A mini review of a Campbell Sailor 3-blade prop

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Clark

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Jun 30, 2004
886
Hunter 280 Lake Guntersville, AL
A mini review of a Campbell Sailor 3-blade prop - UPDATED

I had been running a Martec geared folder on our 1996 Hunter 280 since we bought the boat 4 years ago. The prop did what it was designed to do with the limitations exhibited by a folding 2-blade: poor reverse, unpleasant vibrations and excellent (low) drag characteristics. I bought a Capri TR/FK this spring to scratch my racing itch and resolved to make the power side of our Hunter more pleasant.
This morning, I pulled the Martec and installed the Campbell Sailor - 14 x 8 RH for a 1" shaft. My engine is a 2GM20F w/ a Kanzaki KM2P - 2.62 gearing. After launch, we motored out to the channel and started opening the throttle and ran it at 1000, 1500, 2000, 2500, 3000 and 3400 rpm. Ninety percent of the vibrations are gone. I forgot my GPS so I don't have speeds yet but will post those when I go back out. Unfortunately, the little Yanmar smoked quite a bit between 3100-3400 rpm (accelerating all the way) but since the proper running rpm is 2800-2900 rpm, I'll be avoiding those rpm anyway. She really does sing at 2800!
Reverse is very much improved. Prop walk in reverse is apparent but not too bad; something I intend to learn to use. Didn't notice much in forward but I'm sure it is there.
Sadly, we didn't get a chance to sail with the new prop so that'll have to wait for another post.

Fair Winds,
Clark

UPDATE: Ran the boat yesterday and got these averages (2 runs, one against and one with the wind) with a GPS - no current - clean bottom -speed in knots:

RPM -------1st Run ------2nd Run -----Avg.
2000-------- 4.1 -----------4.4 ----------4.2
2500-------- 5.0 -----------5.4 ----------5.2
3000-------- 5.8 -----------6.2 ----------6.0
3500 WOT 6.3 -----------6.7 ----------6.5

yanmarhelp.com states MAX is 3600 and cruise speed should be 2900. Based on that, I may be slightly over-propped. However, calculated hull speed for our boat is somewhere around 6.7 kt so according to that, I am not reaching hull speed even at WOT so does that imply an engine down on HP a bit?

(ugh, tables don't work too well)
 
Last edited:
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Clark:

I would contact West by North and explain to them about the smoking issue. I am sure that they would like to know about this and will take care of the issue. You really do not want to be over-propped. It is good to have that extra push when you "really" need it.
 

Clark

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Jun 30, 2004
886
Hunter 280 Lake Guntersville, AL
Thanks Steve, I'm a little uncertain re: the smoke.

Clark:

I would contact West by North and explain to them about the smoking issue. I am sure that they would like to know about this and will take care of the issue. You really do not want to be over-propped. It is good to have that extra push when you "really" need it.
I'm far from a diesel expert so keep that in mind. The smoke we got was a light blue/gray that got more copious; not black. My understanding is that this is an indication of rings or glazed cylinders, etc. and not of an overloaded engine (black because of too much fuel?). I can reach 3400-3500 so am I over-propped? Not knowing how fast we were going is a variable too. Thoughts?
 
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druid

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Apr 22, 2009
837
Ontario 32 Pender Harbour
I would say the smoking has nothing to do with the prop. Did it smoke with the old prop? Might be it's working harder with the new prop. Anyway, if you can get 3400+ WOT the prop is "just right".

I've gotten that blue-grey smoke at various times, and I don't think it's rings, since I never lost oil. I think it's a less-extreme version of the black smoke, ie incomplete burning of the diesel, caused by insufficient heat (caused by poor compression) or uneven "spray" from the injectors. Try pulling the injectors and getting them tested and/or rebuilt.

EDIT: glad you like your CS! :)

druid
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Clark:

I would still contact Norm. Yes you can be over-propped and still reach the 3400-3600 RPM's. These engines can rev past 4000-4200 rpm (and will not break). The max RPM is controlled by the govenor and not the prop.

I think you will find that Norm will give you an honest opinion.

If you have any doubt about your engine you may want to have an engine survey and get an opinion. These engines are rated at 10k-12k hrs when properly taken care of. You should be running your engine a 70-80% of Max rated (3600) rpms when cruising.

If you idle your engine for prolonged periods of time (30-60 min) you should run it up to 3200-3400 RPM for the same amount to time to prevent cylinder glazing.

If you have any questions about the operation of a Yanmar engine, take a look at Yanmar Help.com They have a lot of information our there by a "certified" Yanmar dealer.
 

Clark

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Jun 30, 2004
886
Hunter 280 Lake Guntersville, AL
Thanks again Steve. I did go to yanmarhelp.com and they state that proper cruising speed (85% full throttle) is 2900 for the GM series. They do defer to the engine data plate for Max Rated RPM and then refer to a maximum loaded rpm for the GM series to be 3550-3650. I have suspected an engine issue for a while since I believe I've always made this light blue/gray smoke at 2500+ rpm - even with the 15x12 2-blade folder. I suppose it could be doing it below that speed but I can't see it.
With all that said, I'm not sure if I'm overpropped or not. I do intend to investigate this further as suggested by you Steve and Druid.
As an added data point, I have not seen any oil consumption of note since we got the boat. We don't motor as much as a lot of cruisers but I do try to run/exercise the engine for 30-40 minutes every time we take it out. This equates to about 20 hrs per year - which ain't much but definitely more than the previous owner who probably put <50 hours in the 10 years he had it.
Maybe I'll start a different thread about loading & engine performance if others post replies on this topic.
 
Jul 28, 2010
914
Boston Whaler Montauk New Orleans
They do defer to the engine data plate for Max Rated RPM and then refer to a maximum loaded rpm for the GM series to be 3550-3650.

With all that said, I'm not sure if I'm overpropped or not.
My understanding of whether a boat is over- or under-propped is that, if at WOT your RPMs are over the maximum RPMs for that engine, you are under propped, i.e you need a prop with more resistance, like increased pitch. If at WOT your RPMs are less than the recomended max, you are over-propped, i.e the prop has too much resistance, like maybe too much pitch.

Keep checking with the engine guys, and if there is a prop specialist near you they can help immensely.

Exercising the engine is a very good thing to do. My boat mechanic's favorite saying is that the worst thing you can do to an engine is not run it.
 
Dec 19, 2006
5,809
Hunter 36 Punta Gorda
Try Mixing Elbo

I had same engine as you and after cleaning out the mixing elbo she ran so much better,I guess after running it so much at low rpm's it the mixing elbo opening got reduced.
Nick
 

Clark

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Jun 30, 2004
886
Hunter 280 Lake Guntersville, AL
Nick, you indicated it ran better. Did you have any smoke produced or was it just that your engine was anemic?
 

Clark

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Jun 30, 2004
886
Hunter 280 Lake Guntersville, AL
Updated Information on CS Performance

Please see additional info in the original post.
 
Jul 28, 2010
914
Boston Whaler Montauk New Orleans
Please see additional info in the original post.
Clark, it seems like you are pretty darn close. Is there a reason you need to be able to reach max hull speed at WOT? Are the reasons big enough to justify a larger engine? Are there other things that might be affecting your max hull speed calculations that you might not have considered?
 

Clark

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Jun 30, 2004
886
Hunter 280 Lake Guntersville, AL
Wink, I just assumed that the engine at some point would drive the boat to (calculated) hull speed. I think that it is "pretty darn close" and have no wish to change prop and certainly not get a bigger engine. As for other factors . . . I dunno.
 
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