Smartcraft sync or engine issue?

[JV II]

Since I took ownership of the boat in April, I noticed the port engine has about 10 hours more than the starboard engine. Also, the load and fuel burn is higher at the same RPM on the port side. At 2250 RPM, the port engine burns .5 GPH more than starboard and runs at 80% load while the starboard is at 77%. Both engines read the same throttle position, 80% (with sync on, I did not test with sync off). Engine temps, oil pressure, and volts vary at an insignificant difference. The boat goes straight at 0 deg rudder. Both engines will run up to almost 2600 RPM (with sync on). Is this a Smartcraft calibration issue? I have to look at the transmission temps again. I think one was running a little higher than the other. May have been port, but still within 20 degrees of the other. The oil in both transmissions is amber and no foaming.

 

[Henry Boyd]

Smartcraft is not actually measuring the fuel being consumed unlike systems like floscan that meter the an mount of fuel that passes through the measuring device. It calculates fuel consumption based on rpm, injection duration, engine displacement etc. The potential flaw is the assumption of how much fuel is being passed through the injector nozzle for a given set of conditions. Since that assumption is based on the OEM spec, injectors with a couple hundred hours on them may not be performing quite the same. That being said the injectors are most likely operating within the window of acceptable conditions. This would lead to discrepancies between fuel said to be consumed and fuel actually consumed. On our gas 496 SC is usually off in that we consistently need a few additional gallons to reach full than SC reports.

I have also noticed small discrepancies with engine temperature and system voltages. For the purpose SC is provided; driver monitoring, it is probably accurate enough. However, if you are going to try and do diagnostic type work you may need to use more accurate tools

Henry

 

[jff]

I don't have any specific numbers written down (I owned a 2005 48DA for three years) but I know that I had similar readings, the burn showing on the SC was never identical (although I think in my case it was more like .2 off) and none of the other numbers ever match exactly either. Engine temps were typically within 5 degrees of each other. In general, two different motors just aren't going to perform identically and as the previous poster pointed out some of the info on the SC is calculated and not measured. I'm not a mechanic but my opinion is that the answer to your post is neither - ie. I don't think you have a SmartCraft or an engine issue. For what it's worth ...