Hunter 44DS Cruising Speed

[HarryvdMeer]

To Hunter 44DS owners: what is your typical cruising speed?

My 2004 Hunter 44DS with a Maxprop has a cruising speed of 6.8 knots at 3000 rpm. I believe this is to too low and the prop may not be set correctly.

Here are some details:
Engine: Yanmar 4JH3E 55 hp @ 3800 rpm
Prop: 3 blade Maxprop Easy 18” 18RH-X installed by previous owner
WOT: 4000 rpm plus
Fuel consumption: approx 1 gal/hr

My boat is quite heavy loaded since we are live-aboards, but I still have a good inch of antifouling above water line.

I typically cruise at 3000 rpm. Is this to high?

Your help and input is much appreciated.

Harry

 

[jssailem]

Harry, when you are under power on a flat calm surface how does your boat sit in the water. Does it feel on the level driving through the water or does the boat feel dragged down at the stern. Bow riding high.

 

[Don S/V ILLusion]

My 2004 Hunter 44DS with a Maxprop has a cruising speed of 6.8 knots at 3000 rpm. I believe this is to too low and the prop may not be set correctly.

If this is of any interest, we used to have a 40.5 with the same engine and prop. Made 7 knots at 2500 RPM.

My wild guess is your prop pitch is too low if WOT is 4000 RPM.

 

[HarryvdMeer]

Harry, when you are under power on a flat calm surface how does your boat sit in the water. Does it feel on the level driving through the water or does the boat feel dragged down at the stern. Bow riding high.

Thanks John - the boat seems level.

 

[jssailem]

Hey Harry
Looking at Hunters in the Sailboat data site to find the theoretical hull speed. I learned then 44DS has undergone a series of modifications. It is said to share a hull with the 45CC

Calculations of Hull Speed
Hull Speed10.5 kn
Classic: 8.39 kn

So with the proper prop set, a clean hull, and a fully functional auxiliary or sails and a strong breeze you should mathematically attain better speeds from your boat.

 

[HarryvdMeer]

You are correct John. With good breeze I have comfortably achieved 8.5 kts under sail.

 

[MFD]

The old rule of thumb is the square root of (1.34 x LWL); LWL => length of waterline; for hull speed.
I have a Hunter 41DS with a Yanmar 4JH4AE (54hp); max power at 3000rpm.
Typically cruise at ~7 knots on flat water with light winds at about ~2400rpm and knot meter will show 8kn at 2800rpm which is over hull speed and fuel consumption goes up dramatically, although I do that from time to time to better exercise the Yanmar.

Rarely get over 2800rpm unless fighting choppy seas/winds in some kind sketchy situation.

I have the factory installed fixed 3-blade propeller.

My guess is that the Maxprop you have may not have been matched properly for the boat/engine. Only an idea, could be other things too.

Also got curious and found these charts on your 4JH3E - http://simplicity-marine.com/pdf/Yanmar/JH.pdf
My 4JH4AE has a substantially different power curve and (have not tested) governor probably kicks in at 3200rpm.

 

[RoyS]

Next haul out adjust your maxprop pitch up one notch. Trial and error works for this setting. When you have too much pitch you will not be able to reach full engine RPM. If you get to that setting where you cannot reach full engine RPM then back off one notch. May take several seasons to get the right pitch setting for your boat. Took me three seasons. Sailors should never be in a hurry anyway; leave that to the power boaters.

 

[HarryvdMeer]

Thank you! The pdf is a great find!

 

[HarryvdMeer]

Next haul out adjust your maxprop pitch up one notch. Trial and error works for this setting. When you have too much pitch you will not be able to reach full engine RPM. If you get to that setting where you cannot reach full engine RPM then back off one notch. May take several seasons to get the right pitch setting for your boat. Took me three seasons. Sailors should never be in a hurry anyway; leave that to the power boaters.

You are so right! Want to make sure my yanny is in a comfortable groove.