Zinc in Oil

[48mirage]

Turning through the channels this afternoon and came across a PBS car show. They usually highlight the higher end new models but they had a segment on Zinc in oil with a "lubrication engineer". Knowing this had been an item of discussion before, I tried to listen as best I could.

This fellow stated that the zinc was not added to oils until the late 50's and then at about 300 ppm. That number went up to about 1800 ppm before the catalytic convertor became an issue. He did go on to say the only ones who should have a concern about the lack of zinc are us flathead users. His solution was to use a racing oil during breakin and then use any modern oil.

FWIW

[Don Coatney]

He did go on to say the only ones who should have a concern about the lack of zinc are us flathead users.

Flathead or flat tappet?

[Plymouthy Adams]

I post this info a while back..straight from the Crane camshaft website

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=7711&highlight=zinc

[n1gzd_plymouth]

I use shell rotella because it still has the zinc. They removed it from their other oils.

Rebecca

[Normspeed]

I use the Rotella T. It was a toss up between that and Mobil 1 synthetic. Time will tell.

[teardrop puller]

Any one have an idea about the full synthetic Rotell T?

kai

[greg g]

If you listened carefully it was flat tappet engines with newer cams during the breakin period. The new cams are infected with chinese disease (dragon ass) actually recycled steel. This stuff probably has worse metalurgical science than when the originals were made. The issue is wearing new cam lobes out (or flat) during the breakin period of newly rebuilt engines uning new modern junk cams.

Oil rated for HD diesels still contains the zinc phosphorus addtives if you are running a new cam. Otherwise, I don't believe this is a great concern for our vehicles.

[Plymouthy Adams]

Greg..it is not only modern junk chinese made cams..is is all cams with surface to surface contact where galling can and will take place. The modern engines of today are pretty much roller lifter design and have done away with the scuffing action. The biggest killer of cams is the guy who puts a high lift cam in and higher compression rate springs and thinks that he can just start his engine and all is well..further he decides it is so super cool to hear it chop..now for the small block this is not as drastic but for the larger V8 etc the cam will have to be close to 290 degrees for you to hear the chop...the profiles of these cams have fast ramps do not lend themself to street use per say and even less for substained idle..if in the event one should feel that he needs build an engine this way..do assemble with molybendenlymdisufide and use the lower rate stock passenger car valve springs to break in the cam and lifters..afterwards if you be racing and KNOW you will need the high rate springs to prevent float..then install them..I know a guy who has put 5 cams in due to the fact he refuse to believe rate of springs at break in is significant..oh well..his money...