[C320-list] New Engine Mounts

[Mike Shoffner]

I would think you're correct in your thought that new mounts don't change anything except insulating the hull from the vibration.  I could care less if the engine vibrates as long as it's not transrerred to the hull.  That's interesting that your noise and vibration got worse with new mounts.  The most logical explaination would be stiffer mounts which didn't insulate but rather transferred the vibration to the hull.  I'll ask my mechanic the next time I see him.
Mike



----- Original Message ----
From: Martin Raphael <mraphael at q.com>
To: C320-List at Catalina320.com
Sent: Sunday, June 1, 2008 10:16:54 PM
Subject: Re: [C320-list] New Engine Mounts

Just a thought here...the engine will vibrate the same way in relation to 
RPM whether you have old or new engine mounts, wouldn't it?  Engine mounts 
will affect how that vibration is transmitted to the hull, and thus what we 
hear or feel.  Stiffer mounts will transmit more directly to the 
hull...softer mounts will absorb vibration.  So I wonder if Mike's new 
mounts were actually "softer" than the worn mounts he replaced.  I say this 
because some years ago (2003) I had new engine mounts installed, and the 
engine noise and vibration, especially at low RPMs, went up tremendously.  I 
have always thought this was because the new engine mounts were much stiffer 
than the originals.  Other thoughts?
Martin Raphael
Rhapsody #108
----- Original Message ----- 
From: "Kirk McCullough" <kirk.mccullough at telus.net>
To: <C320-List at Catalina320.com>
Sent: Wednesday, May 28, 2008 9:18 AM
Subject: Re: [C320-list] New Engine Mounts


> Mike
>
> Good advice, I'll add new mounts to the list. I have always put up with 
> the "Perkins shudder" at low RPM, made even a little worse with the high 
> pitched Kiwi prop when in reverse..
>
> Kirk
> #124
> ----- Original Message ----- 
> From: "Mike Shoffner" <drshoffner at yahoo.com>
> To: <c320-list at lists.catalina320.com>
> Sent: Sunday, May 25, 2008 6:08 PM
> Subject: [C320-list] New Engine Mounts
>
>
> Over the years there have been threads devoted to the vibrations at low 
> RPM's of the older boats with Perkins engines. I've noted this with my 
> boat ever since I boughtit 4 years ago, and I've just attributed it to 
> being a characteristic of the Perkins engine. Recently, because of my 
> cutless bearing wearing out in one season of use, I had my shaft 
> allignment checked and was advised I needed new engine mounts. What a 
> difference!! The old "Perkins vibrations" apparently were due to worn 
> engine mounts' and with new mounts there are zero vibrations at low RPM's. 
> At higher RPM's engine noise and vibrations are also noticably reduced as 
> well. Mine is a '94 model and probably needed new mounts for several 
> years. I would advise owhners of more mature boats to consider having 
> their engine mounts replaced if they're having problems similar to mine.
> Regards,
> Mike
> #171
>
>
>
>
>
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