Ford Lehman 80hp fuel consumption at 1000rpm?

[dennisail]

Hello. My friend has a 45 foot ketch with a Ford Lehman 80hp. He replaced it with a stationary engine version as it was blown. The injection pump has weights to suit the stationary engine use and it will only rev to approx 1000rpm when used as propulsion in his yacht. We can almost get 5K out of it which is good enough for now.

We plan to move the boat, but we need to know approximate fuel consumption. How much fuel would you expect the Lehman 80 to use at 1000rpm, obviously the prop will not be absorbing much power at this RPM either.

I was guessing about 3L/h?

Anyone got any ideas?

[banjoship]

I have a Swanson 42, it was powered with a lehman 80hp. My experience, and the boat came with complete engine records from launch in 1980, is fuel consumption of 3.2l per hour at around 1600rpm. That's an average over 7000 hours. I would expect a fair bit less at 1000rpm, maybe 2.8l per hour??
Hope this helps
Lee

[atoll]

i delivered an 80ft barge a while back with a ford dover 4cyl in it and motored mostly at 1200-1400 rpm,and used fairly consistently 6-7 liters per hour,but the barge was 50 tons

[Dockhead]

Originally Posted by dennisail

Hello. My friend has a 45 foot ketch with a Ford Lehman 80hp. He replaced it with a stationary engine version as it was blown. The injection pump has weights to suit the stationary engine use and it will only rev to approx 1000rpm when used as propulsion in his yacht. We can almost get 5K out of it which is good enough for now.

We plan to move the boat, but we need to know approximate fuel consumption. How much fuel would you expect the Lehman 80 to use at 1000rpm, obviously the prop will not be absorbing much power at this RPM either.

I was guessing about 3L/h?

Anyone got any ideas?

Diesel engine fuel consumption depends on power being produced more than RPM. It's impossible to say without knowing how the prop is pitched, mass of the boat, clean or dirty bottom, etc. If that boat is say 12 tons, clean bottom, motoring very slowly, prop not grossly over or under pitched, I would guess 3 or 4 liters an hour, but that's a WAG. It won't be 10, I think you can say more or less for sure, and won't be 2.

[dennisail]

Thanks guys. I was just after ballapark figure. Obviously there are many variables.