CD30 MKll Westebeke engine

[Paul Skudell]

My CD30 mk ll is equipped with a 30 hp Westebeke matched to a MAX PROP (3 blade) I do not think that the boat is moving well relative to that size engine. 2750 rpm gets me 6 knots. Into stong wind and I am lucky to get 4. Is this is as good as it gets? I'm thinking of taking the pitch up a notch but would like to know if anyone out there has an opinion. Thanks, Paul Skydell s/v TRAVELER



ps30fg@optonline.net

[steve]

Man, you should be water skiing behind that 30.

My CD30 mk ll is equipped with a 30 hp Westebeke matched to a MAX PROP (3 blade) I do not think that the boat is moving well relative to that size engine. 2750 rpm gets me 6 knots. Into stong wind and I am lucky to get 4. Is this is as good as it gets? I'm thinking of taking the pitch up a notch but would like to know if anyone out there has an opinion. Thanks, Paul Skydell s/v TRAVELER

[Michael Heintz]

6 knots.... lucky you !!!!!
I've got the westerbeeke 21A in my cd 30 MKII, we do about 4.6 knots at 2100 rpm. Man I would like to have the 30hp

"Macht Nichts" hull 004



mzenith@aol.com

[Larry DeMers]

There is something wrong with your powertrain. Either the pitch is too aggressive, or too weak..or, you have installed a 14 in. prop in the aperture made for a 13 in. prop, messing up the water flow into
the prop. I say this last part because;
a. The standard prop for the CD30c is a 13in two blade. The aperture for the prop is made for that size prop.

b.Maxprop makes 14 in. and larger props, so I assume that the prop is their smallest offered, at 14in.

By comparison, I get 5.3kts at 2050 rpm (using the 13HP Volvo MD7B), and 6 kts. at 2200. My redline is 2600 rpm.

With the horsepower you have, that boat should be able to reach 5 kts. easily..certainly 6 kts. with a little extra power.

Those of you that are seeing lower kts.indicated for the rpm being cranked out, I would advise doing a calibration check of the speedo first off. That could be indicating a low reading, which is easily fixed. THe MD7A/B's should be able to give you around 5 kts at ~2000 rpm. If you are far from these figures, then there is a problem somewhere.

My CD30 mk ll is equipped with a 30 hp Westebeke matched to a MAX PROP (3 blade) I do not think that the boat is moving well relative to that size engine. 2750 rpm gets me 6 knots. Into stong wind and I am lucky to get 4. Is this is as good as it gets? I'm thinking of taking the pitch up a notch but would like to know if anyone out there has an opinion. Thanks, Paul Skydell s/v TRAVELER

[Catherine Monaghan]

Hmmm, we've got a Westerbeke 21A in our CD32 and she cruises at 6.4 knots at 2200 RPMs. (According to the operator's manual for this engine, 2200 is the optimum cruising RPMs). We also have a 3-bladed fixed prop. I wonder if the wider beam of the CD30MKII has anything to do with the cruising speed? The CD32 displaces 11750 lbs compared to the MKIIs 10500 lbs so you'd think the CD32 would be slower with the same engine. More food for thought.

catherine_monaghan@merck.com
CD32 <a href="http://www.hometown.aol.com/bcomet/real ... ization</a>, #3
Rahway, NJ
Raritan Bay

6 knots.... lucky you !!!!!
I've got the westerbeeke 21A in my cd 30 MKII, we do about 4.6 knots at 2100 rpm. Man I would like to have the 30hp

"Macht Nichts" hull 004

catherine_monaghan@merck.com

[Bob Loewenstein]

Hmmm, we've got a Westerbeke 21A in our CD32 and she cruises at 6.4 knots at 2200 RPMs.

Hmmmm, we've also got a Westerbeke 21A in our CD32 and she cruises at 5.6 knots at 2200 RPM. We're usually towing a hard dinghy behind, though.

We also have a fixed 3 blade prop. I have not seen hull speed even with a clean hull and no towed dinghy.

Bob



rfl@yerkes.uchicago.edu

[Catherine Monaghan]

Double hmmm.

Can towing a dingy make that much of a difference? On our trip to the rendezvous in New England we travelled with Dick Feffer (Adamarie, CD30MKII, same engine). He was towing an inflatable. He radioed us to ask if we had turned on our afterburners because he couldn't keep up. We blamed it on his 2-blade prop and the dingy.

Our engine was rebuilt in 1996 so maybe she's running more efficiently now. We also paint our prop with Petit's antifouling paint for metal. A barnacle-free prop makes a big difference in performance.

I don't know what else could cause such discrepancies.


Cathy

Hmmm, we've got a Westerbeke 21A in our CD32 and she cruises at 6.4 knots at 2200 RPMs.

Hmmmm, we've also got a Westerbeke 21A in our CD32 and she cruises at 5.6 knots at 2200 RPM. We're usually towing a hard dinghy behind, though.

We also have a fixed 3 blade prop. I have not seen hull speed even with a clean hull and no towed dinghy.

Bob

catherine_monaghan@merck.com

[Bob Loewenstein]

A barnacle-free prop makes a big difference in performance.

I agree. Our prop was barnacle free (due to my having dived and cleaned it off). When the boat was surveyed, the pitch was measured and deemed ok. I suppose I could check the pitch myself. Catherine, what are your pitch and prop size?

The engine has good compression, so I assume it performs well. It has about 1300 hours on it.

Also I know the knotmeter is correct to within about 5% or so.



rfl@yerkes.uchicago.edu

[Catherine Monaghan]

Bob,

I'm not sure of the prop size or pitch, that may have to wait until the boat is hauled in the Fall -- hopefully I'll remember.

If the weather cooperates, we'll take Realization out this weekend and make a run between lighthouses on the bay and check the knotmeter and knot log, but based on our recent trip to Niantic Bay the instruments seemed pretty accurate -- we ended up where we were supposed to, when we were supposed to. I'll also recheck the speed at 2200 RPMs.

Also, we've been burning bio-diesel (soy). Do you think that could make a difference as well?

Cathy

A barnacle-free prop makes a big difference in performance.

I agree. Our prop was barnacle free (due to my having dived and cleaned it off). When the boat was surveyed, the pitch was measured and deemed ok. I suppose I could check the pitch myself. Catherine, what are your pitch and prop size?

The engine has good compression, so I assume it performs well. It has about 1300 hours on it.

Also I know the knotmeter is correct to within about 5% or so.

catherine_monaghan@merck.com