API 'SM' Oil - no zinc... don't use in old engines?

[oz]

I just saw an article in Mustang Monthly about how API Grade 'SM' oil has no zinc in it and therefore is not suitable for our flat tappet equipped engines....
I checked my stock of oil and found 4 bottles of 'SM' - the rest is all 'SL'... not sure if the missing 8 quarts of SM went in the '69 or the '91... probably both.

I ordered a case of ZDDP Plus but has my head been in the sand or is this a pretty new development?

The engine in the '69 has been rebuilt and warmed up a bit so I plan to hold off driving it until after I add the ZDDP.

Any comments?

 

[rbohm]

even though zddp has been removed from motor oil over the years, the oil companies are replacing it with other anti wear additives.

 

[oz]

So you're saying we have no worries???

 

[rbohm]

not according to the oil experts. i think the incidents of cam failure has declined in recent months, and they were not that prevalent anyway. same with the problem of valve recession when leaded fuel was removed from the market in the 70's.

 

[brianj5600]

What are the additive they use to protect against metal to metal contact? I wonder if the decline in failures has to do with the education on oil and flat tappets. I lost a cam before switching to diesel oil. I don't want to to take a chance just yet on current auto oil. The money to change cam and lifters is not worth the risk. Comp has not removed their bulletin yet. http://www.compcams.com/Base/pdf/FlatTappetCamTechBulletin.pdf

 

[hipo_p51]

my engine builder mentioned this zinc issue to me when i received my motor. he recommended kendall oil. appearently that brand still has zinc in it.

 

[oz]

My undestanding after reading the article in Mustang Monthly is that API Grade 'SM' has NO zinc in it at all and should not be used without a ZDDP additive in flat tappet engines such as ours.....
So, when I buy oil, I am going to make sure I get 'SL' as long as it's available.
Once it's all gone, I'll be using the additive.
Since I don't know if I have SL or SM in the engine now, the car will stay parked until the 6 pack of ZDDP Plus that I bought on eBay arrives.

 

[Decurion]

I remember a rep from Valvoline being on one of the sunday car shows not too long ago and saying that a flat tappet cam should not be broken in with a non-zddp oil. He said that once its broken in it should be fine, but didnt sound very confident in it either. Personally I would break it in on an oil "not intended for street use" for maybe 1000 miles, then use regular oil with a cheap zddp additive. Ive found the o'reily zddp additive for something like $2 a bottle, so its not that expensive. Im not looking to relive this:
View attachment 254259
View attachment 254260

 

[oz]

Im not looking to relive this:
View attachment 254255
View attachment 254256

Holy crap!!! Nobody wants to relive something like that. Did the metal shavings plug your oil filter or get into the rest of the engine? I bought ZDDP Plus online - it was expensive ($8/bottle) but I figure it's good insurance. I'll look at the O'Reily's stuff too.

I readjusted my rocker arms a couple of months after I broke in the newly rebuilt engine and the lash had not changed at all so I think I had sufficient lube at that time.

 

[Decurion]

I dont know if anything happened to the rest of the engine since I havent torn it down yet and likely wont for some time since its on the back burner for now and doesnt run anyway. I think it happened on break-in, but since I had so many other problems with the car, what seemed like a rocker arm that kept coming loose didnt really get much attention. It always had great oil pressure right up to the day I started taking it apart, though it did run rough and began to backfire. I think both were on exhaust side, IIRC. For what its worth, Ill be replacing this with a roller cam when the time comes.

 

[zookeeper]

I use Valvoline Racing 20W-50 since it has ZDDP in it. Maybe I could get away with something else, maybe not, but why take chances?

 

[tx65coupe]

I have never heard of this ZDDP stuff until recently. Does it have any benefit for a 302 roller motor? I have a 90 302 in my 65.

 

[Hack]

I have never heard of this ZDDP stuff until recently. Does it have any benefit for a 302 roller motor? I have a 90 302 in my 65.

ZDDP will benefit any MOTOR, but it's hard on catalytic converters. The EPA wants cats to last as long as possible, but they don't care how long the motor lasts. Forget about the fact that building a new motor/whole car takes a lot of energy and resources..

Typical environmental nazi shortsighted and backward thinking, IMO.

 

[oz]

Yea, I was thinking of putting part of a bottle in my roller cam cars (no cats) as well.... just as additional insurance.

This, for once, sounds like a beneficial oil additive that should be taken seriously.

 

[rbohm]

ZDDP will benefit any MOTOR

while this is true, it has less benefit for a roller cam motor than a flat tappet cam motor. as for adding zddp, it wont harm anything, except perhaps the cats if you have them, and of you feel comfortable using it go ahead. same with choosing an oil that has zddp in it.

 

[SadbutTrue]

anyone got a summary of what the hierarchy of oil API ratings are? my motorcycle also requires a certain grade and i want to make sure I get it right, but a lot of the time they just give a 'minimum' grade (which means nothing to me)... so I don't know what other oils may work and which ones wont. if something ike that exists it'd be great...

 

[brianj5600]

Google is your friend.

 

[RGS0907]

There is info out there

ZDDP has been cut down alot but there still is some left in most oils, even SM. Diesel Oil has enough of it & lots of people use it, so does most racing oil. It isn't as important when your engine is already broken in, but it can trash your lifters in a new build.

Mobil-1 has a chart of what is exactly in their oil on their website. I'll try to post it tomorrow. Also, here is a website, telling you everything you ever wanted to know about motor oil! Some people have no lives (including me).

Bob Is The Oil Guy - Powered by Motor Oil

 

[65ShelbyClone]

I too have noticed that there doesn't seem to much issue with using the SM oils with slider valvetrain that has already been broken in. If I was breaking in a slider cam, I would opt for a high quality racing oil or use a ZDDP additive. So far, my SVO has been working fine on diesel oils, but I use regular Chevron 10w-30 or 10w-40 in my '94 Toyota truck with no ill effects.

my motorcycle also requires a certain grade and i want to make sure I get it right, but a lot of the time they just give a 'minimum' grade (which means nothing to me)... so I don't know what other oils may work and which ones wont. if something ike that exists it'd be great...

Lots of motorcyclists(myself included) run the same diesel oils that some of the slider cam crowd have gravitated toward lately. I just got done buttoning up the top end of my Honda XR600 and the inside was spotless and the parts are all wearing very well. Many people will still say you're crazy for "risking" your engine on anything but what the factory says to use, though. It's a judgment call in the end.

 

[jcp123]

Shell Rotella has a decent amount of ZDDP in it, and Redline synthetic does as well. STP Oil Treatment also contains ZDDP, but it's more a stopgap than a true benefit - I'd go straight to one of the aforementioned oils, as a full bottle of STP won't significantly raise your total ZDDP count. I'm going to run the Rotella 15w40 I got for free from work and then get some Redline.