[Alberg30] Fw: Cooling System

[Brian and Elaine Timmins]

Hi all,
I have recently had some over normal operating temperature problems (not
quite overheating) with my A4 and turned to the group for advice. I believe
my problem is over.
  I knew from spring start up that my thermostat housing bypass boss which
was rebuilt once already was getting very thin. Upon running my engine under
load @1500RPM the temp. went up to about 180` which is too hot for a raw
water cooled engine. I reviewed my previous maintenance and considered
several bits of advice from the group and decided to spring for a new
thermostat housing from Moyer/Featherman.
  I installed the new housing this past Sunday and motored around a while. I
also got out on Monday afternoon and motored and sailed for a while. Under
load, my temp. topped out at 160` and at idle and easy run it ran about
150`. Since I'm not quite sure at what temp. precipitation becomes a
problem, I went to Moyer's site and asked him about my current operating
temps. His reply follows:

Dear Brian Timmins,

Thank you for submitting the following question via our web site:

YOUR QUESTION:
My saltwater cooled A4 is running at about 160`. Two- three years ago I did
a strip down and clean out of the entire cooling system and I routinely
flush out with fresh water (2x/year) and use radiator cleaner (1x/year). My
first run this year the temp got up to ~180`. Knowing that my thermostat
housing was worn, I replaced it with a new one from Featherman.(nice
product. congrats on cost control) Now I'm running steady at 160`. Is this
OK or still too hot.

OUR RESPONSE:
Brian,

Yes, 160 degrees is fine.

By the way, is sounds as though you've done a great job in maintaining your
cooling system.

Don

We hope this helps! If you have any additional questions,
please visit our FAQ database again at http://www.moyermarine.com/faq

I guess if Don says it's OK, it must be OK.
Thanks to all who gave some input,
Brian    "Free Spirit"    A30    #497

----- Original Message -----
From: "George Dinwiddie" <gdinwiddie at min.net>
To: <public-list at alberg30.org>
Sent: Wednesday, May 30, 2001 10:23 AM
Subject: Re: [Alberg30] Fw: Cooling System


> Brian,
>
> Overheating problems on raw-water-cooled Atomic 4's are very common,
> and due to any (or several) of a multitude of problems.  I had an
> intermitten problem several years ago that took me forever to track
> down.  It finally turned out to be loose flakes of rust in the exhaust
> manifold that would sometimes block the water flow and sometimes not.
>
> Since there are so many different causes of overheating, I think
> it's best to try to divide the problem space into several areas.
>
> I think that sedimentation in the block will generally cause a
> gradual rise in max temperature, not a sudden change, unless the
> sedimentation has gotten to the point it's blocking the water
> flow.
>
> Is the water flow reduced when the temperature rises?  If not,
> I'd suspect the bypass arrangement.  If the thermostat can't
> shut off the bypass flow, the engine will overheat.  You can
> test this by restricting the bypass hose (the one entering the
> thermostat housing from the waterpump side) with a pair of
> vice grips.  If this cools the engine down, the thermostat
> or thermostat housing is faulty, or possibly the water input
> to the block is plugged.
>
> If the waterflow is reduced, you have to figure out why.
> Either the pump is not pumping efficiently or the flow is
> blocked somewhere along the way.  You can disconnect the hose
> that runs from the block to the manifold to see how much
> water is coming out there.  It's hard to judge, however,
> as the pump can't tolerate much backpressure, and a weakened
> pump (impeller that's lost its spring or too thick a gasket)
> _can_ pump plenty of water against no pressure.  With a cold
> engine, you can disconnect and check the flow at various
> points.  Be careful not to let the water back up the exhaust
> into the cylinders.  Intermittent blockages are always
> difficult.
>
> Let us know what you find.
>
>  - George
>
> --
>  ----------------------------------------------------------------------
>   George Dinwiddie                             gdinwiddie at alberg30.org
>   The gods do not deduct from man's allotted span those hours spent in
>   sailing.                                    http://www.Alberg30.org/
>  ----------------------------------------------------------------------
>
>
>  +-----------------------------------------------------+
>  |     http://www.alberg30.org/store/Galison.html      |
>  | Beautiful notecards of the sea, and other fine art. |
>  +-----------------------------------------------------+
>
> _______________________________________________
> Public-list mailing list -- Public-list at alberg30.org
> http://www.alberg30.org/mailman/listinfo/public-list
> To unsubscribe: email to Public-list-request at alberg30.org
> Include command "unsubscribe <password>" in subject or body.
> Use command "help" for more options.
>
>

 +------------------------------------------------------------------+
 | Simrad TP20 w/ FREE remote, on sale at Sailnet. Search "SIMTP20" |
 |    http://www.myaffiliateprogram.com/u/sailnet/t.asp?id=1066     |
 +------------------------------------------------------------------+

_______________________________________________
Public-list mailing list -- Public-list at alberg30.org
http://www.alberg30.org/mailman/listinfo/public-list
To unsubscribe: email to Public-list-request at alberg30.org
Include command "unsubscribe <password>" in subject or body.
Use command "help" for more options.