[C320-list] New Boat knocking noise

[Jerry Brown]

Suggestions Please

Our new 320 is sitting at the dealer.  From the day of commissioning there 
has been a loud knocking sound from the stern whenever the boat is motored 
over about 2300 revs - we were told it would "settle down".  In two hours of 
motoring from the dealer premises to our club the engine moved on the mounts 
sufficiently that it jammed the engine cover which was free when we left (I 
checked the oil before leaving).

Initially the dealer "blamed" the Kiwi Prop that I supplied, and he 
installed.  He realigned the engine and told me to take the prop off and 
reinstall the standard two blader.  While still tied to the dock we tried 
the realigned engine (still fitted with the Kiwi Prop) as I was reluctant to 
move the boat for fear of doing more damage.  The dealer also dove under the 
boat to check that the prop was not fouled and that the blades were free. 
In that test the engine was moving around sufficiently to open up the 
stuffing box under load.  The dealer then thought that the initial motoring 
and engine movement might have bent the propshaft.  The dealer then arranged 
to have the boat moved (with minimal motoring) back to his premises.  The 
Kiwi Prop was removed and the shaft and coupling sent to a machine shop for 
checking.  With the boat out of the water it was clear that the shaft was 
not aligned.

The machine shop confirmed that the shaft and coupling are true.  The 
standard prop was then installed, the engine again realigned (the mechanic 
is getting lots of practice) and the boat put back in the water with 
assurances that all would now be good.  The opposite is true.  At 2300 revs 
the noise is more persistent and louder than with the Kiwi Prop.  A 
subsequent test by the mechanics with the engine covers off lead them to say 
that, at the point where the noise starts, the motor can be seen to "move" 
sideways visually.  Another symptom is that when the engine is throttled 
back,  a relatively low frequency vibration passes through the hull which 
can be easily felt at the wheel.  The boat almost seems to be "shaking it's 
hips"  There are no abnormal engine noises etc, no black smoke or any other 
signs of engine problems.  It is smooth at idle and when revved in neutral.

Having confirmed that this is not a Kiwi Prop problem (i.e. my problem from 
the dealers perspective) the dealers' next suggestion is that possibly the 
wrong engine mounting rubber blocks were installed from new.  That seems a 
possibility, but a pretty remote one.  I would welcome other theories as our 
season is rapidly disappearing.

Jerry Brown
#1137 Indigo
----- Original Message ----- 
From: <bruceheyman at cox.net>
To: <C320-List at Catalina320.com>
Sent: Saturday, June 21, 2008 2:40 AM
Subject: Re: [C320-list] PHRF Racing Sails etc


> Rick,
> Our Sailmaker modified the pockets so that we can go with either full or 
> partial battens.  So far our favorite configuration is full for the top 
> two and partial for the bottom two.
> Best,
> Bruce
> Somerset 671 SoCal
> Sent via BlackBerry by AT&T
>
> -----Original Message-----
> From: "Rick Evans" <ericstillwellevans at gmail.com>
>
> Date: Sat, 21 Jun 2008 02:46:26
> To:C320-List at Catalina320.com
> Subject: Re: [C320-list] PHRF Racing Sails etc
>
>
> Thanks Bruce I was really curios on whether the dutchman would work loose 
> footed.
>
> I'm glad it will.
> Sent via BlackBerry from T-Mobile
>
> -----Original Message-----
> From: bruceheyman at cox.net
>
> Date: Sat, 21 Jun 2008 05:14:41
> To:C320-List at Catalina320.com
> Subject: Re: [C320-list] PHRF Racing Sails etc
>
>
> Rick,
> We have a loose footed main and use the dutchman system with no problems. 
> We like the loose footed main as it seems easier to trim the lower third 
> of the sail.
> Bruce
> Somerset 671 SoCal
> Sent via BlackBerry by AT&T
>
> -----Original Message-----
> From: "Rick Evans" <ericstillwellevans at gmail.com>
>
> Date: Fri, 20 Jun 2008 21:17:36
> To:C320-List at catalina320.com
> Subject: [C320-list] PHRF Racing Sails etc
>
>
> I just started PHRF racing my c320 in Western Long Island sound. I was
> wondering if anyone can give me some advise on cruising/racing sails they
> may have upgraded to?
>
> I got some quotes from doyle but I am unsure what to go with.  My main
> questions have to do with the main
>
> 1. Loose footed or not?
> 2. Full battens or not?
>
> I love and want to keep the dutchman and want to know if anyone has used 
> it
> on a loose footed main
>