6-71TIB's adding Maretron Flow meters

I have the same engines and have been itching to install the maretrons but I have never been able to get maretron to commit to the flow rates those Detroit's use. The sender's I believe have 5/16" orifices while the supply lines are 5/8".. Remember it's not the 30 - 40 gph that the engine consumes , it's the gross flow that they produce.

That being said, I really hope you get positive advice.

Yes that was my problem, I asked if they had a 6-71 in their list of completed projects and they didn't, or so they said.
I know of people with similar HP that have done it but when I looked at the engine it didn't circulate as many gph as the DD.

how much?

????

Don't you need a meter on supply and return and then read the difference for DD's ?

Yes you do as on any diesel engine.

With 6-71s, I believe maretron meters don't match well. With the smaller one the top flow is not great enough to handle higher RPMs but the larger one doesn't handle the lower end.

As an example if I want to monitor hull speed fuel consumption you need to get down to the 1/2 gph range that the small one provides but it doesn't handle flow levels at cruising speed while the larger one handles the cruise volume it doesn't read below 6 gph so doesn't work for the hull speed range.
On my Viking I typically burn about 2gph per engine at hull speed. Hence the problem.

Which meters did you purchase?
One person I know with 450hp Yanmar's used a large for supply and a small for return.

Keep me posted on your progress.

At slow speed, your Detroits are still moving over 20+ GPH in fuel.
Consumption is the difference between the in & out senders.
My flow scans with 5/8 & 1/2 lines (3/4" senders) read 1/10gph fairly well on 12V71TIs. AND at idle.
I'd go for the largest sized sender available for supply, maybe, maybe the next size down for returns if that would work.
The fuel out flow restrictor at the head is about .050". There is not a lot of pressure or flow on the return.

I agree with you but the larger M2 meters have minimum range of 6gph. I asked Maretron a couple of years ago if I used those meters could I measure net flow down in the 2-4gph range and they wouldn't provide a definitive answer. They basically won't or can't commit to any design specs.

1) Pretty sad but sadly typical of a web sales group not to have proven answers per applications of some gizmo they are trying to sell. All they know is in the manuals.

2) If I was desperate enough to use these devices, I would size the senders to match the pipe fittings nearest the engines. Including different sizes for in/out.

3) There are K factors involved during the installation. A good sign of some precision of operation. Some days we get lucky and it works.

That's what I thought I would do as well, until I determined that the Maretron fitting is half the size of the DD engines fuel lines.

From 1/4 to 1 inch senders? What Maretrom fitting are you referring to?"

Description
Fuel Flow Sensor - 25-500 LPH/6.6-132 GPHFeatures:Operating Temperature: -40°C to 80°C (-40°F to 176°F)Storage Temperature: -65°C to 170°C (-85°F to 338°F)Port Size: 1/4 NPT FemaleCable Length: 1M (3.28 ft)Maximum Viscosity: 1000 cPsPressure: 68.95 Bar (1000 PSI)Strainer Size: 200 Mesh (If not already installed after fuel filter)/li/ul !--- cis:y4w2Om4GJ5A= ---

You'll see above that the description for the MR2 has 1/4" npt port size. My 6-71s have 5/8" supplies and 1/2" returns . Based on my knowledge that's a huge restriction point that I couldn't get over. If Maretron is now providing these with bigger ports then that's a game changer for me