do this fuel burn numbers sound right

[lime4x4]

Had the boat to maryland this weekend. Topped off the fuel tank and installed the lowrance fuel flow setup. The boat is a 1986 268 searay weekender. It was pretty well loaded with gear and people probably real close to 8000lbs.At wot 4400 rpm's the fuel gallons per hour was showing 15.89. At 3500 rpm and 23 mph it was showing 13.24 gallons per hour. The engine is a 350 4bbl carb. I'm using a marine approved electric fuel pump. I have the flow sensor installed after the electric fuel pump.The pump is rated for a max pressure of 7psi and 72 gallons per hour fuel flow

 

[winbasic]

Re: do this fuel burn numbers sound right

Had the boat to maryland this weekend. Topped off the fuel tank and installed the lowrance fuel flow setup. The boat is a 1986 268 searay weekender. It was pretty well loaded with gear and people probably real close to 8000lbs.At wot 4400 rpm's the fuel gallons per hour was showing 15.89. At 3500 rpm and 23 mph it was showing 13.24 gallons per hour. The engine is a 350 4bbl carb. I'm using a marine approved electric fuel pump. I have the flow sensor installed after the electric fuel pump.The pump is rated for a max pressure of 7psi and 72 gallons per hour fuel flow

Mate, that sounds pretty thirsty. 'Down Under' I'm running a 28'Mustang with a 350 Volvo Penta with similar weight to what you describe and I'm using about half your fuel - only difference I see if that the VP is EFI compared to your 4bbl but still, sounds like you're burning through more juice than usual.

 

[45Auto]

Re: do this fuel burn numbers sound right

A brand new, fuel injected 350, lightly-loaded Larson 26 (2 people, 1/4 tank, 6500 lb dry) burns about 10.5 GPH at 3500 RPM and 23 MPH. I would say 13.2 is probably about normal for a 22 year old, heavily loaded, carbureted engine. Lightly loaded, fresh tune-up, etc., you would probably be in the 11's.

I'm surprised it was only showing 15.9 at WOT. What was your speed there?

I'm running a 28'Mustang with a 350 Volvo Penta with similar weight to what you describe and I'm using about half your fuel

I would be very interested in seeing verifiable fuel consumption figures on a 28' boat that is capable of better fuel efficiency than 19'-20' boats (6-7 GPH at 23 MPH or so) less than half its weight with the same engine.

 

[tommays]

Re: do this fuel burn numbers sound right

"I have the flow sensor installed after the electric fuel pump.The pump is rated for a max pressure of 7psi and 72 gallons per hour fuel flow"


The fuel flow meter has to be on the suction side of the pump it is NOT supposed to be under pressure

If you have cobbed it on the pressure side of the pump with hose clamps it is very dangerous as it NOT supposed to be under pressure

 

[lime4x4]

Re: do this fuel burn numbers sound right

I will move it to the suction side and get some new numbers. At wot the boat did 30 mph probably could've got more but the bay was starting to kick up some

 

[45Auto]

Re: do this fuel burn numbers sound right

15.9 GPH at 30 MPH with it loaded down sounds like it's running about right. Around 2 MPG is what I would expect from a boat the size of yours.

 

[winbasic]

Re: do this fuel burn numbers sound right

AI would be very interested in seeing verifiable fuel consumption figures on a 28' boat that is capable of better fuel efficiency than 19'-20' boats (6-7 GPH at 23 MPH or so) less than half its weight with the same engine.

I haven't got a flow meter installed so can only go off the distance travelled on the GPS and the amount of fuel I'm throwing into it. I'll have a troll around and see if I can find any verifiable figures but so far the only verification is at the bowser.

 

[paulrfrancisco]

Re: do this fuel burn numbers sound right

I just recently added dual Northstar F210 fuel flow meters on my boat, and while theyre big blocks and a larger boat, it is running about 13.8 & 15.4 at 3300rpms, 27mph... My motors dont seem to consume the same fuel rate... but your numbers seem close.