Idle Wear

[zoomie]

Read something from the 80's describing how idle wear on the cam lobes and bearings had been shown to increase when the engine is NOT loaded up (ie no torsion to raise the center a bit). I don't recall what type of cam follower used was hydraulic or not.

If your faced with cold climate conditions which necessitate prolonged idling, would todays dinos and synthetics make that test redundant and you could idle for hours without any wear and tear?

 

[Chris142]

Older v8 engines with non roller lifters don't get properly lubricated at slow engine speeds. Non issue with todays roller lifters.

 

[Astro14]

A lot of unknowns in your question...makes it hard to answer...

But, since you read it in the 80s, when most cars were domestic V-8/V-6 with hydraulic lifter OHV engines. On those kind of engines, it was typical to break in a new cam at 2000-2000 RPM, no lower or higher, to ensure good lubrication and correct lifter pressure...so...I suspect that it's no longer true...

 

[mechtech2]

Torsion to raise the center?
Do you mean the convex surface on a new lifter face that causes it to rotate?
On older V8 engines,it wears away to flat, then concave, even with old high ZDDP oils.

 

[SteveSRT8]

And in no way can you simply say that all flat tappet motors suffered from bad oiling at idle speeds!

Complete nonsense. The issues were more of a lubricant problem than an oil volume or pressure problem. And it would vary WILDLY by the type of engine.

 

[zoomie]

To raise the center of the camshaft bearing surfaces from drooping, when twisted it would raise allowing better clearance for oil. The bearing block of the idling engine had the majority of wear in the lower half while the loaded engines wear was more uniform around the bearing seat.

Whoever did this test used two of the same engine (a controlled test) and analyzed the surfaces with a microscope of some kind and showed pictures in their conclusions.

This was in a book I leafed through at a library, doubt its on the net.