35 performance

[gil]

I have a 35 with the 540 cummins. I keep on seeing and hearing about 30kt cruises, but have to push the RPM's up to 2400 and burn over 40 gallons an hour to get the same. Wondering what everyone else is getting with speed, rpm and fuel consumption?

Also have not seen 35 knt top end yet!

[carline]

with 480's, 27-28kt @ 2400, 32 max, no tower, fully loaded
I believe 35's with tower run better because the tower foil lifts the boat

[Calypso]

Would be interested in hearing input as well...am hearing 30-32kt cruise (34 high cruise) with the 540s, tower, etc.

Rick

[isptfish]

This is a very timely topic for me, I am looking at the CC 35 vs the 36 Albie.

I know the performance numbers for the Albie are based on a stripped boat and are not real world. I always assume that all manufacturers numbers are best case scenerios. Therefore real world experience is very valueable. At 2400 rpm on the cummins 540 is that at high cruise? What is top rpm? What load on boat, with or without tower.

Any and all input is appreciated, I have owned Albie's for 15 years and this will be my last boat so making the most informed decision is the key. I've noted from both the Albie forum and the CC forum that there's no place better to get the real info than from those that own the boats. Thanks and Happy New Year!

[Tswann]

On a 2006 35 with tower and the 540s that a friend of ours has and I run on frequently, we see a 27/28 knot loaded cruise at 2150 burning about 37 gph (load hovers around the 80% range depending on what the see conditions are). This is an offshore load (full fuel, water a tackle shop on board and 4 guys) with a clean bottom and clean wheels. This is our every day cruise and where we feel this 35 likes to run, conditions permitting . . .

High cruise at 2400 on the boat is 32 knots under the same conditions, but the economy is not pleasant (can't recall the exact number and I won't guess . . .). To see a 30 knot cruise we are at 2250+ and are burning around 40 gph. At WOT (2600 approx, but Q series Cummins are more accurately spoken about in terms of load, which in this case is 96% or so) we are seeing ~35 . . . fuel burn = lots and lots . . .

Bear in mind that this boat is run typically with no tab, clean wheels (growth on the wheels really can beat the tar out of your efficiency) and a clean bottom, 70 degree water on a warm September day (last time we went offshore), and of course not pushing through big water . . . . You are in Islamorada so the evirnoment will work against you -- growth, water temps . . .

There are a lot of variables that can effect your speeds and burns, and typically several small variances in running preferences, cleanliness, ambient temps, loads/gear on board, etc can bleed a bit of speed/efficiency here and there, and that starts to add up.

With the QSC540s you are developing virtually all of your power/torque/efficiency at about 2200 rpm - anything over that and your are just turning rpms --- i.e. the increase in hp is not at all efficient in relation to the amount of fuel running through the motor . . .

Hope this helps a little . . .

[gil]

those numbers are right on. The boat is an 06 with marlin tower and 27-28 fully loaded for offshore is where the cruise on this boat is and I have not been able to get the 35 knots- in reality I have only tried 2x and we were fully loaded so that may explain it. If "cruise" is where the boat runs most efficiently, cruise is definetly 27/28 not 30. Still good speed as most boat manufacturers stretch the truth and few have true 30 knt cruises. I usually run right below 2200 (close to 29 knots) as this is the sweet spot and where I get the most efficiciency.

Great response, thanks for the insight.

[Tswann]

Glad the info helped. Mac does state that the efficient cruise of the boat is right where you have found it by trial and error and will tell you what the cruise (or high cruise) is as per the various engine mfrs rated specs/throttle settings . . .

The confusion tends to come from the engine manufacturers that rate their engines at a 'cruise rpm of 200 off rated' as in the case with Cummins. This number is the rpm level at which the manufacturers market from, but this number is in a vacuum -- i.e. no regard for fuel consumption, efficiency, etc.

Tight lines . . .

[CClassic28]

Great info guys!! This is what this forum is all about, keep it coming.

Chris