ZINC FOR ENGINE BREAK-IN

[oilcan]

I have been reading on the Ford Forum about getting flat lobes on cams at break-in due to lack of ZINC in todays oil. I'm having a real problem understanding how a lack of Zinc causes a flat lobe not all lobes just one.
Can someone help me get some kind of grip on this situation.

 

[mechtech]

Once you get through the surface hardening, wear is real fast. Some lobes may not get initially oiled as well as others.

 

[wileyE]

what engine? sound more like a design issue to me?

 

[unDummy]

Improper break-in and not using good ol' assembly lube causes most problems. But, its always easier to blame the oil and not the clown doing the install.

 

[Hirev]

quote:

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I'm having a real problem understanding how a lack of Zinc causes a flat lobe not all lobes just one.

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In many motors the cam lobe is splash lubricated. Not all lobes get an equal amount of oil splashed on them because of motor design. Hence the importance of a good boundary lubrication such as Zinc.

Most cam lobe failures I have seen involved 1 to 3 lobes. This includes factory assembled, machine shop assembled, and back yard motors.

 

[CJWAUS]

John Deere used to have a powder you sprinkled in when you rebuilt an engine. I have no idea what the powder was, but now they have a designated oil to use after rebuilding an engine.

 

[ebaker]

Add a bottle of GM EOS for the first 300 miles or so. It contains 6000+ ppm ZDP. I've read that most cam lobe damage occurs in the first 15 minutes a motor is run. Get all the spark plug wires, timing, and fuel system in order so you can start the new engine an immediately rev it to over 2000rpm. The crank will throw oil onto the cam (assuming a cam in block motor)

 

[C4Dave]

This is why cam manufacturers recommend that you maintin 2000 rpm immediately upon start up.

 

[JohnBrowning]

ZDDP,moly and boron in generious amounts are good for break-in. Their is nothing that is going to keep asperitys from rubing! If it was just one lobe it sounds like a quallity control issue. If the heat treatment is not done properly this can happen. Normaly if it is a lubrication issue you would see gualling on the cam journal and the lobes would shoe signs of heat. You would also see were material was micro welding itself from part to part.