On Sun, 10 Jul 2011 08:01:28 -0400, Jay wrote:

On 7/9/2011 11:37 PM, Wayne B wrote:
On Sat, 09 Jul 2011 17:30:26 -0400, wrote:

Bob should install water temp and oil pressure gauges. Also an audible
idiot alarm and maybe an idiot light. He could use the same audible
idiot alarm for both water and oil.

It has been proven that water temp gauges do a great job of telling
you when it is already too late. No joke, usually the damage is done
unless you catch it very quickly.

There are two different sensors that can alert you in time: The first
is a raw water pressure sensor/alarm installed downstream of the raw
water pump. The second is a temperature sensor/alarm at the exhaust
elbow. Either or both of these give you enough warning time to shut
down before damage occurs. Many modern engines have both.


A lot of folks don't glance at their instruments often enough. In bobs
case, a gauge or horn probably would have alerted him to problems. Also
the steam coming out the exhaust usually foretells engine damage.
Misfiring or backfiring could also be a warning sign. Or if the engine
slows down without any other signs you might be experiencing engine
seizure. I'm not trying to scare bob, but he needs to pay attention better.

My point was that no one can watch their gauges every second, and
warning alarms usually go off too late to save damage. Most engines
have some sort of audible alarm for high cylinder head temperature and
low oil pressure. The problem is that by the time temperature hits
the alarm level, you've already cracked the cylinder head or blown the
gasket.

By moving the alarms farther upstream in the cooling system you get
more advanced warning and can shut down without permanent damage being
done. Most of the newer Mercruiser engines with computer controls are
alarmed on both raw water pressure and exhaust elbow temperature. My
7 year old Kohler generator is also setup the same way only with auto
shutdown instead of an alarm. It is relatively easy and inexpensive
to retro fit an older engine with an exhaust elbow alarm and it will
go off almost instantly if cooling water is disrupted for some
reason.