48 Sundancer Engine Loading

[Garry]

I have a 2006 48 Sundancer with twin Cummins QSC's. When working the throttles up to WOT, which is 2650 rpm the engine loading is close to equal until the boat is on plane. Once the boat reaches a plane around 2000 rpm the port engine loading drops from 65% to 45% loading, while the starboard engine would remain close to 65%. The loading differential of 20% remains close to constant until around 2525 rpm when the differential becomes less then finally the same, 99% at 2650 rpm. The starboard engine fuel consumption is 33% higher due to the higher engine loading. I had a Cummins mechanic on board to verify exhaust gas temperatures, boost pressure, transmissions etc. and they are working within spec. with no faults.

Anyone experienced this issue and what did you do to correct the situation.

Thanks for your replies,

Garry

 

[douglee25]

That's interesting. What do they use to measure loading?

Doug

 

[missnmountains]

Ours is almost exactly the same difference as yours. The starboard engine runs 1 GPH higher when at cruise (2300RPM). I had our mechanic look at it and he said not to worry. At every fill up, the amount of fuel I put in confirms the difference. The loads are about 5% higher on the starboard at cruise.

BTW, we have had a 10 PSI difference in oil pressure since day one at cruise (even at idle). Again, the Cummins South mechanic said that was within normal specs.

Ken

 

[earthmover17]

This is not apples to apples but my Starboard engine always runs slightly harder as the power steering pump is on that engine. It's the only thing I could figure out for the difference.

Jack