What's wrong with idling?

[Dreadnought]

Shouldn't any accumulated oil in the airboxes simply drain out of the slo..er tubes, at least until their check valves close at about High Idle's airbox pressure?

John

Yes- and someone's put these catch cans on mine. Regardless- I've had my engine blip and run away a bit after prolonged idle- sounding really clattery while the oil burned off.

The other point I SHOULD have mentioned is that obviously Detroit knew about this and that in the myriad applications of this engine idle may be required (like in the example above)- which is why they fitted the fast idle circuit where it probably scavenges a lot better.

[Scott & Heather]

So after idling all night, we drove away....I had quite the puddle of oil underneath...and boy oh boy I wish I had taken a video of the exhaust when I took off down the road....let's just say I'm pretty sure no one saw the sun shine that day anywhere in the state....even though it was a clear day...


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[Iceni John]

Yes- and someone's put these catch cans on mine. Regardless- I've had my engine blip and run away a bit after prolonged idle- sounding really clattery while the oil burned off.

The other point I SHOULD have mentioned is that obviously Detroit knew about this and that in the myriad applications of this engine idle may be required (like in the example above)- which is why they fitted the fast idle circuit where it probably scavenges a lot better.

The 9-89 edition of Detroit's Operator's Guide for Series 53, 71 and 92 states on page 7:

Avoid Unnecessary Idling
During long engine operating periods, the engine coolant temperature will fall below the normal operating range.   The incomplete combustion of fuel in a cold engine will cause crankcase dilution, formation of lacquer or gummy deposits on the valves, pistons and rings, and rapid accumulation of sludge in the engine.   When prolonged engine idling is necessary, maintain at least 800 RPM.

John

[Scott & Heather]

So in other words close your shutters and idle away


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[buswarrior]

Just like every 2 stroke in the truck stop back in the day.

We just didn't notice, since the trucks rolled coal while they moved too...

happy coaching!
buswarrior

So after idling all night, we drove away....I had quite the puddle of oil underneath...and boy oh boy I wish I had taken a video of the exhaust when I took off down the road....let's just say I'm pretty sure no one saw the sun shine that day anywhere in the state....even though it was a clear day...

[bigred]

Just like every 2 stroke in the truck stop back in the day.

We just didn't notice, since the trucks rolled coal while they moved too...

happy coaching!
buswarrior

Years ago when I worked for a small truck line ,we had an old L J that rolled coal every time we changed gears.Used to be our only amusement since there were no radios,no stereo's or C B 's,to find some body walking along side the road, time it just right when the exhaust pipe was even with them and change a gear'. Boy!!We were a mean bunch back in those days!!!lol

[Geoff]

Something that happens when idling the 2-stroke Detroit is that you have very little oil pressure at 500-600 rpms.  The last thing to get oil are the rocker arms.  I
Excessive idling wears out the rocker arms pins from lack of oil and of course there go your clearances.

[Dave5Cs]

Great advice Geoff thanks.