Albin 31TE Cummins 6CTA 450hp - Speed/prop size ?

[lawrento]

Hello AlbinOwners,
I'm learning ....
Wish to seek informations on Albin 31TE Cummins 6CTA 450hp performances.
The engine is currently couple to a IRM 280A '1.75:!.0' transmission.
The speed I'm getting is about 13-15 knots @ cruising speed 2200rpm with 5pax & full fuel tank .... Normal ? And 2400rpm getting 16-18 knots ?
I wish to know what Propeller size other 31TE Owners are using ? Or I'm having the wrong transmission ?
It puzzle me, as I read thru Yachtworld ads .... Albin 31TE with same engine specs are getting 18 knots for cruising and Top speed at 22 knots.
Appreciate your experiences .
Cheers !
Lawrento

[RockHall]

Hi Lawrento
We have a 2004 31TE wither the Cummins 450 with a zf trans. I don't know what prop is on it but plan to take it to a prop shop in md this winter. We get 18kt cruise (2200 rpm) and 22kt wot (2350 rpm) on less than half tank on a calm day with a clean hull etc. your numbers sound off. You should do better.

[lawrento]

Hello Rockhall,
Thanks for your valuable Feed Back, confirmed I need to investigate further into Prop size & Gear ratio ?
Wish AlbinOwners have details to compare ... for improvement plan.
Cheers !
Lawrento
Albin 31TE
RSYC marina
Singapore.

[lawrento]

Hello Albin 31TE Owners,
Updates ....
Last weekend able to take a look at the 31TE Propeller section, measure the Prop Diameter = 22ins.
Unable to find any other infos for the Pitch size ....
Wish 31TEOwners can help on the Pitch size infos of your boat ....
Cheers !
Lawrento
Albin 31TE, Y1996
RSYC
Singapore.

[Tuxedo]

Lawrento -

I want to say the prop on Tuxedo was a 22 x 24 4 blade, but I no longer have the paperwork. What I do know is that you should be able to turn well over at least 2,650 rpm (2,700 would be better) fully loaded, so you should have your prop adjusted to achieve that.

If you do, you can cruise all day long at 2,400 rpm @ 18 - 19 knots. Here's some proof

[lawrento]

Hello Tom,
Another valuable contribution of experiences .... Looks like I may not have in place a wrong prop.... need to confirm my pitch size first, before proceeding to others.
Thanks !
Lawrento
Albin 31TE
RSYC
Singapore.

[lawrento]

Hello 31TEOwners,
Last wkend took my 31TE out with 1/4 Tank and 6 pax.
At top speed of 2550 rpm achieve 19.9 knots with following current about 1 knot.
At normal speed of 2400 rpm achieve 16.5 to 17.2 knots with following current as above.
Prop size: 22ins diameter with unknown pitch condition..... my boat is anti-foul and on dry berth all the time.
What do you think ?
Wish to hear more experiences ?
Thanks,
Lawrento
Albin 31TE
RSYC
Singapore.

[lawrento]

FYI and Updates .....
Took out my propeller and send to prop shop for analysis ....
Now I understand my props issue ... Diameter 22ins x Pitch of 27, no wonder cannot achieve normal performances.
Currently my albin is fixed with a temporary prop of 22.5 x22.5, produce 17 kn/2400rpm and 19.9 kn/2600rpm against current.... better than previous result.
Will be trying out next prop size 24 x 23 with Light cupping.
Hope to see better performances in South East Asia Waters !
Cheers !
Lawrento
Best Bet 3
Albin 31TE
RSYC
Singapore.

[Russell]

I do not see why you are going from a 22 inch diameter to a 24. You are overpropped now and the increase in diameter may give you even more problems. When I had to change my transmission to one of a different ratio my mechanic tried a larger diameter prop on my boat because he had it in the shop and it caused such hull vibrations that he had to remove it and go back to one of the original diamter. If your present prop cannot be reduced in pitch from 27 to 24 you should purchase one with the original diameter of 22 inches.

[jointventure]

Our 31 with the same engine and transmission has a 24 x 24 cupped prop (original with boat, 2001 ). At 2600 rpm max rating we attain 21-22 knots at 2400 ,18 knots . Now for cost of fuel considerations we run at 2050 for 12-13 knots.

[lawrento]

Thanks Russ for your bigger diameter propeller design/weight concerns... I will tweat my current prop 22x27 to 22x26 and keep as spare prop.
Thanks John for your valuable propeller datas input..... this is the target, I wish to achieve.
Cheers !
Lawrento
Best bet 3
31TE 1996
RSYC
Singapore

[lawrento]

Hi Albin31TEOwners,
FYI and Updates .....
Gotten my local made new propeller cupped 24x23, here's the sea trial result;-
Against current, about 1+knot, 2050rpm - 14.5+kn. 2300rpm - 17.5kn. 2400rpm 18+kn.
Following current, about 1knot, 2300rpm - 18+kn, 2400rpm 20+kn.
However, Top speed at 2500rpm - 21+kn.
No abnormal vibration or other occurrence and sea state 1-2 footers ride ...
What do You think ?
Cheers !
Lawrento
Best Bet 3
Albin 31TE
RSYC
Singapore.

[Russell]

The most important number to indicate that you have the right prop is that you can hit 100 RPM over the rated horse power RPM. If 2500 is the maximum you can do you are overpropped. Read the attached file from boat diesel.