"Gould 0738" wrote in message
...

I have lost track of the source, but there is a chart kicking around that
demonstrates the number of gallons of fuel that can typically be burned in
a
diesel cylinder before excessive scoring and ring wear begins. A
6-cylinder
Lehman will burn about 1/3 gallon per cylinder, per hour, at cruising
speed. In
6,000 hours, each cylinder will have burned about 2,000 gallons of fuel.
Compare that to some of the higher HP 6-cylinders that burn several
gallons per
cylinder, per hour- and it helps to substantiate the observation that the
high
revving, light weight, stressed-out "modern" diesels being asked to behave
more
like gasoline engines than traditional marine diesels will also behave
more
like gasoline engines when it comes to life expectancy.

I remain at odds with the statement that one can routinely nurse a
pleasure
boat diesel to the 10,000 or 20,000 hour mark, (the number of years
required to
do so notwithstanding). All the miraculous exceptions, and notoriously
durable
engines like the small Lehman, simply prove the rule. The 10,000 hour
pleasure
service diesel is probably about as rare as the 2700-hour gas engine: I
wouldn't say they don't exist, but neither would I count on typically
getting
that sort of service.

The fuel burned analysis is interesting and, the more I think about it,
makes a lot of sense.
I agree 100% that 10,000 hours or more is optimistic in a marine application
and even Bob Smith was careful to qualify his statement with "failure due to
wear" and advised to watch and maintain the bolt-ons.

Eisboch