fastjeff
Gold Medal Contributor
This one has me guessing. Been messing with engines for half a century, and I'm totally baffled.
Marinette 32 footer with twin Mopar 360 V-8s. Port motor has a Flo Scan device that monitors fuel consumption. (I'm too cheap to buy another sensor for the starboard engine.) Going along in rough seas last week, at 2,500 rpms cruise speed, I watched the fuel usage rate CONSISTENTLY increase from 9 gph to 10 as the boat slowed down (from climbing a wave). After the wave passed, however, the rpms came back up to 2,500 and the fuel usage returned to 9 gph. And it did this consistently for hours.
1. The carb is NOT flooding--that I know for certain, both from exhaust sound and feel.
2. The boat climbing the waves was gentle--like smoothly encountering a change in the hill your car is going up.
3. The throttle is fixed in position at that rpm and wasn't moving on its own.
To me, the fuel consumption should have dropped as the rpms dropped, for less intake strokes per minute were occurring, but it went UP! And it did this consistently for over an hour.
Anyone have an explanation?
Jeff
Marinette 32 footer with twin Mopar 360 V-8s. Port motor has a Flo Scan device that monitors fuel consumption. (I'm too cheap to buy another sensor for the starboard engine.) Going along in rough seas last week, at 2,500 rpms cruise speed, I watched the fuel usage rate CONSISTENTLY increase from 9 gph to 10 as the boat slowed down (from climbing a wave). After the wave passed, however, the rpms came back up to 2,500 and the fuel usage returned to 9 gph. And it did this consistently for hours.
1. The carb is NOT flooding--that I know for certain, both from exhaust sound and feel.
2. The boat climbing the waves was gentle--like smoothly encountering a change in the hill your car is going up.
3. The throttle is fixed in position at that rpm and wasn't moving on its own.
To me, the fuel consumption should have dropped as the rpms dropped, for less intake strokes per minute were occurring, but it went UP! And it did this consistently for over an hour.
Anyone have an explanation?
Jeff