[C320-list] A High Pitched Whine Noise

[Karl Mielenhausen _/)]

I had anti-fouling applied to the prop (fixed, 3-blade) and shaft at the  
last haulout. Immediately observed the same sort of high pitched whine  
between 1100-1900 rpm. Good news is no barnacles after one year.

Karl Mielenhausen


On Fri, 10 Sep 2010 12:57:29 -0400, Utility Email  
<kswanson123 at comcast.net> wrote:

> We after trucking out C320 all the way from San Diego to Seattle,  
> spending a week in the Seattle boatyard repainting the bottom, waxing  
> the hull, and inspection restepping the rig, our beautiful boat is back  
> in the cool waters of Puget Sound.
>
> However, we also have a new sound...
>
> When motoring between, say 1800 and 2200 RPM, there is a high pitched  
> whining sound coming from the shaft area.  The noise is more like a high  
> pitched whistling or whining sound. The sound is very high pitched and  
> sharp in tone.
>
> After doing a list-server search, I read somewhere that it could  
> possibly be a high pitched harmonic with our stock 3-bladed propellor  
> and a "fix" could be to "dull" the leading edges of the blades. I'm not  
> sure that I buy this explanation/fix without other input, but I am at a  
> loss for another rational explanation.  Hence, this is why I am  
> inquiring through our C320 list server.
>
> We never heard this sound before in our C320 after operating the boat  
> for the last year, or any other boat we have had.  Has anyone else  
> experienced this type of noise coming from the drive train area?
>
> A couple of other facts about some basic changes to the boat from San  
> Diego to Seattle:
>
> 1. We cleaned the prop and applied 3 coats of Petit (barnacle buster)  
> zinc paint to the brightly cleaned bronze 3-bladed prop during our  
> recommissioning in Seattle. The prop was cleaned with vinegar and a wire  
> brush to a bright metal finish, no filing or edges of the prop were  
> sharpened in the cleaning process.
>
> 2.  I cleaned out the stock flax shaft packing and installed 2 rings of  
> new 1/4" Gore Tex GFO packing. I adjusted the drip rate to about 3 drips  
> per minute under power, and we still get high pitched sound.
>
> 3.  I have not checked the engine and shaft alignment yet. I am thinking  
> of hiring a mechanic to check and realign the shaft to the engine since  
> the boat was transported from SAN to SEA by truck.  Do others agree that  
> the engine and shaft should be aligned after overland trucking of the  
> boat?
>
> 4.  New zincs are installed on the propellor shaft and strut. I doubt  
> this has any affect.
>
> 5.  Yesterday we motored for about 5 hours to transit the boat from the  
> Seattle-based boatyard to our home marina. The high pitched sound was  
> present when we started and also when we arrived at our marina.
>
> 6.  The engine has about 100 hours on it and it has been well taken care  
> or and services regularly.
>
> If the sound doesn't indicate that there is nothing mechanically wrong  
> with the boat or drivetrain, then it is just an annoying sound that I  
> will avoid while operating the engine.  If not, then I would like to  
> learn about what I should do to fix it.
>
> Any and all comments, advice, and/or a fix would be appreciated.  Please  
> weigh in with your experience.
>
> Thanks!
>
> Dave Swanson
> S/V Emily Ann
> 2007 C320 MK II, No. 1107
> Mukilteo, WA
>


-- 
Karl Mielenhausen
Catalina 320 Hull 690