Starting Diesels for short periods of time

[Midniteoyl]

The RV guys say not to do it.. Idling for long periods is also frowned upon as it can lead to scored cylinders. Somewhere is a CAT pdf on the subject..

 

[daugen]

always wondered why they didn't incorporate a pre-lube cycle during the initial glow plug warm up period.
Of course the best thing would be a nice heated oil pan sending warm lube to all the right spots...

 

[daugen]

that got me to thinking about that 90% wear figure. Not sure exactly what the details are there.
What if the total wear was insignificant, but 90% really did happen on startup?
Now if they said 90% of the wear directly responsible for a rebuild or major repair was caused in starting, well, that would
sure be a lot more credible to me.

I just bought a new portable gen and when that thing fires up and goes directly to 3600rpm, boy does that make me cringe. At least on the tractors I can start at idle or just above.
Sometimes on cold days I'll turn a gasoline motor over a few times without putting on the choke, trying to move the oil a little. Not sure I'm accomplishing much. If that fresh oil hasn't dripped down onto those rings within a millisecond of that engine moving, on a microscopic scale, I don't think it will look pretty. Doesn't seem to be the rings that get wrecked, isn't it usually the dry rings scoring the cylinders?

 

[JasG]

always wondered why they didn't incorporate a pre-lube cycle during the initial glow plug warm up period.
Of course the best thing would be a nice heated oil pan sending warm lube to all the right spots...

Caterpillar (I think I remember correctly, or possibly a company did test cat machinery) did some testing in the early 1990's I believe. I remember reading about they used an electric oil pump and it greatly reduced engine wear. This because the engine wouldn't turn until it had oil pressure. The engines still had a mechanical pump as I recall.

I never saw it go into any production engine, probably because it greatly reduced engine wear. These companies do make a lot of money from parts.

It's not uncommon as has already been said for engines that are kept running to have 3-4 times and more, the hours with out issue.

 

[JasG]

I did find a company that makes a filter, pump system that pumps oil before start up, filters the oil extra and post shutdown.

http://www.maxilubesystems.com/Maxilube_Systems_LLC.pdf

 

[daugen]

I did find a company that makes a filter, pump system that pumps oil before start up, filters the oil extra and post shutdown.

http://www.maxilubesystems.com/Maxilube_Systems_LLC.pdf

that would sure get the job done, except for warming. These prelubers, I think, are very common in larger engines, say over 20 liters. They are very common on large yachts with seriously expensive diesels in them. The proverbial ounce of prevention. Actually I've seen large yachts with Alfa Laval separators and all kinds of oil cleaning systems, usually on long range trawlers or large passagemakers. It's all trickle down tech from the big ships, the really big ships, that have all this stuff standard, and probably redundantly.

 

[RaydaKub]

But they are up to operating temp.

Not only are they up to operating temp, they are fully lubricated and only drain the oil down for a few minutes. There is going to be a lot less wear starting an engine that had oil running through it 5 minutes ago than one that hasn't had oil pumped through it for a month or 3 or 10.

 

[AGRIMAN]

I sure wouldn't loss any sleep over 90% engine wear at start up.

 

[Midniteoyl]

always wondered why they didn't incorporate a pre-lube cycle during the initial glow plug warm up period.
Of course the best thing would be a nice heated oil pan sending warm lube to all the right spots...

They have oil accumulators that will will prelube

 

[bdog]

Interesting question. I have a skid steer that where I park it in my shop I have to move it on a regular basis to get access to other things. Maybe 2-3 times a week it gets started and backed out and then later started and put back in. I always assumed this was not the best for it but I think it is better than leaving it sit outside all the time.