[C320-list] Normal Performance Limits?

Sat Oct 4 10:22:27 PDT 2008

Bert:

I understand the analogy. But it seems to me that my knotmeter must be 
registering unrealistically low speeds when it always, and I mean always, 
shows one or two knots less than SOG.  And this also happens when running 
under power only. It seems doubtful to me that the difference is always 
current. Anyway, I consider this to be more a situation than a problem to be 
solved.

The leaking fresh water connector under the head sink, on the other hand, is 
a problem.  I'm not getting any takers on that one. Apparently no one else 
has had the same experience.

jack
sure bet #947

----- Original Message ----- 
From: <BAdams3491 at aol.com>
To: <C320-List at Catalina320.com>
Sent: Saturday, October 04, 2008 9:07 AM
Subject: Re: [C320-list] Normal Performance Limits?

> Jack,
>
> Using speed over ground is fine for determining when you'll get some 
> where.
> However, it tells you nothing about  how your engine is  running as far as
> speed is concerned.  If an airplane is flying at 200  knots, but  has a 50 
> knot
> headwind, it's only going 150 knots over the  ground...same with a boat 
> only
> the variables are wind, current, tide, etc.
>
> Bert
> At Ease
> #442
>
>
> In a message dated 10/4/2008 10:21:37 A.M. Central Daylight Time,
> mcdonough5 at verizon.net writes:
>
> Monte  & Bert:
>
> My 320 is now on jackstands for the winter after another  short New 
> England
> season. Now I'm eager to get in the water in the spring  to see how the
> engine sounds at 3000 to 3600. It has always seemed to me  that it 
> "sounds"
> like it is content at the lower  rpms.
>
> Additionally, I have always thought that the knotmeter reading  was lower
> than the actual speed of the boat through the water. It  regularly records
> speeds  in the 3, 4 and 5 knot range when I'm  certain I'm going faster 
> than
> that by any visual estimate. That's why I  pay more attention now to the 
> SOG
> when I'm intent on getting where I'm  going.
>
> And, while I have your attention, has anyone read my earlier  e-mail about
> the leaking fresh water connector under the head  sink?
>
> Jack
> #947
>
>
>
> ----- Original Message -----
> From: "Monte B." <mjbc60 at sbcglobal.net>
> To:  <C320-List at Catalina320.com>
> Sent: Saturday, October 04, 2008 6:32  AM
> Subject: Re: [C320-list] Normal Performance Limits?
>
>
>>I  have owned mine since new in 1999 and have accumulated about 750 
>>engine
>> hours. For most of those hours I ran it very conservatively at  2500 
>> RPM's
>> and not quite 6 knots. After reading the posts about  exhaust elbow 
>> coking,
>> I
>> pulled my ex. mixing elbow and found  it to be quite coked but nowhere 
>> near
>> plugged as some have reported. I  now run it at 3000 and it is actually
>> smoother at that RPM and  obviously faster at the expense of a higher 
>> fuel
>> burn. I think Yanmar  calls for max RPM of 3600 and max continuous of 
>> 3400.
>> I
>> have  come to believe that diesel's like to work near their design load
>>  limit
>> and at lower RPM and load tend to run rich and the lower exhaust  gas
>> temperatures cause exhaust component coking. I don't know how they  avoid
>> this with automobile diesel engines but they are not designed to  be
>> continuous duty cycle as these small industrial and marine engines  are.
>>
>> Monte
>> Laima #620
>>
>> -----Original  Message-----
>> From: c320-list-bounces at lists.catalina320.com
>>  [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Jack
>>  McDonough
>> Sent: Saturday, October 04, 2008 7:37 AM
>> To:  C320-List at Catalina320.com
>> Subject: Re: [C320-list] Normal Performance  Limits?
>>
>> I've had my 320 since it was new in 2003 and I have  never run my Yanmar 
>> 27
>> much more than 2600 or, rarely, 2800 rpm. With  a three-blade prop, I'm
>> probably doing about 6 knots over the ground.  My recollection is that
>> those
>> rpms are about what the engine  mounting plate and the Catalina manual
>> suggest. Am I right or  wrong?
>>
>> Jack
>>  #947
>>
>>
>>
>>
>> ----- Original Message -----
>> From: "Monte B." <mjbc60 at sbcglobal.net>
>> To:  <C320-List at Catalina320.com>
>> Sent: Friday, October 03, 2008 8:46  PM
>> Subject: Re: [C320-list] Normal Performance  Limits?
>>
>>
>>>I didn't disagree with Rod. I reiterate,  these instrument systems 
>>>(tachs)
>>> are poorly calibrated and if you  normally run your engine at a
>>> conservative
>>> RPM and  then firewall it you may expect to see smoke just from the 
>>> higher
>>>  exhaust gas temp burning combustion deposits out of the exhaust 
>>> system.
>>> That
>>> having been said I would agree that prop  pitch controls max. RPM.
>>>
>>> Monte
>>> Laima  #620
>>>
>>> -----Original Message-----
>>> From:  c320-list-bounces at lists.catalina320.com
>>>  [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of
>>>  joe at dolphinmortgage.com
>>> Sent: Friday, October 03, 2008 8:32  PM
>>> To: C320-List at Catalina320.com
>>> Subject: Re:  [C320-list] Normal Performance Limits?
>>>
>>> I agree with  Rod, low RPM and black smoke with clean bottom & Prop 
>>> means
>>>  it
>>> is overpitched. Should run at 3600 RPM at Max  throttle.
>>> Joe Barrett
>>>
>>> -----Original  Message-----
>>> From: Monte B.  [mailto:mjbc60 at sbcglobal.net]
>>> Sent: Friday, October 3, 2008 08:53  PM
>>> To: C320-List at Catalina320.com
>>> Subject: Re:  [C320-list] Normal Performance Limits?
>>>
>>> These boats  also have notoriously inaccurate tach,s, something else to
>>> check.  Monte Laima #620 -----Original Message----- From:
>>>  c320-list-bounces at lists.catalina320.com
>>>  [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Rod  Boer
>>> Sent:
>>> Friday, October 03, 2008 7:12 PM To:  C320-List at Catalina320.com Subject:
>>> Re:
>>> [C320-list]  Normal Performance Limits? It sounds to me that you are 
>>> over
>>>  propped. You should be able to get up to 3400 RPM. Can you adjust  the
>>> pitch
>>> on the Kiwi? If so, just reduce the pitch  and you should be able to get
>>> up
>>> to the full RPM Rod  Boer Odyssey, #688 -----Original Message----- From:
>>>  c320-list-bounces at lists.catalina320.com
>>>  [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of  Amirault
>>> Family - S&B Sent: Friday, October 03, 2008 7:01 PM  To:
>>> c320-list at catalina320.com Subject: [C320-list] Normal  Performance 
>>> Limits?
>>> I
>>> had my boat on the water  yesterday afternoon for likely the last sail 
>>> of
>>> the
>>>  season. Although the wind was 15-20 knots on departure it had dropped 
>>> to
>>> near nil by the time the crew decided to head for home. To  ensure we
>>> arrived
>>> at the dock before dark I slowly  pushed the throttle to maximum. On 
>>> still
>>> water this gave me revs  at 2900, knots at 6.75 and plenty of black 
>>> smoke.
>>> On
>>>  easing the throttle back to 2500 revs I was able to maintain 6 knots 
>>> and
>>> eliminate the smoke. I have a Yanmar 3GM30, a clean bottom and  a Kiwi
>>> prop.
>>> Is this approximately normal? Brian  Amirault #797 Waltzing Bear, too
>>>
>>
>
>
>
>
>
>
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