What causes roller lifter pitting?

[mtocrs1]

What causes this? Will these just continue to disintegrate? These were only supposed to have 500 miles on them.


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[delcowizzid]

skidding on the cam lobes instead of rolling or bouncing off the cam and hammering back down from not enough spring whats the cam look like

 

[Nick Micale]

Is this representative from the owners that think a roller cam does not need an EP lubricant or ZDDP like a flat tappet does, and they may use synthetic oil which does not have enough additive to protect against the higher roller spring loading?

Solid rollers are also subjected to even higher spring loads and especially the small needle bearings must have proper oil/lubrication or they will go away.

If a roller skids on the cam at all it is done almost immediately, and with a ductile roller cam temper process could have been uneven or flawed so the cam surface could have flaked?

Someone posted recently to use oil that is as light as possible, but our thinking is just the opposite, especially since our engines are a 50 year old design using materials from that era as well.

Sorry for your mis-fortune as the cam will also join your display of spent parts.

 

[delcowizzid]

1st question is it only the one or all the intake rollers or all the exhaust rollers.did it run synthetic oil

 

[Nigel]

Nick, just to be clear you recommend ZDDP even with a roller? Thanks.

 

[mtocrs1]

So, I bought these as sort of a package deal with a modded ECM. I bought them cheap enough I was willing to take the chance on them. I was really just asking the general question. I have seen this multiple times and always thought WTF.



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[mtocrs1]

Now my next question. I am installing a new roller set up soon. If this can be caused by the roller skidding should I use assembly lube on the cam lobes and lifter rollers during assembly?


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[TurboBuRick]

Is it actually pitted or on the surface? Is it possible that particles are stuck to the wheel? Any other rollers look like that? Hows cam look?

Rick

 

[mtocrs1]

I have no idea how the cam looks, I didn't purchase it.
I can't feel anything, they are smooth to the touch.
A few of the others look this way but less severe. This one is the only one I could get a good picture of.
I will have to go back and check but I think only one roller out of a pair has this, indicating either it was on the exhaust or intake lobes only. Must have been some sort of setup issue.


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[delcowizzid]

one on each pair will be too soft of a spring under boost its quite easy to loose 40Lb or more of spring pressure when you have boost or backpressure trying to open the valve.i bet if you had the cam its probably got the same pits on the closing ramp side of the lobe tip where its lifted off and sat back down

 

[bison]

500 miles a quarter at a time and inadequate spring pressure


BPE2013@hotmail.com

 

[earlbrown]

More cams have been destroyed with too little spring pressure than the other way around.

 

[Ttype6]

Nick, just to be clear you recommend ZDDP even with a roller? Thanks.

He sure does,but take note that he did not recommend that you add the ZDDP to your inadequate oil. Buy oil that already has an adequate amount. Every part inside your engine is subject to higher and higher amounts of pressure as power goes up. You must use stronger and stronger oil to push back against those pressures.

 

[750H.P.V6]

It looks like fatigue spalling to me not pitting. I agree with Brian and Earl it's caused by inadequate spring pressure and the lifter bouncing off the lobe.

Neal

 

[Mike Licht]

Yep liter bouncing instead of rolling not enough spring