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(Steven Shelikoff) wrote in message ...
On Wed, 16 Jul 2003 18:12:25 GMT, Brian Whatcott
wrote:

On 16 Jul 2003 08:48:08 -0700, (brad) wrote:

Brian Whatcott wrote in message . ..
1900 running hours suggestds that overhaul time is due soon, maybe
very soon....

Brian Whatcott Altus OK

1900 hours time for a overhaul? I am not a mechanic, but I thought one
of the reasons one would go with a diesel is for its reliability. If I
had a piece of equipment that operated 8 hrs a day, 1900 hours would
be about 237 days of
operation . Most of the machinery ( diesel powered ) at my work
operates 24 hrs a day. The equipment does get a service ( oil and
filter change) every 250 hrs of operation. What a huge liability if
they had to overhaul every 1900 hours.

It's pleasing to hear about long-life engines.
Used to be, recips used on light aircraft had a mandated overhaul time
- for most of them it was 2000 hours. Now its "on condition" like
jets....

Comparing auto engine lives:

You would like to make 150 thousand miles plus before tearing an auto
down (certainly we are making those numbers on a pair of econoboxes
we own.) If you averaged 40 mph long term - that would be 3750
hours.

Yes, but if the auto engine spent a very high percentage of it's life
at, say, 80% max hp, you wouldn't be getting anywhere near those hours.
Cruising along at 55 mph, the average auto engine is probably only
operating at around 10% load.

True, but proper diesel engines are designed to operate under load.
The usual and only worthwhile rating is the continuous one, and it (at
least used to) mean what it says. Fed clean air, fuel and with routine
servicing, diesel engines will run for many, many thousands of hours.
Boat engines have a pathetic life mainly due to their operators'
ignorance. The other problem is engines that are started, run for 5
minutes and then shut down again.

Personally, provided spares were still available, I'd rather have an
older engine running at 1800 rpm than a newer one running at 3600 rpm.
You need a 2:1 reduction in the first case to get your prop shaft
speed below 1000 rpm and can swing a big 2 blade prop slowly. Finding
4:1 reduction boxes - I haven't seen any commonly offered.

My nearly 40 y/o Perkins diesel in my tractor *always* starts and I
bought it in 1988. Over the last 15 years, all I've ever done is
change the oil and filters.

Peter Wiley