[C320-list] Heat exchanger core and mixing elbow

[Warren Updike]

Boy, I second this.  Things that tend to carbon-up an engine are: running in
neutral to charge batteries (run in reverse at anchor or mooring if
possible;) extensive motoring at low rpms.  Whenever possible I try to motor
at 25-2700rpm (Perkins M30, different for different engines.)  We have over
2,100 hrs, our smoke is nearly invisible, always starts quickly, and burns
not more than 1/2 qt. oil between changes.  

Also, check mfgr recommendations first; but, I understand that ULSD needs a
cetane booster with lubricity additives.  I'm quite sure Yanmar recommends
this.  If you fuel dock advertises Valve-Tec diesel, apparently you don't
need such an additive.  We've seen a few of these fuel docks on the lower
Chesapeake.

Warren & Pattie Updike
1994 C320 #62 "Warr De Mar"

-----Original Message-----
From: Irving Grunes [mailto:igrunes at gmail.com] 
Sent: Monday, October 07, 2013 5:49 AM
To: C320-List at catalina320.com
Subject: Re: [C320-list] Heat exchanger core and mixing elbow

I think that its extremely important to run the engine hard under laod for
several hours from time to time to burn out the carbon in the mixing elbow.
Those boats with very low hours are probably the most susceptible to mixing
elbow failure.
Irv Grunes
2001 #851
Isle of Wight


On Sun, Oct 6, 2013 at 9:00 PM, <dprudden at comcast.net> wrote:

> I have a friend who has the same engine as me (and a lot of you), a 
> 3gm30f. He works for a very reputable (and expensive) boat yard in 
> Massachusetts. He says, and his yard agrees, that the mixing elbow 
> should be replaced every 5 years and the heat exchanger core should be 
> pulled and sent out to be properly descaled/cleaned every 5 years as 
> preventative maintenance. I know there was a recent discussion about 
> cleaning out the mixing elbow, and this is obviously more than that. Agree
or disagree?????
> I sail in salt water. Does the number of hours used each year matter?
>
> Thanks for the help and advice!
>
> David Prudden
> #787
>