Re: T&T: Fuel flow meter
With a Lehman 120, you don't need a fuel flow meter! What you need is a fuel consumption chart.
Just MEASURE your fuel consumption at various RPMs and then make up a table which shows fuel consumption. Without naming brand names, in my experience fuel flow meters are temperamental creatures that are wrong more often as they're right, and an accurately measured fuel consumption chart does the job very nicely, especially with a venerable piece of machinery like a Lehman 120.
An easy way to do it is to plumb a small temporary tank (a 5-gal. white water jog would do nicely) to the engine, and plumb the return line to return unburned fuel to the same temporary tank. Fill the temporary tank with clean, filtered fuel and mark it in one-tenth gallon increments as you fill. Then run the engine under load (i.e., underway) for six minutes starting at, say, 1200 RPMs and measure the fuel used at the end of your six-minute run. Then multiply the fuel used in six minutes times 10 for your GPH rating at 1200 RPM. Next, go up 100 RPMs and do the same. Repeat until your engine won't go any faster. With much less than a day's labor you'll have a table that tells you exactly what you're burning across the whole range of RPMs--and it'll do so at least as accurately as a flow meter and at a lot less expense.
An easier (though perhaps slightly less accurate) way to go may be to call up Bob or Brian Smith at American Diesel in Kilmarnock and ask them for fuel consumption figures for your Lehman. http://www.americandieselcorp.com/
I've been using my own home-brew consumption charts on two Grand Bankses, a Nordic Tug and a Nordhavn for the past 20 years or so. When I finish fueling, I note that I am ALWAYS within five percent of my estimated fuel burn. Who needs a fuel consumption meter anyway?
Just one way to skin this particular cat.
--Milt Baker, Nordhavn 47 Bluewater, Fort Lauderdale
Chuck wrote:
Looking for recommendations for a fuel flow meter for the single 120 Lehman on our MT34. I am not looking for anything that needs to integrate to my systems or run on my computer. Just a system that will show me the fuel flow under whatever RPMs we are running. Simple is better. Thanks, Chuck
Thanks Milt, I will give that some consideration. Chuck
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--- On Sat, 1/3/09, Milt Baker miltbaker@mindspring.com wrote:
From: Milt Baker miltbaker@mindspring.com
Subject: Re: T&T: Fuel flow meter
To: "TrawlerWorld List - Post Message" trawlers-and-trawlering@lists.samurai.com
Date: Saturday, January 3, 2009, 9:24 PM
With a Lehman 120, you don't need a fuel flow meter!
What you need is a fuel consumption chart.
Just MEASURE your fuel consumption at various RPMs and then
make up a table which shows fuel consumption. Without
naming brand names, in my experience fuel flow meters are
temperamental creatures that are wrong more often as
they're right, and an accurately measured fuel
consumption chart does the job very nicely, especially with
a venerable piece of machinery like a Lehman 120.
An easy way to do it is to plumb a small temporary tank (a
5-gal. white water jog would do nicely) to the engine, and
plumb the return line to return unburned fuel to the same
temporary tank. Fill the temporary tank with clean,
filtered fuel and mark it in one-tenth gallon increments as
you fill. Then run the engine under load (i.e., underway)
for six minutes starting at, say, 1200 RPMs and measure the
fuel used at the end of your six-minute run. Then multiply
the fuel used in six minutes times 10 for your GPH rating at
1200 RPM. Next, go up 100 RPMs and do the same. Repeat
until your engine won't go any faster. With much less
than a day's labor you'll have a table that tells
you exactly what you're burning across the whole range
of RPMs--and it'll do so at least as accurately as a
flow meter and at a lot less expense.
An easier (though perhaps slightly less accurate) way to go
may be to call up Bob or Brian Smith at American Diesel in
Kilmarnock and ask them for fuel consumption figures for
your Lehman. http://www.americandieselcorp.com/
I've been using my own home-brew consumption charts on
two Grand Bankses, a Nordic Tug and a Nordhavn for the past
20 years or so. When I finish fueling, I note that I am
ALWAYS within five percent of my estimated fuel burn. Who
needs a fuel consumption meter anyway?
Just one way to skin this particular cat.
--Milt Baker, Nordhavn 47 Bluewater, Fort Lauderdale