Detroit 6V92 DDECs

[solanderi]

Genesis,

If available, could you give me an idea of your fuel consumption vs RPM from your flow scans? Thank you

 

[Genesis]

Well I can tell you what my most common burn rates are....

At idle (~6kts), 600 RPM in gear, I burn right around 3gph (combined) for 2.0nmpg.

At 10kts (1100ish RPM) I burn about 11gph (combined) for 0.9nmpg. I can drop that back a knot and get right around 1.0-1.1nmpg if I want, but usually don't.

At 18kts (1850ish RPM) I burn about 36-40gph (depending on load) for 0.4-0.5nmpg.

I don't run above that for extended periods without REALLY good cause, so I can't give you accurate numbers there (haven't had a reason to run there longer than required to check WOT RPM in a while)

The odd thing is, at 13kts (right around 1400ish) I can stay on plane, but I'm burning right in the area of 24-26gph - so in terms of burn per mile, there's very little fuel consumption advantage to running just out of the hole rather than at normal cruise!

That was a big surprise - I expected that my best fuel economy other than in displacement mode would be at "low cruise." Nope! If you're going to come out of the hole you may as well get up and go.

 

[Trojan]

That is a surprise. Do you suppose that holds true for most of us with Hat hulls? About how big of a range in RPM or Speed does that hold true?



BILL

 

[Genesis]

That is a surprise. Do you suppose that holds true for most of us with Hat hulls? About how big of a range in RPM or Speed does that hold true?

From about 1400-1500 RPM all the way up to right around 2000!

Basically from where I can hold it on plane with full tabs (about 13kts) up to high cruise at 1950ish (20kts) - beyond that the sucking sound increases some more.

 

[SKYCHENEY]

Ditto for me too. My boat may weigh more, but it also has a longer waterline. So my 6v92s appear to have about the same burn rate as Genesis, FWIW. I get 1nm/gal at 9knots and .5nm/gal at 16knots.

 

[MikeP]

Just curious - I thought 53MYs all had 8v71s. When did they switch to 6V92s?

 

[SKYCHENEY]

I believe the 1985, 1986, 1987, and 1988 53MY's and ED's all had 92's