FloScan Install Completed
Posted: Mon Jan 27, 2014 12:17 pm
The Floscan installation has been completed. (photos attached)
I used the factory brackets to attach the port side, and fabricated my own brackets for the starboard side. I took my time with the installation and was careful about the placement of the sensors and the pulsation dampeners with regard to not restricting access to any other engine room mechanical components.
The project took two weekends. All the connections are crimped and sealed with heatshrink tubing. Where multiple wires were exposed, I used a flexible plastic split wire loom. I tagged all my wires with a labelmaker as well as identifying the supply and return units for identification. All wiring and additional fuel hoses are mechanically clamped or ty-wrapped as necessary.
Although the final (fine) calibration is not complete, therefore the data collected cannot be relied on as far as actual burn rates are concerned. A fill up of fuel, a decent run and a final fill up will provide the info needed for final calibration. That said, the data collected thus far does tell us where our sweet spots are and what kind of difference exists incrementally.
Once fine calibration is done, we may likely find some fine tuning of propeller pitch will be required as well.
Prior to the repower, I was running counter rotating Crusader 454 engines. I had an Ensign digital tach/sync and a gasoline Floscan which was deadly accurate to within five gallons on every fill up with no calibration.
The Yanmar 6LP Turbodiesel refit engines are NOT counterrotating. The counter rotation is achieved by running one of the 2:1 ratio ZF 63A gears in FWD and the other in reverse. In this case the Port ratio is 2.04:1 and the Starboard ratio is 2.10:1.
This disparity resulted in the inability to sync the engines by tachometers or by engine sound. The engines were synched by matching the boost pressure.
The Floscan installation and data has disclosed several important bits of information that will have an impact on the performance of this vessel. Among them is:
1. Apparently the VDO tachs were over reporting RPM at higher speeds. It appears that the Floscan digital tach are accurate, however this will be verified with a photo tach soon.
2. Assuming the Floscan tach data to be accurate, we will likely decrease our current 20x20 prop pitch somewhat once all the results are in.
3. At cruising speeds, these turbodiesel Yanmar engines in the 10 meter Harry Shoell Delta Conic hull design have a fairly flat fuel burn curve. From 2400 RPM to 3200 RPM we increase 7.6 knots from 14.3 kts to 22.9 kts with an increased burn of only 0.11 gallons for both engines.
4. While matching the boost pressure did get me close, (as in item #3 above) it appears that matching the actual fuel burn between the engines makes a significant difference in total overall efficiency. For example, an increase in speed from 17.1 kts to 22.1 kts with the engines synched to FUEL BURN resulted in an hourly fuel burn increase of only 0.06 gallons for both engines. This data is very significant for trip planning. I could make a run to Key West in as little as 7 hours at 22.1 kts (25.4 mph) (vs. 9 hours) and the additional fuel burn would be a negligible 7.5 gallons. This could mean getting in earlier in the day or avoiding an afternoon thunder shower.
5. Again, keep in mind that until the final (fine) calibration is completed, and the possible change in prop pitch done, the actual burn rate may change, however the incremental rates will not, at least to any great consequence.
Although the data is not all in, at the moment I am satisfied with the decision to move ahead with this install. Knowing what the real burn rate is at any given speed, we can now better plan for a trip and the overall result will be our using the boat more. The additional feature of having baseline data will also alert me to a potential engine or prop problem down the road.
RWS

I used the factory brackets to attach the port side, and fabricated my own brackets for the starboard side. I took my time with the installation and was careful about the placement of the sensors and the pulsation dampeners with regard to not restricting access to any other engine room mechanical components.
The project took two weekends. All the connections are crimped and sealed with heatshrink tubing. Where multiple wires were exposed, I used a flexible plastic split wire loom. I tagged all my wires with a labelmaker as well as identifying the supply and return units for identification. All wiring and additional fuel hoses are mechanically clamped or ty-wrapped as necessary.
Although the final (fine) calibration is not complete, therefore the data collected cannot be relied on as far as actual burn rates are concerned. A fill up of fuel, a decent run and a final fill up will provide the info needed for final calibration. That said, the data collected thus far does tell us where our sweet spots are and what kind of difference exists incrementally.
Once fine calibration is done, we may likely find some fine tuning of propeller pitch will be required as well.
Prior to the repower, I was running counter rotating Crusader 454 engines. I had an Ensign digital tach/sync and a gasoline Floscan which was deadly accurate to within five gallons on every fill up with no calibration.
The Yanmar 6LP Turbodiesel refit engines are NOT counterrotating. The counter rotation is achieved by running one of the 2:1 ratio ZF 63A gears in FWD and the other in reverse. In this case the Port ratio is 2.04:1 and the Starboard ratio is 2.10:1.
This disparity resulted in the inability to sync the engines by tachometers or by engine sound. The engines were synched by matching the boost pressure.
The Floscan installation and data has disclosed several important bits of information that will have an impact on the performance of this vessel. Among them is:
1. Apparently the VDO tachs were over reporting RPM at higher speeds. It appears that the Floscan digital tach are accurate, however this will be verified with a photo tach soon.
2. Assuming the Floscan tach data to be accurate, we will likely decrease our current 20x20 prop pitch somewhat once all the results are in.
3. At cruising speeds, these turbodiesel Yanmar engines in the 10 meter Harry Shoell Delta Conic hull design have a fairly flat fuel burn curve. From 2400 RPM to 3200 RPM we increase 7.6 knots from 14.3 kts to 22.9 kts with an increased burn of only 0.11 gallons for both engines.
4. While matching the boost pressure did get me close, (as in item #3 above) it appears that matching the actual fuel burn between the engines makes a significant difference in total overall efficiency. For example, an increase in speed from 17.1 kts to 22.1 kts with the engines synched to FUEL BURN resulted in an hourly fuel burn increase of only 0.06 gallons for both engines. This data is very significant for trip planning. I could make a run to Key West in as little as 7 hours at 22.1 kts (25.4 mph) (vs. 9 hours) and the additional fuel burn would be a negligible 7.5 gallons. This could mean getting in earlier in the day or avoiding an afternoon thunder shower.
5. Again, keep in mind that until the final (fine) calibration is completed, and the possible change in prop pitch done, the actual burn rate may change, however the incremental rates will not, at least to any great consequence.
Although the data is not all in, at the moment I am satisfied with the decision to move ahead with this install. Knowing what the real burn rate is at any given speed, we can now better plan for a trip and the overall result will be our using the boat more. The additional feature of having baseline data will also alert me to a potential engine or prop problem down the road.
RWS
