The ultimate 2.3 roller camshaft

[Wizard191]

Finally found it again:

"Under pressure from the major Detroit automakers, the engine oil manufacturers have removed the zinc additive from engine oil. The really bad news is that this increases camshaft and follower failure rates enormously during the break-in time. If you can find a zinc additive for engine oil, that helps greatly. GM's EOS break=in lube has been a faithful option, too. I have heard that the Valvoline racing oil that's labled "not for highway use" may still have the zinc in it. Napa has made a commitment to keep this oil in stock.

There have been no changes in camshaft or follower materials or heat treatment from ANY of us in the racing aftermarket. The increased failure rates are due to the missing zinc in addition to the usual assembly related problems we've been discussing the last thirty years or so. Keeping open spring pressures as low as possible is now more important than ever."

from http://www.lazercams.com/

[svobrown]

What does the zinc do for the wear of a cam shaft.

After the search.

Zinc is the amount of zinc used as an extreme pressure, anti-wear additive. The zinc is only used when there is actual metal to metal contact in the engine. Hopefully the oil will do its job and this will rarely occur, but if it does, the zinc compounds react with the metal to prevent scuffing and wear. A level of .11% is enough to protect an automobile engine for the extended oil drain interval, under normal use. Those of you with high revving, air cooled motorcycles or turbo charged cars or bikes might want to look at the oils with the higher zinc content. More doesn't give you better protection, it gives you longer protection if the rate of metal to metal contact is abnormally high. High zinc content can lead to deposit formation and plug fouling.


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[svobrown]

more on zinc.
and where to get it.
zinc: good for the common cold & your car's engine

Another type of additive is zinc dialkyldithiophosphate. Zinc-d is found in Mechanics Brand Engine Tune Up, K Mart Super Oil Treatment, and STP Engine Treatment With XEP2, among others. The touting of zinc-d as a special ingredient in engine oil additives is a little like the Shell ads which touted "Platformate." (Most gasoline has similar additives but under different names.) Zinc-d is an additive in most, if not all, major oil brands. The wonder oils just put more of the stuff in a 50 weight engine oil. It would be useful if your engine were ever operated under extremely abnormal conditions where metal contacts metal: "the zinc compounds react with the metal to prevent scuffing, particularly between cylinder bores and piston rings....unless you plan on spending a couple of hours dragging your knee at Laguna Seca, adding extra zinc compounds to your oil is usually a waste.... Also, keep in mind that high zinc content can lead to deposit formation on your valves, and spark plug fouling" (Rau).

If zinc-d is so good for your engine, why haven't oil manufacturers been putting more of it in their standard mix of oil and additives? Actually, oil companies have been decreasing the amount of zinc-d because the evidence indicates that zinc-d causes deterioration of catalytic converters.

The bottom line is that outside of the testimonials of happy and satisfied customers and the guarantees of company executives about the wonderful effects that studies have shown will follow the use of their products, there isn't much support for using oil additives. Of course, there are those millions of customers who buy the stuff: aren't they proof that these things really work? Not really. They're proof that this stuff really sells!

[Joe P]

Another cam grinder. Schneider Cams @ 619-297-0227