Question about engines not started for a while

[Patman]

If you leave an engine unstarted, how long do you think it takes before the bearings and other major parts become bone dry?

I'm arguing with a friend of mine who thinks they go dry in a few weeks, which is why he starts his engine periodically through the winter storage time.

But I told him that an engine would have to sit unstarted for a very long time before it would ever be bone dry, like a year or maybe even more. I told him that there will be a film of oil on the parts even if you let the engine sit for 6 months.

What do you guys say?

 

[michaelc80]

I've torn down a Ford N tractor engine that was last run about 6 months or so before I got it and it still had a film of oil on it (I wouldn't have been worried about starting it if it didn't need rebuilt). I rebuilt an AC "G" once that had been sitting for "several years". It was extremely dry.

 

[Mike_dup1]

I doubt it would ever go dry in a year or more. Oil will cling for a long time. Tell him to take some metal and coat it with oil. Put in in a sealed can and see what happens.

 

[Kestas]

One specific scenario that can happen is that the valve springs go dry, then a corrosion pit may develop. Once the vehicle is put back into service, the corrosion pit than becomes an initiation site for a fatigue crack, resulting in a broken valve spring.

How long it takes for an engine to go dry is anybody's guess. Michael did a good job of bracketing it for you.