|
|
|
|
|||||
|
||||||
Subject: TWL: Raw Water Flow Alarms
From: bpst (bpst@XXX.XXX)
Date: Mon Oct 01 2001 - 12:05:14 EDT
Good Morning Fellow SlowBaoters.
Saturday I spent with a Detroit Diesel mechanic learning about my 671's.
One of the things we did was change out the raw water impellers on both
engines. In my spare locker I had one Detroit impeller and one aftermarket.
They came with the boat and I have no idea as to their age. I ran both
engines for about 20 minutes at the end of the day, checking everything we
did for leaks and function and all was well. Sunday, my wife planned to
enjoy an unusually warm fall day on the hook beside an island in the
Columbia. When I fired up the engines I immediately got an alarm on the
starboard engine. It isn't uncommon for the alarms to buzz for just a few
seconds after start-up but a little increase in RPM always calms them right
down. This time the tone on the raw water flow was strong and steady and
when I checked the exhaust there was not the amount of water coming out that
I expected. So I shut things down immediately and went below to check
things out. After looking at all the usual external stuff, I decided to
check the impeller. I was amazed, it was totally destroyed. I mean no
blades remaining on the hub. It was the aftermarket product and it appeared
to have disintegrated where the blades attached to the hub. I found another
Detroit impeller, installed it and we were on our way.
Two things. I forget the name of the raw water flow alarm that was
discussed a couple of months ago, but they work. Had I been under way when
the part failed, I could have done considerable damage to my exhaust system
by the time the engine temp gauges/alarms would have alerted me to a
problem. Seconed, Because I do not know the age of some of the spare rubber
parts, particularly the aftermarket ones, I'm getting rid of them.
For what its worth.
Robin Goffrier
Amazing Grace
'81 O/A Mark-1
|