Performance numbers Yanmar 6lp-ste

[socalmike]

2001 28 te engine box 6lp ste with half tuna tower

Ran the boat over the weekend in the bay to get some performance numbers. 3/4 tank of fuel and full water. i was the only person onboard.

4130 rpm no load
3870 wot under load

2500 rpm 8.6 knots on gps
3000 rpm 12.5
3250 rpm 14.5
3500 rpm 16.5
3870 rpm 19.0

prop is 19x16. (was 19x17 but i was only getting 3815 rpm)

I would like to see how I can gain a few knots especially in the 3000-3250 rpm range. I am not sure how the cup is set on the prop currently. I am having it pulled to be scanned again.

Can cup increase speed while still maintaining rpm?

Thanks

Mike

[Tree]

The simple answer is yes. 19 x 19 with a 5 cup is the usual size. That's using technology from the year 2000. I had a prop developed that is 20.5" x 19.5" and a 3 cup which gives me around 18 knots at 3300 rpm. At WOT about 23 knots.

[Jeremyvmd]

remember that the half tower is going to cost you a few knots as well, one downside of that sort of addition. weight and drag will affect your performance. But honestly with my rear top (and gen/ac) I was getting 21-22 wot with two people on board (with the new motor) and full fuel, so I would imagine you have a little performance to gain there

[MadMoney]

Tree - I'm intrigued by your numbers.... can you share more performance information?

Thanks,

Anthony

[RobS]

....

Can cup increase speed while still maintaining rpm?

Thanks

Mike

With all else being equal, no. Adding cup will increase effective pitch thus increasing load.

[catalina_mike]

My linkage was not set up correctly on my 6LP effecting WOT RPM.

[socalmike]

mike. can you advise what was the issue with it please. Mike

[Tree]

viewtopic.php?f=5&t=8687

my data sheet is an attachment towards the bottom