2001 28TE with Cummins 370b max speed

[jetter]

Today I used photo-tach on engine. WOT reads 3000 RPM on Tach, 3038 on photo-tach. Speed 23 knots GPS. I guess I will just live with it. I'm normally cruising at 14 knots. I was pleased to see RPMs that close.

[Misterpilot72]

I don't have a whole lot of experience, but I have the 370 as well and at 3000rpm and 3/4 tank of fuel I can run 27 KNTS exactly.
Not sure on my hull weight though. I had 4 big dudes onboard.

What are the dimensions of the prop and shaft ?[b

[Pitou]

I don't have a whole lot of experience, but I have the 370 as well and at 3000rpm and 3/4 tank of fuel I can run 27 KNTS exactly.
Not sure on my hull weight though. I had 4 big dudes onboard.

What are the dimensions of the prop and shaft ?[b

Shaft size fitted with the Cummins 370 6BTA is 1.5 inches. Prop is dependent upon gear ratio.

[Jaredh]

My 96 with 2 people on board and half fuel in the main tank hits just shy of 28 knots at 3050rpm. Is 11,000 lbs correct? That seems really high. How much stuff are you keeping on board? I try to keep the boat as light ship as possible.

Weight doesn't seem too far off. My 03 Flush Deck (315 yanmar) was 10,200lbs with less than a half tank of fuel, empty water, and empty holding tank on the forklift.

Scales had me at just under 13,000lbs on the trailer (Steel ~2200lbs).

These are not light boats!

[jetter]

Prop is a 19L18. Shaft 1 1/2" as per Pictou

[Pitou]

Prop is a 19L18. Shaft 1 1/2" as per Pictou

With a ZF Hurth 1.4 gear I ran a 19"left X 17 pitch - 4 blade Nibral wheel tuned to class I.

I believe that the cupping was a 3. (mid cup)

[jetter]

Checked today. its a ZF IRM 220V-LD Gear 1.527/1. Interesting that Albin changed the transmission gearing.

[Revtech79]

Hi Jetter,
I recently acquired a 2005 Albin with the 380 qsb Cummins and same 1.527:1 gear. I’m having the same speed issues. I can easily hit 3070 rpm engine sounds like it’s hitting rev limit. But best speed I can get is 23 knots. Cruising speed I have to turn 2550 rpm to barely get 18kts. At a nice 2400rpm I ‘m only doing 15knots. And at that speed the hull doesn’t really like it. Did you get anymore info regarding your prop or setup? I spoke with a well know Albin prop shop and they are telling me it should be a 19 x 23 or 24 pitch prop. Any info will help, I really want to get this boat moving faster.

[RobS]

Revtech,

You have a QSB380 in the 28TE? Great engine but must be a shoehorn of an install... got any pics to share?

You need to start off by plotting your fuel burn throughout the rpms listed on the table on page 1 of this attachment. Plot them to the right of the printed gal/hr at each rpm. As long as your fuel burn does not exceed the printed burn numbers you can run that engine at 2,500-2,600 all day long.. If you fuel burn numbers exceed the printed numbers then you are overpropped and my statement no longer applies.....

[Revtech79]

Hi Rob, Thank you for the info. Yes she has the QSB 380 with 550 hours. I can definitely send some pictures. She’s a little tight but not too bad of access with the floor boxes open. I also charted some fuel burn numbers. The closest I get to the factory numbers is @ 2450 rpm i’m burning 9.8gph, from your chart engine fuel burn calls 10.4 @ 2400 but the boat is barely getting out of the water at that rpm pushing water like a displacement hull 14 to 15 knots. After 2400 the gph numbers are all lower. At full throttle I can easily hit 3080rpm and max fuel burn I can get is 15.5 to 16gph. Engine chart is saying 20.1.
I wish I knew what prop was on it, however I didn’t get the numbers before the boat went in the water and I closed on it. Do you know of anyone with a similar gearbox and engine setup? I love to hear their numbers. Thanks for the help.

[Pitou]

I wish I knew what prop was on it, however I didn’t get the numbers before the boat went in the water and I closed on it.

How about your survey report? The prop description should be noted there.

[Revtech79]

Actually the purchase was a little complicated and I was unable to schedule a full survey in the timeframe needed for the sale.
I did run some more numbers yesterday on my way back from Block. All gph readings are less than Cummins gph chart. Next weekend or so I will put on the dive gear and see if I can get some numbers off the prop.

[RobS]

If those fuel burns you are reporting are indeed “accurate/true”, then yes you are leaving a lot of power on the table.. It's not hurting anything, but if you want her to “get up on top” and stay there easier, Ideal thing to do is to pull the prop and have it properly scanned for dimensions & quality... A POS prop on a hard to plane boat is the same as a FLAT tire on a race car

But, since she's launched and probably not scheduled to come out until Thanksgiving-ish, the other option might be to do your due diligence to ID what's on there now (stamped markings, digging up old records, etc) and then research a new high end prop and what needs to be added - dia, pitch, cup ...... And then keep what you have as a spare.

Of course scanning what you have now is closer to an "exact science"...

[Revtech79]

Thanks Rob, if I can narrow down some definite prop numbers I'm leaning towards ordering a new prop and may do a mid-season swap. I was able to get some pictures of the fuel burns numbers along with my speed. The last one, the digital RPM read out is hitting 3080. Also I've included a few pics of the 28 with the 5.9 QSB.

[Revtech79]

Just an update,
I was able to dive and get the numbers off my current prop.
It's a Michigan 350431 which turns out to be a 19x21. I had Michigan run the numbers for my 380 engine and 1.527 transmission. They came back with a 19x23 with medium #5 cup recommendation. If I can work it out I may do a short haul and change it out. Thanks for the help.