[C38] heat exchanger

[Charles Finn]

Welcome Jon!
As you can see, replacing the heat exchanger has been a "hot" topic for 
the Catalina 38 crowd!  The original 2" exchanger was marginal at best, 
with any obstruction leading to overheating.  Mine has zebra mussel 
shells obstructing the core.  Apparently, they grow within the 
exchanger, which means I will have to add this inspection to my ongoing 
maintenance list.  You have already removed your exchanger and I am 
guessing you did so through the port sail locker, which is not fun to 
say the least even if you have made the cut-out modification....  
Installing it can be even less fun.  BUT! it turns out there is an 
easier way that works for even our larger crew (myself for example).

There are four hoses connected to the heat exchanger.  Two carry engine 
coolant, with one coming directly from the manifold and the other going 
to your water heater.  The other two carry seawater.  Three of these 
hose clamps can be accessed from the starboard side of the engine by 
taking out the pilot berth cushion and access panel covering the fuel 
tank.  There is enough room to get your arm in and to see what you are 
doing.  If you want even more access,  install an inspection port 
($25-50), which is what I am doing.  The fourth hose can be disconnected 
on the forward, lower, port side of the engine, which can be easily 
snaked in or out with the removal of the heat exchanger.
You will doubtlessly notice the larger exchanger will not fit in the old 
mount on the motor.  I hung mine from the engine ceiling using two pipe 
hangers available at any home depot for $2-4.  I can now remove, inspect 
and remount the exchanger in about 1/2 hour.  Can't do it by myself at 
the fourth hose has to be caught by someone as it is snaked back up to 
the front of the engine (my wife did this last time and despite 
protesting loudly that she never signed up to work on the engine.. she 
didn't even get a grease smudge)!

Note:  I always double clamp hoses with good 314 stainless marine clamps 
that have a hex head which allows for the use of a socket.   This allows 
me to tighten clamps at almost any location without having to see what I 
am doing as the socket fits neatly on the clamp.  As all my hose clamps 
use the same socket size, I have a universal hose clamp tool readily at 
hand in the toolbox.

Chuck Finn
Mighty Quinn  #114
Great Lakes


Steve Smolinske wrote:
> Jon, 
>  
> Congrats and welcome you'll find this list is an invaluable resource.   I also replaced mine the cost was $330 as Bob mentioned the link to the company in Victoria is http://www.manifoldwarehouse.com/mes/mgr?brch=home  that was for the largest of three sizes that will work with our engines.  The extra money is well spent as we also run 20-30 degrees cooler and the engine sounds so much better.  There was quite a thread going last year on heat exchangers you may want to surf the archive if you haven't already.  My project grew to include replacing all the hoses, the fresh and raw water pumps too along with the thermostat for good measure.  Tom T. pointed out last year that our water pumps have internally lubricated bearings and those pumps if original are 25 years old.  That's why my job grew it didn't make sense for me to pull everything else apart and not replace something that was just lurking, just waiting for the most inopportune time to break.
>  
> Steve
> Peregrine #312
> Seattle
>
> ________________________________
>
> From: listserve-bounces at catalina38.org on behalf of Jonathan Whitney
> Sent: Fri 3/5/2010 12:39 PM
> To: listserve at catalina38.org
> Subject: [C38] heat exchanger
>
>
> Hi,
> I am a proud new owner of a '79 Cat 38 "Kuu Haku".  The engine is a Universal 5424.  Recently had some overheating issues when sailing back from Maui to Oahu.  Coolant was leaking somewhere, temp gauge reading over 200 F.  Replaced scaled seawater lines, removed the heat exchanger (3" replacement, I'm guessing, as I think the 5424 originally came with a 2" exchanger).  It was visibly clogged and anode totally gone.  So I took it to a radiator shop to get boiled.  They called and said there were a bunch of leaks and needs to be replaced.  My question is:  Is it possible to replace just the core, or should I just get a replacement exchanger?  Also, has anyone replaced a similar unit for less than the ~$400 at Torrensen.  Are there any replacement brands to stay away from, or others people have had good luck with?  
>  
> Also, as I have noticed a slow leak in the coolant, it seems safe to say that FW/antifreeze is leaking into raw water, but should I assume seawater has contaminated the FW side.  I have drained and flushed all the FW coolant, but if there is a chance seawater has gotten in the lines should I do something else to treat the FW side to ensure all seawater is flushed out.  
>  
> Any information would be really appreciated.  
>  
> Jon Whitney
> 1979 Cat 38 "Kuu Haku"
> #54
> Honolulu, Hawaii
> = 
>   
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