This will probably be of interest to anyone with a Universal 5411 in their boat.
While on a cruise
this past summer to Maine
the Universal 5411 in my Catalina
27 started pumping lots of seawater out of the timing hole in the bell housing. I was able to fix that quickly enough that we were able to continue with the cruise
. I described that experience in some detail elsewhere on this forum - Gord...Need Help 5411/z500
In light of this experience we have decided to convert this engine
to freshwater cooling
to hopefully avoid this problem in the future.
While researching this I spoke with a mechanic
in a large marine engine
shop in Mass. He said that given the freeze plug
failure that I described in the post above, there is likely at least one more ticking time bomb in my engine. It is a steel
plate covering a casting hole on the front of the engine under the gear
cover that is likely to corrode. So last weekend I went in and had a look. It took a couple of hours to remove the gear
cover and at first this steel
plate looked fine. But when I removed it, sea water
on the inside had corroded the underside to the point where it is concave on the inner surface almost out to the edge. It was in fact close to failure. Had it failed we would be injecting sea water
into the timing gears and the engine would likely fail in short order.
I have a machinist buddy that can make me a new cover plate out of bronze or stainless steel and the gaskets and seal that I need to put it back together are Kubota industrial engine parts
I can get quickly here in town, so that part of the job will not be too bad.
Conversion to fresh water cooling
is maybe another matter. I originally thought I would install another neoprene impeller pump much like my existing raw water pump
to pump the antifreeze
. This looked very possible since the rear facing end of the shaft that drives the raw water pump
is accessible and only covered by a steel plate and there is room for a pump. (This is where the hydraulic pump would be located if this engine was installed in a tractor instead of a boat.) When I did the research
, it seems that neoprene impellers are only good to 140 degrees and it would tend to fail frequently if used to pump antifreeze
. Talking to a pump specialist at Depco leads me to think I should use an electric
circulating pump for the antifreeze. This would be a much easier installation
. The difference with an electrical
pump is that I have added another point of failure and the circulation and therefore the cooling is stable at all engine RPM
instead of increasing as engine RPM
Anybody think this is a problem? Or maybe you have other suggestions? Or maybe someone has already done this and I can learn from their experiences. A few 5411s apparently were installed by the boat manufacturer with fresh water cooling at the factory. I wonder how they are set up? Anybody have knowledge or experience to share?