[C320-list] New Boat knocking noise

[Jerry Brown]

Interesting.

Thanks.
----- Original Message ----- 
From: <bruceheyman at cox.net>
To: <C320-List at Catalina320.com>
Sent: Sunday, June 22, 2008 11:00 AM
Subject: Re: [C320-list] New Boat knocking noise


> Jerry,
> A mechanic in St. Petersburg FL told me that the mounts for the Yanmar are 
> too soft.  He said you can get everything lined up but when the engine was 
> up to speed the torque would cause the engine to twist and hence the log 
> and cuttlas were no longer in alignment.  He said that for that reason 
> Yanmar now has two versions of the mounts for our boat, one soft (quite 
> and smooth) and the other stiff (stays in alignment).  I never verified 
> the mechanic's information.
> Good luck.
> Bruce
> Somerset 671 SoCal
> Sent via BlackBerry by AT&T
>
> -----Original Message-----
> From: "Jerry Brown" <jbrown03 at sympatico.ca>
>
> Date: Sun, 22 Jun 2008 07:31:12
> To:<C320-List at Catalina320.com>
> Subject: Re: [C320-list] New Boat knocking noise
>
>
> Hi Rick
>
> I spent time yesterday with the dealer on the boat motoring around while 
> he
> crawled all over it.  I think you have correctly diagnosed the problem as
> the shaft hitting the hull.  In my case it appears that the engine is
> sitting too high in the boat relative to the tunnel for the shaft to clear
> the tunnel in all conditions  When the engine is aligned and running 
> slowly,
> the shaft just clears the tunnel.  At higher speeds and under load, the
> movement in the mounts (which are secure) is sufficient to allow the shaft
> to hit the tunnel, just as you describe.  The dealer could push briefly on
> the engine while it was running under load and immediately there was no
> knocking.  Release the engine and back came the knocking.  The next move 
> is
> to install slightly thinner plates under the engine, lowering the who 
> thing
> while maintaining the right overall relationships (which will change the
> angle of the shaft through the cutlass bearing somewhat) and try again.
> While this likely explains the knocking noise, it does not explain the
> engine shifting when first used.  Yesterday I noticed metal swarf around 
> the
> engine mounts.  It turns out that the holes in the metal plates under the
> engine needed to be enlarged to allow enough lateral movement for good
> alignment, this was done last week.  When the boat was delivered, the
> mechanic had pushed the engine hard to the side of it's allowable movement
> (not enlarging the holes) which meant that he likely could not get a full
> tighten down even when he thought he had.  The engine simply moved across
> when loaded.  The boat came from the factory that way, with the engine
> sitting high and with insufficient adjustability for alignment, suggesting
> some excessive design tolerances or quality control issues there.  The
> dealer did not pick this up on commissioning - and without detailed
> measurements and drawings it would have been hard for him to do so - hence
> all the grief.  I do fault the dealer mechanic for not realising that the
> engine was at the limit of it's movement when he first aligned the engine,
> or for doing nothing about it if he did realise.
>
> Once the engine has been lowered it will be tested with the standard prop.
> If the knocking problem has been solved, the Kiwi Prop will be reinstalled
> and tested again.  We can then hunt for the water leak which causes the
> water pump to cycle every 30 seconds or so and numerous other details.
>
> I am more hopeful now, but the proof will will be in the next round of
> testing.  Thanks to every one for their suggestions and support.  The 
> dealer
> told me that he plans to call Gerry Douglas Mon to discuss the whole saga
> with him ( and presumably to discuss the ensuing warranty claim which will
> be significant).  For those who suggested withholding funds.  I did indeed
> keep a significant hold back, though the bare hull was paid for soon after
> delivery as I wanted title to the hull.  That holdback has not been paid
> (nor asked for).
>
> Regards
>
> Jerry Brown
> #1137 Indigo
> ----- Original Message ----- 
> From: "Rick Sulewski" <rsulewski at earthlink.net>
> To: <C320-List at Catalina320.com>
> Sent: Saturday, June 21, 2008 5:52 PM
> Subject: Re: [C320-list] New Boat knocking noise
>
>
>> Jerry,
>>
>> Sounds like the shaft may be flexing and banging against the hull.
>>
>> I had a similar sound back when I had a brass shaft and my engine was
>> flip-flopping around before I discovered that the mounting studs had
>> worked
>> loose. Whenever I accelerated quickly or whenever I would turn hard over
>> under extreme throttle positions and with high hull speeds I would hear a
>> repetitive banging noise.  I figured it was from the shaft flex
>> exacerbated
>> by the shaft torque deflection permitted by the loose motor mounts. The
>> sound would cease when I returned the wheel to center or lowered the
>> engine
>> speed.
>>
>> That banging noise condition subsided, but did not entirely disappear 
>> when
>> I
>> fixed the loose motor mounts. I had to replace the brass shaft a few 
>> years
>> later with stainless shaft due to a line getting entangled in the prop,
>> and
>> now I rarely hear the banging noise unless I am backing up under 
>> extremely
>> hard acceleration when I need to quickly control the bow swing if I have 
>> a
>> strong cross wind in the fairway.
>>
>> Wonder if your engine mounts are secure since the shaft and coupling are
>> true. Since you have aligned the shaft, the only other consideration 
>> would
>> be your strut flexing if it is loosely mounted or if it is misaligned
>> relative to the shaft exit.
>> .
>> Rick
>> My-Ria 277
>>
>>
>>
>> -----Original Message-----
>> From: c320-list-bounces at lists.catalina320.com
>> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Jerry Brown
>> Sent: Saturday, June 21, 2008 7:29 AM
>> To: C320-List at Catalina320.com
>> Subject: [C320-list] New Boat knocking noise
>>
>> 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
>>>
>>
>>
>
>