Help Me to Understand Dry Start ?

[DonBaja]

Let's assume the Cummins 8.3L diesel hasn't been started for a month.

When I turn it over - is it dry metal on dry metal on the main bearings and crank? Or is it possible that the main bearings are sitting in an oil bath of some sort. There are a couple of seconds between the engine firing and the oil pressure coming up. I assume that the bearings feel oil pressure before the pressure sensor does and then the signal has to travel 36 feet to the gauge. I have felt how smooth crankshafts are where they come in contact with the main bearings and I know these main bearings are relatively soft. Having said that - does your engine die a little every time it sits for a month between starts? Are there other contact points like rod bearings that suffer as much or more than the main bearings? Thanks in advance for your insights!

[wa8yxm]

This does not address the O/P's question but I have a thought......

Why can they not put an "oil Priming Pump" on the engine, a small electric you run for like 30-60 sedonds to "Prime" the oil system and get oil up to the top rail?

I guess the engine makers do not feel it is needed.

[ScottG]

You really don't need to worry about the "dry start" scenario. It just isn't an issue.

[wolfe10]

Let me rephrase. Per Cummins (as well as Caterpillar, etc) if you start it, drive it at least 25 highway miles-- enough to get the OIL, not just coolant up to operating temperature. It is moisture in the crankcase that you want to avoid, and you can not get the oil up to operating temperature except by driving at highway speeds/under load.

[Ivylog]

Yes it dies every time you start it so another reason to not start it every month. Good news... it has thousand of lives as there's a little oil still in there.

[Old-Biscuit]

Let's assume you haven't started it since yesterday.

Engines die a little every time you start them....no pre-oilers but oil is pretty darn good at coating parts and leaving a bit of residue.

If you do decide to start it........take it for a spin. That's better for it then just starting it.

[davebrown]

DonBaja wrote:
Let's assume the Cummins 8.3L diesel hasn't been started for a month.

When I turn it over - is it dry metal on dry metal on the main bearings and crank? Or is it possible that the main bearings are sitting in an oil bath of some sort. There are a couple of seconds between the engine firing and the oil pressure coming up. I assume that the bearings feel oil pressure before the pressure sensor does and then the signal has to travel 36 feet to the gauge. I have felt how smooth crankshafts are where they come in contact with the main bearings and I know these main bearings are relatively soft. Having said that - does your engine die a little every time it sits for a month between starts? Are there other contact points like rod bearings that suffer as much or more than the main bearings? Thanks in advance for your insights!

short simple answer.NO and u don't need to start the motor every month
If you do u must get it up to full operating temperature for XX minutes