[C38] engine temp

[Tom T.]

Hello Bill,

The older Universal engines were famous for overheating with the original
2" diameter heat exchangers.

I have a weld shop and fabricated a larger heat exchanger from 3" hard
copper instead of the original 2" diameter.  I used basically the same
length as the original exchanger but was able to get about twice the number
of cooling tubes installed in the larger diameter pipe doubling my cooling
capacity.

My boat sails the Tampa Bay area which is some of the warmest cruising
water in the USA  Since I installed the new heat exchanger, my engine stays
at about 200 degrees which is the thermostat temperature.   I've  motored
against the tide on hot windless days and at full throttle my engine will
not overheat now.

I had chartered an old O'Day some years back and it had the Universal 5424
as my Catalina 38 does.  The charter company told us not to exceed 2,200
RPM or the engine would overheat.  That was back in the mid '80s but was my
first introduction to the Universal engines overheating problem.

As one final thought, any heat exchanger should be connected with reverse
flow of the liquid hoses.  In other words, the coolant water should go in
an opposite direction as the raw water.  If the liquids travel in the same
direction the efficiency of the exchanger is greatly reduced.  As old as
our boats are, there is a chance that the hoses could have been reconnected
in the wrong fashion making the small, inadequate heat exchanger an even
worse problem.

Tom Troncalli
The Renata, Hull 95, St. Pete Florida




> [Original Message]
> From: William Knowles <william_k_19810 at yahoo.com>
> To: <listserve at catalina38.org>
> Date: 7/10/2007 2:54:36 PM
> Subject: [C38] engine temp
>
> What is the normal operating temp for our unervisal
> engine? Last weekend I was running @ 1800 to 2100 rpm
> and engine slowly crept up to 210 to 225 f. Is this
> normal? We are pumping water and the impeller looks
> new. Would like to know your thoughts before calling
> in the  engine guys. I did not check the incoming
> filter as I could not get the plastic cover off and
> did want to break it away from home. Can I bypass the
> filter if I have to. Thanks in advance fior your help.
>
> Bill Knowles Flying Goose
>
>
>  
>
____________________________________________________________________________
________
> TV dinner still cooling? 
> Check out "Tonight's Picks" on Yahoo! TV.
> http://tv.yahoo.com/
>
> _______________________________________________
> Listserve mailing list
> Listserve at catalina38.org
> http://catalina38.org/mailman/listinfo/listserve_catalina38.org
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition. 
> Version: 7.5.476 / Virus Database: 269.10.2/893 - Release Date: 7/9/2007
5:22 PM