*I'm deficient:*get "nose bleeds" traveling on a boat*going faster than hull speed (when I'm paying for the fuel.)Budds Outlet wrote:
I know, I'm not a trawler but... 3,150 produces 24-25kts. That's where the engine sounds and feels the best. Anything more and the secondaries open and so does the wallet!
*Mark, you just have a little touch of "dollar separation anxiety". *A little spending therapy will help you get over it. *As a matter of fact if you will send me your credit card info, I'll help you.markpierce wrote:
*I'm deficient:*get "nose bleeds" traveling on a boat*going faster than hull speed (when I'm paying for the fuel.)
*Kevin, your low speed numbers are very good.ksanders wrote:
In our 4788 Bayliner with 330 cummins...
We get 1.7 NMPG at 7.8 knots
If we slow down to 6.8 knots we get 2.7 nmpg
If we speed up to 15 knots we drop to .68 nmpg
We think thats pretty good for this size boat.
*Same transmission ratio?healhustler wrote:
I'm still working with my own early numbers, but the PO has one of those plastic stick labels next to the tach that says "best cruise 2600", and that comes out to a restful 7.5 knots turning a 22 X 13 prop "or so it is marked". This boat was re-powered with a 140 Yanmar over the original 90 Volvo, but they kept the same prop. Since the Volvos seem to be most comfortable at 6.5 knots, I have not been able to figure out why this boat has turned into a more comfortable 7.5 knot cruiser. Fuel consumption seems to be about the same too. It's possible that when the Yanmar was installed, they re-pitched the old prop too, but I haven't had any reason to pull the boat and check. Regardless, three sources record a silky smooth 7.5 knots at 2600 and 2.2 GPH. It drops to 1.65 GPH at 6.5 but doesn't feel a smooth. 3600 WOT gets 9.5 knots with a pronounced squat.
*Gotta save up for those inevitable yard bills.Moonstruck wrote:
*Mark, you just have a little touch of "dollar separation anxiety". *A little spending therapy will help you get over it.
*In the ICW, going by an inlet coming in from the side is interesting. *You can have a 2 knot current pushing you when you get to it. *As you pass it you may have to deal with a 2 knot head current. *That is a 4 knot change in speed. *In a slow boat it can feel like hitting a wall.rwidman wrote:
Since I'm in the Atlantic ICW, based out of Charleston, SC, I'm dealing with tidal currents most of the time. 2K RPM gives me about 7 knots at slack current, but over land, I'm making anywhere from 5 to 9 knots, depending on the tidal current. And this speed can change rather quickly when passing an inlet.
Most of the time, this speed is fine, but there are some long, boring areas where I'm tempted to step it up a little.
*Kevin, your low speed numbers are very good.timjet wrote:ksanders wrote:
In our 4788 Bayliner with 330 cummins...
We get 1.7 NMPG at 7.8 knots
If we slow down to 6.8 knots we get 2.7 nmpg
If we speed up to 15 knots we drop to .68 nmpg
We think thats pretty good for this size boat.
*Also dripless packings...they need a water feed crossover for single engine ops (at least a*PSS does)FF wrote:
"I havn't tried single engine running."
Check with the transmission mfg before you do, many can not be trailed , the prop must be stopped.
A prop brake frequently requires the shaft to be removed to be installed .