it was a three blade stamped 14X11LH. I took it to our local prop repair shop and it measured out as a 14x10 at a point 2/3 the distance from the hub. We decided to repitch the prop to a 14x11 on the first 1/3 and 14x12 on the middle 1/3 and 14x13 on the tips (no cupping).
The WOT dropped from 4950 to 4000 (a little low), but top speed only changed from 30 up to 31 MPH. I did not notice any change in operating temperature (raw water). I also added a vacuum gauge and found that the best RPM for gas mileage is 2600 for this setup.
Before---RPM----After
17.5----2600----24.0 MPH
19.2----2800----25.4 MPH
20.9----3000----26.8 MPH
22.8----3200----28.1 MPH
30.0----WOT----31.0 MPH
I really like the increased cruising speed. I have to travel 28 miles to get to the Gulf, and on a round trip I save 30 to 40 minutes of running time. I noticed that the boat comes out of the hole faster.
I also read where several boat owners were having problems with enough electrical power because Shamrock uses size 24 batteries. I replaced the battery board support with 3/4" marine plywood that was 2 inches wider and rotated my batteries 90 degrees (running lengthwise with the keel), this enabled me to add an additional battery and a battery isolator all on the same board. I now have a dedicated starting battery and two deep cycle batteries to power my accessories, which includes a 1800 watt inverter to supply 120VAC for my refrigerator, microwave and electric knife, plus all of the 12 volt DC items such as GPS, radios, pumps, lighting and toilet.
I hope that this info may be of some help.
Date: 01:31 a.m. on 04-28-2001
Capt_Dog
premium member in standard member. 2. Re:Prop info on 220WA
That is remarkable. I have the same package, although 1992 220 WA with the 351 Indmar. My perfomrance mirrors your "before" numbers. I cannot believe you got 6mph more out of of 3000 cruise. A couple of questions, if you do not mind. Does your boat have bottom paint? If so is your running gear (Rudder, prop) painted? What is the advertised HP of your 1996 motor (example mine has 240)? What was your best trim (Motorboat Mag said 7 degrees was their best)?
--------------------------------------------------------------------------------
Thanks, Lee
Date: 07:32 a.m. on 04-30-2001
normal member in standard member. 1. Prop info on 220WA
I have a 1996 220WA with a 350-2V Indmar engine with 1:1 transmission. I have been reading all of the post and replies on prop size, pitch, RPM and speed and felt that my boat was a little slow at cruise RPM, almost like a car in second gear.
With a load of 500 lbs plus 90 gal of fuel and 20 gal of water. I made several rpm/speed readings with the prop that was on the boat when I purchased it last year. Readings were taken on a calm day on a small lake using my GPS. I keep the boat on a lift so I do not have to use bottom paint. I also trimmed the boat at each RPM for max speed. I pulled the boat last week to check the prop, it was a three blade stamped 14X11LH. I took it to our local prop repair shop and it measured out as a 14x10 at a point 2/3 the distance from the hub. We decided to repitch the prop to a 14x11 on the first 1/3 and 14x12 on the middle 1/3 and 14x13 on the tips (no cupping).
The WOT dropped from 4950 to 4000 (a little low), but top speed only changed from 30 up to 31 MPH. I did not notice any change in operating temperature (raw water). I also added a vacuum gauge and found that the best RPM for gas mileage is 2600 for this setup.
Before---RPM----After
17.5----2600----24.0 MPH
19.2----2800----25.4 MPH
20.9----3000----26.8 MPH
22.8----3200----28.1 MPH
30.0----WOT----31.0 MPH
I really like the increased cruising speed. I have to travel 28 miles to get to the Gulf, and on a round trip I save 30 to 40 minutes of running time. I noticed that the boat comes out of the hole faster.
I also read where several boat owners were having problems with enough electrical power because Shamrock uses size 24 batteries. I replaced the battery board support with 3/4" marine plywood that was 2 inches wider and rotated my batteries 90 degrees (running lengthwise with the keel), this enabled me to add an additional battery and a battery isolator all on the same board. I now have a dedicated starting battery and two deep cycle batteries to power my accessories, which includes a 1800 watt inverter to supply 120VAC for my refrigerator, microwave and electric knife, plus all of the 12 volt DC items such as GPS, radios, pumps, lighting and toilet.
I hope that this info may be of some help.
Date: 01:31 a.m. on 04-28-2001
Capt_Dog
premium member in standard member. 2. Re:Prop info on 220WA
That is remarkable. I have the same package, although 1992 220 WA with the 351 Indmar. My perfomrance mirrors your "before" numbers. I cannot believe you got 6mph more out of of 3000 cruise. A couple of questions, if you do not mind. Does your boat have bottom paint? If so is your running gear (Rudder, prop) painted? What is the advertised HP of your 1996 motor (example mine has 240)? What was your best trim (Motorboat Mag said 7 degrees was their best)?
--------------------------------------------------------------------------------
Thanks, Lee
Date: 07:32 a.m. on 04-30-2001