Do we need the Zinc additive in Oil for ohv, flat tappet small engines?

[Razorblades]

I read in another forum recently that most of the engine oil producers stopped using the "Zinc" additive in their oils because of requests from the automakers. One of the reasons being that it shortens the lifespan of the catalytic convertors. The poster went on to say that the removal of the Zinc additive was causing problems in the ohv, flat tappet small engines, such as the kind that most of us run in our mowers. He said that the oils that were rated to meet the "SJ and later" specs were the oils that did not have the Zinc additive in them anymore. He seemed to imply that we should not use any of the oils rated "SJ or later". Have any of you read or heard any info to support this claim? If anyone can shed some light on this topic, please speak up. Thanks, Razorblades.

[Lawn-Sharks]

I have read these articles and have seen with my own eyes the lobes of camshafts of mine & my friends race engines worn off because of the lack of this additive, My machinist explained it better to me thats why I use Rotella T in all of my flat tappet engines from now on because they are one of the only few that still have the zinc additive. Since i have changed over i have had no problems. I know that Rotella T is primarily used for diesel engines but it can be used in gasoline as well.

[AmsoilPower]

Amsoil offers a couple oils high in zinc. Also I included a tech bulletin regarding the oil. Hope this helps some.

https://www.amsoil.com/dealer/techservicesbulletin/TSB_Flat_Tappet.pdf

www.amsoil.com/redirect.cgi?zo=1521372&page=storefront/amo

www.amsoil.com/redirect.cgi?zo=1521372&page=storefront/aro

[lubricity]

You don't need the ZINC. It is just another internet load of bull. One point you made but didn't realize. ALL "S" oils are crap and don't have a good additive package. If you buy an oil that contains the "C" rating, if will protect your motor. ZINC is old obsolete technology. It was discontinued in most industrial oil as well.

[B&A lawn care]

My gut feeling is the zinc deal might have merit in highly loaded applications such as the race engine example in the Amsoil posting. We used to run an additive package in our flat tappet racing engines for the break in oil only. Our mower engines do NOT have tappet loads anything like a flat tappet race engine. Specially oil Mfgs would sell little of their high buck products if their advertising lore said that the main benefit of using their product was putting more of my dollars in their pocket instead of resting in mine so personaly I'll take all of that "data" with a grain of salt.

You can punch up any oil, any engine on a Google search and find some board posting about how brand X oil will blow brand X engine in a matter of X seconds. So who ya gonna go with? Engine Mfgs have every reason in the world to get us to use the best oil for their product and have nothing to gain from a given brand outside of their own house branded oils (which usualy are a rip off of the same magnitude as the specialty lube companies)

I go with the engine Mfg specs and the nationaly known and distributed Mfgs like Valvolline Castrol etc and dont fret for a minute about lube failures,,,,,,,, and have none.

[Ridin' Around]

You don't need the ZINC. It is just another internet load of bull. One point you made but didn't realize. ALL "S" oils are crap and don't have a good additive package. If you buy an oil that contains the "C" rating, if will protect your motor. ZINC is old obsolete technology. It was discontinued in most industrial oil as well.

So how about all of the older cars that have flat tappet cams and need the ZDDP levels? You, I believe, need to do a little more research on this subject.
New Corvettes up to the mid 90's with LT4s need to have the higher levels. Some of the new oils are not backwards compatible.

[lubricity]

I have been selling and testing lubes for over 20 years. I know ALL the sales gimics to lure buyers. I'm not going to get into a Pi--ing match here. But all the companies bend the truth to suit their products. Believe what you want.
"Backwards Compatible" all the new oils, even the "S" oils are better than the previous or backward released versions.

[Den69RS96]

Lower levels of zinc can help contribute to a cam failure, but I doubt it will cause one. Cam failures can occur for many reasons. Radical cams with high lift rates requiring high pressure springs, improper cam break in, bad cam cores not hardened correctly, bad lifters, improper cam/lifter install. When I broke in my cam in my small block chevy, I used shell rotella t and bottle of comp cams breakin lube. I changed my oil after the cam breakin and used royal purple oil with another bottle of comp cams lube for extra insurance. Once I put about 1000 miles on the car, I'll just use straight rp.

For lawn equipment, just use a quality motor oil and change it according to the owners manual and your cam shaft should last a long time. I don't think you need extra zinc for a lawn mower

Here's a good read from another forum on oil

http://www.camaros.net/forums/showthread.php?t=122672&highlight=zinc