Oil Question

[philipk65]

I have a '49 Ford F-1 with the original flathead in it. My question is what should I do about oil with this new problem with today's oil not having the right amount of zinc and phosprous in it (ZDDP)?

[19tom40]

IMHO nothing.

My reasons are that the flat-head engines are slow revving engines and there is not the extreme pressure on the valve train as there is in the more modern engines. A stock cam and lifters should last a long time with the low mileage and low stress on these engines.

There were a series of articles in Skinned Knuckles last year on this problem. They are good reading and help explain why you should do nothing and what to do if you are still worried.

Any oil that has an API rating of SL will have enough ZDDP to protect engines that are susceptible to cam wear. Oil made for diesel engines and some speciality oils meet these specs. Kendall GT-1 High performance oil is another oil that meets the SL specification.

[19tom40]

I have been informed that STP has enough anti wear additive to replace the ones left out of oil with an API rating of SM

[philipk65]

Thanks!

Is that STP oil treatment?

[19tom40]

Yes.

Read the newest article in Old Cars Weekly about the new oils. Adding too much zinc can cause other problems.

I would still do nothing and continue to use modern oil.

[bill pritchett]

Note, that the Mobil 10W30 conventional oil still goes back to SG as of today when I was in Walmart.