Cruising revs?

[EdHouston]

Hi all

I have as most will know by now Hull #110 365 Ketch.

My question is regarding the correct or best cruising revs for the W40, the notes in all the paperwork I have with the boat states the cruising revs to be 2200rpm. I am bearly pushing 4.5 knots at this rpm in reading the W40 manual cannot find any recomendation as to operating revs but there is a note that the W40 output Horse Power is 37 at 3000rpm.

So all that said what revs do you all run your engines at?

Ed (need for speed)
S/V "Moonlight Mile"

[captsandy]

Sounds like you dont have enough pitch in your prop. Make sure that the bottom and running gear are clean. Then establish what the max engine rpm is in neutral. Just run it up quickly. Then take the boat out and see what the max engine rpm is loaded, in gear. The delta should be 200 to 250 if your prop is pitched right.
     S

[EdHouston]

Hi Sandy

Thanks for the info, I ran the test last night ans the delta was 200, max revs no load were 3600 under laod 3800. I am getting about 4.8 knots at 2200rpm bottom is clean.

Any other ideas or are my expectations too high?

Ed
S/V "Moonlight Mile"

[Higgins]

Any chance your transmission is slipping?

[EdHouston]

Its a brand new transmission so I would hope not.

What speeds are mormal at 2200rpm?

Ed
Moonlight Mile

[Dale Tanski]

When I first launched we could turn 6 1/4 kts at 25-2600.  By the end of the season in fresh water 4 1/2 kts.  The only change was the growth on the bottom.  The paint was dead but we launched anyway as I did not have time for a scrape down.  It doesn't take much to slow you down...
Good sailing...  Dale Tanski

[EdHouston]

Dale

Are you running at 25 -2600 rpm constantly as cruising revs?

I do not want to over rev the engine so was keeping my revs at 2200 if I bump it up to 25- 2600 my issue maybe a non issue.

Ed
Moonlihgt Mile

[captsandy]

Your max revs with no load are high for a w 40. Normal around 28 to 30. Also the revs loaded should be lower than no load revs. A typo? Your tack may be reading high. You can check that with a portable strobe tack. Most mechanics have one. Since the transmission is a 1:1 you can read it at the shaft coupling. Good Luck.
     S

[captsandy]

Ed, Also, most 365s make 6 and change at 22 with a clean bottom and running gear. You may want to ask your diver to read the prop dia and pitch stamped on the hub of the prop.
    S

[EdHouston]

Ok Guys thanks for all your help with this issue .

Little more info for you all.

The injector pump is brand new.
The transmission is brand new.
All filters are new oil and both fuel.
Bottom was clean at last haul out month and half ago and 1000 miles of offshore sailing.
No noticable smoke. (some soot on transom after ten days at sea running engine for about fifty hours charging batteries and propulsion etc)
Replaced oil cooler heat exchanger upon return had one tube leak oil into raw water exhaust discharge.

All temps & pressures nominal.

Max revs in neutral 3800rpm, max revs under load 3600rpm.

My last post was a typo, I will have the tach tested to make sure it is accurate maybe my 2200 is only about 1700 which would make all the sense in the world.

[Dale Tanski]

Ed,
Sorry for the delay...
That 6+ number was for flank speed.  When we settle her down she turns around 5+ at 2100/2200.
Dale

[EdHouston]

OK All

First and foremost once again thanks for all your input on this issue, my tach was reading about 400rpm high, I have a buddy who owns a strobe tach and I found at 1100rpm boat tach the revs were actually only 726.4 yes this thing was accurate to one tenth of a rev, anyhow I adjusted the boat tach and it now matches the strobe as close as I can get it and or need it. I did not do an open water test yet but feel sure I will now push much better speeds.

I replaced my oil pressure gauge and sender and that problem is now a none issue also, next is the engine temp gauge and sender. I did learn if you replace a gauge go ahead and replace the sensor also.

Ed
S/V Moonlight Mile

[SV THIRD DAY]

$50 from Harbor Freight

We have one on THIRD DAY and it's quite handy.

[Lon]

Rich,

That is a great price. Do you feel that it is pretty accurate? I just rented on for $30.00.  I would purchase one if it is easy to use and acurate.  You are right great to have on hand. Thank you for the heads up.

Lon

[SV THIRD DAY]

It was within 10 RPM when I compared it to my engine Tach.  I bought it for my watermaker/generator installation, which doesn't have a tach at this point.  It appeard to be accurate and very easy to use.