- Aug 20, 2021
- 1,314
- Boat Info
- Started out as MAYBE A DANCER
Became a Dancer - 12/23/21
- Engines
- 450 DA Sundancer running CAT 3126
Several issues here, so I'm trying to learn all I can on this topic.
Running a 450DA with 3126TA Cats
Installed the FLOSCAN digital tach/flowmeter system from my 10 Meter Trojan International's Yanmar diesels to the Sundancer.
Calibrated and verified my fuel burn this summer on the 660 mile Florida Loop, and am very happy with the results, especially seeing the live data when running half fuel and water in a calm sea.
I've reduced the factory props down twice to reach 2800WOT with full fuel, water and 30% blackwater, and I am now at the max reduction for this set of propellers.
This boat runs a little heavy with fwd & rear bow thrusters, 7 batteries, cablemaster and vinyl plank flooring throughout.
I've worked with General Propeller on my last diesel boat, where on their recommendation, I upgraded to VEEM propellers.
General Propeller has recommended that I upgrade these props to 5 blade VEEM propellers, claiming there will be an additional1-2 knots and far better efficiency.
In ordinary situations given the cost, this upgrade would not make sense.
However this is (yeah, you've heard this before) my last boat. I'm 64 and the express layout combined with the remote I installed for both thrusters and the cablemaster, I should be capable of continuing to single handle her until reaching the point where my health fails me.
She's no dock queen she's been to Key West, Sarasota and just completed the Florida Loop through Marathon. I joined AGLCA this year and plan on extending these adventures to include the Bahamas and extended runs on both coasts. No immediate plans to do the loop right now, but that may be a future target depending on my situation. This boat is going to be run, go places and will be burning some fuel. Increasing cruise speed and efficiencies could even expand my between port distances.
I have no spare props, and I'd feel better carrying a set for a future Bahamas run.
Boat comes out of the water for a bottom job soon, and I'll have an accurate weight on her.
Currently running 22 x 22.5" props.
Not entirely "sold" on the VEEM 5 blade prop idea. I have a pair of same shaft 1.75" diameter Michigan wheels from my last boat, 20x20 Nibral which might be adequate spares in a pinch if I damaged something in the Bahamas.
So, where is this post going?
I've confirmed my FLOSCAN fuel burn data to be accurate within 4.5%
The 3126 CATS are rated to safely run 2400 RPM continuously. Surprised that my most efficient cruise RPM's (50% fuel and water) are 2250-2400 @ 24-26 SMPH burning .89 - .94 SMPG. Not too shabby for a 45' express likely weighing in at well over 30,000 lbs.
These efficiencies drop significantly at fully loaded fuel & water, especially in rougher seas. .79 - .82 SMPG at 20-21 SMPH
The Floscans give me the ability to have real time (now verified) instant data, combined and or separately and for both motors at any speed/rpm/load.
The data demonstrate that my actual fuel burn is significantly higher than the CAT prop curve data, which according to all known, experienced, sources, is extremely accurate.
Here's what I have:
Planing speed is 1800 RPM.
It's interesting to see the net difference between the CAT published Prop Demand GPH vs. actual data.
Remember, I am making 2800 WOT fully loaded.
Most owners of this exact hull/engine combination report best efficiencies at 1900-2200 RPM, with a sweet spot at 2150 RPM.
Seeking comments regarding the significant difference between the CAT table and my own data.
Also, given that I've taken as much off current props as possible, should I consider making those the "spares" and getting the VEEM 5 blades as an option, once I have an accurate weight for this vessel?
BEST !
RWS
Running a 450DA with 3126TA Cats
Installed the FLOSCAN digital tach/flowmeter system from my 10 Meter Trojan International's Yanmar diesels to the Sundancer.
Calibrated and verified my fuel burn this summer on the 660 mile Florida Loop, and am very happy with the results, especially seeing the live data when running half fuel and water in a calm sea.
I've reduced the factory props down twice to reach 2800WOT with full fuel, water and 30% blackwater, and I am now at the max reduction for this set of propellers.
This boat runs a little heavy with fwd & rear bow thrusters, 7 batteries, cablemaster and vinyl plank flooring throughout.
I've worked with General Propeller on my last diesel boat, where on their recommendation, I upgraded to VEEM propellers.
General Propeller has recommended that I upgrade these props to 5 blade VEEM propellers, claiming there will be an additional1-2 knots and far better efficiency.
In ordinary situations given the cost, this upgrade would not make sense.
However this is (yeah, you've heard this before) my last boat. I'm 64 and the express layout combined with the remote I installed for both thrusters and the cablemaster, I should be capable of continuing to single handle her until reaching the point where my health fails me.
She's no dock queen she's been to Key West, Sarasota and just completed the Florida Loop through Marathon. I joined AGLCA this year and plan on extending these adventures to include the Bahamas and extended runs on both coasts. No immediate plans to do the loop right now, but that may be a future target depending on my situation. This boat is going to be run, go places and will be burning some fuel. Increasing cruise speed and efficiencies could even expand my between port distances.
I have no spare props, and I'd feel better carrying a set for a future Bahamas run.
Boat comes out of the water for a bottom job soon, and I'll have an accurate weight on her.
Currently running 22 x 22.5" props.
Not entirely "sold" on the VEEM 5 blade prop idea. I have a pair of same shaft 1.75" diameter Michigan wheels from my last boat, 20x20 Nibral which might be adequate spares in a pinch if I damaged something in the Bahamas.
So, where is this post going?
I've confirmed my FLOSCAN fuel burn data to be accurate within 4.5%
The 3126 CATS are rated to safely run 2400 RPM continuously. Surprised that my most efficient cruise RPM's (50% fuel and water) are 2250-2400 @ 24-26 SMPH burning .89 - .94 SMPG. Not too shabby for a 45' express likely weighing in at well over 30,000 lbs.
These efficiencies drop significantly at fully loaded fuel & water, especially in rougher seas. .79 - .82 SMPG at 20-21 SMPH
The Floscans give me the ability to have real time (now verified) instant data, combined and or separately and for both motors at any speed/rpm/load.
The data demonstrate that my actual fuel burn is significantly higher than the CAT prop curve data, which according to all known, experienced, sources, is extremely accurate.
Here's what I have:
CAT GPH | ACTUAL | COMBINED | % | |||
RPM | SMPH | SMPG | COMBINED | GPH | DIFF | DIFF |
1200 | 9.6 | 1.31 | 4.4 | 7.3 | 2.90 | 66% |
1400 | 10.5 | 1.02 | 6.4 | 10.3 | 3.90 | 61% |
1600 | 11.0 | 0.73 | 9 | 15.1 | 6.10 | 68% |
1800 | 16.3 | 0.83 | 12.4 | 19.8 | 7.40 | 60% |
2000 | 19.6 | 0.90 | 16.2 | 21.8 | 5.60 | 35% |
2200 | 23.6 | 0.94 | 20.8 | 25.2 | 4.40 | 21% |
2400 | 26.6 | 0.90 | 26.8 | 29.7 | 2.90 | 11% |
Planing speed is 1800 RPM.
It's interesting to see the net difference between the CAT published Prop Demand GPH vs. actual data.
Remember, I am making 2800 WOT fully loaded.
Most owners of this exact hull/engine combination report best efficiencies at 1900-2200 RPM, with a sweet spot at 2150 RPM.
Seeking comments regarding the significant difference between the CAT table and my own data.
Also, given that I've taken as much off current props as possible, should I consider making those the "spares" and getting the VEEM 5 blades as an option, once I have an accurate weight for this vessel?
BEST !
RWS