My understanding is that they have removed zink from motor oil because it clogs catalytic converters. Zink works very well on engines with solid lifters and tappets. It is a well known fact that modern engine use roller tappets and lifters because of the lack of zink in modern oils because it clogs the cats. Now that diesels have to be tested for emissions they do not put zink in diesel lubricants such as Standard Oil's RPM DELO and Mobil's DEL-VAC. What are you using to control the rubbing friction on your Model T engine now that no modern oil will protect your friction issues ?
There are lubricating oils containing zink made for older engines and small bottles of additives containing zink to put in your modern oils that lack ZDDP. The maker of a well known older engine oil replacement containing zink states that the zink additives do not hold in suspension and do not get distributed until the engine warms up. They state that the most wear happens at cold start-upnd it is best to purchase a homogenized oil containing zink rather than using the additives. The R.P.M. DELO and DelVac no longer contain ZDDP.
I recently purchased some 20-50 multi-lube oil from the Fischer Company. It is being sold by some Model T Suppliers at this time. It is packaged in three five liter bottles to the case. It contains between 1200 and 1400 ppm (ZDDP) anti-scuff molecules. and is S.A.E. rated as API-SL/CD.
Our 1906 Moline and 1913 Cadillac had roller cam followers because of the friction issue but Henry used rubbing friction lifters and cam followers without rollers. Did he make the metals strong enough to not require zink because I don't think they had zink in olden days? So perhaps it is not an issue with a Model T. What say you ? Remember that we sometimes replace our old original Henry lifters with modern ones that may have different metals in them which may require zink.
Boy do these Model T's get technical at times ;~}
I don't believe Model T spring pressures present a real problem, zinc or no zinc.
Jerry you may be right. the case label says for engines made prior to 1993. I know that T's didn't use oil with zink back in "the day".
It's a non-issue for your broken-in T engine and much overrated in the wider old car world. If it was the issue they say it is (and "they" are usually the ZDDP or specialty oil suppliers if you dig deep on the source of articles), you would see cars dropping from cam failure left and right.
The main place it is a concern is on a newly rebuilt engine where the cam and lifters have yet to seat to each other, this being more of an issue as performance increases.
I don't think roller rockers or roller cam followers have any thing to do with zinc. They sure weren't used because it was or wasn't in the oil.
Actually, it is. There is a very good ASME paper on the subject. This whole ZDDP thing started in the 1980's when catalytic converters came into heavy use. As mentioned above, the zinc in the oil didn't agree with the cats -- easy answer: remove the zinc! Then they noticed an increased rate of cam failures and found it to be directly attributable to having removed the zinc from the oil. There again -- easy answer: do away with flat tappets in favor of rollers.
Rollers are nothing new, but they were cost prohibitive compared to engine life and production expense early on. Buick's had rollers at least as early as 1932 and other better cars earlier than that.
I recently had to replace my cam and lifters in my MGTC... they had worn flat. I've used Delo on that car for years... but who knows what was used previously. When I did the work I found extra heavy "racing" springs on the valves.
The geometry of the flat cam against the cam is similar on the T. I suspect the same thing could be happening in our cars, but probably at a much slower pace. The engine in the MG is a 1947. The parts shown were original parts and probably few of our T's are running original cams and lifters (my guess based on no firm knowledge!).
Oops, I meant "flat lifter against the cam".
Compare the cam lobe at the top of the photo with the two next to the gear.
Perhaps this photo better shows how the cam can wear down... this came out of a running car (my MGTC)! It runs better now! The lobe at the center of the first picture is how it should look, compare that to the lobe just in front of the gear in the second photo!
Any car that has valve spring pressure in excess of perhaps 75 pounds closed / 300 pounds open and uses flat tappet lifters needs a good quality oil with ZDDP. Those are typically engines built after about 1955 in the USA. The Society of Automotive Engineers found that ZDDP additives in motor oil helped reduce camshaft lobe wear and made it a warranty requirement for new cars of the mid - 1950's era. Thus the oil companies were forced to add it to motor oils beginning in the middle of Eisenhower's administration.
No model T ever had ZDDP in its oil until at least 1955, because oil made before that did not have ZDDP.
Stock Model T valve spring pressure is ridiculously low, on the order of 10 pounds closed and 15 pounds open. There is no place in a Model T engine that benefits from using an oil with high ZDDP content. It won't hurt anything, but won't help anything either.
Frank's blue racer might have valve springs that need muscle car era oil, but I doubt it. Those kinds of spring pressures were way outside the norm for anything less than a fighter aircraft prior to 1955.
The extra heavy springs can make a difference, particularly if the remaining components aren't suited for the application. Very few of those things have an engine that hasn't been modified. There have been heat treat issues with lifters coming from overseas. All sorts of stuff that can cause problems like that.
ZDDP did not even come on the scene until the 1940's, and after that it's content fluctuated to modify oil for different purposes. Anyone who wants to know ought to read that paper I referenced above. There's no one size fits all with zinc. Too much can cause problems too, which I think is why it's interesting that manufacturers of these additives say you can just dump in a bottle of this or that and your problems are solved. You may be creating new ones. Its content level is a fraction of a percent.
At the speed a Model T engine runs who the heck needs 100 pound + valve springs?
The increased pressures are to prevent float....not to ensure closing at Model T speeds.
To my understanding, Zink is not an ingredient removed from oil. Zink was added in the 50s for better lubrication. I was then removed in the 70s along with lead for emissions. The T engine was not designed for zink and so i think little benefit would accour if you ran zink in it.