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Oil for '48

Friend of mine has a '48 1/2 ton with the 216 that she wants to get back on the road. Last run about 10 years ago.

I'm wondering what oil to use in it.

Issues:

(1) It has a glorified splash lubrication system for the rod bearings-- if the viscosity is too high they're not going to get lubricated right.

(2) Flat tappets, not roller, so should have a good deal of ZDDP--I'd rather waste 10 bucks on an additive than have to replace the cam.

(3) The "book" says to use SAE 20 unless the temperature is going to be sustained above 90.

(4) Starting in 1955 Chevrolet was recommending 10w30 as an alternative to 20 weight.

Most oils on the market today have had the ZDDP cut down from their levesl 10 years ago to protect catalytic converters.

So the plan is to use a good 10w-30 with the addition of a zddp additive. I?m wondering if anyone knows of another alternative, or a reason that that?s a bad idea.

I'm aware of "classic car" oils such as Castrol 15W-50. Might be fine for "classic cars? from the ?60s but I think it?s going to be too heavy for the rod bearing lubrication system on this engine to work properly.

Anyone tempted to say "let the chemists do their job" must bear in mind that the zinc limits are set by bureaucrats, not chemists, and the chemists generally are not testing for compatibility with 60 year old engines anyway. And anyone tempted to say that they didn't have ZDDP in

1948 needs to do more research.
Reply to
J. Clarke
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sounds like a good plan. One question though. How does oil affect a catalytic converter?

Reply to
Troy

Any phosphorus that gets on the converter poisons the catalyst so the conve= rter doesn't work anymore. A tiny amount of oil gets into the cylinders, s= o if there's phosphorus in the oil a little bit of phosphorus gets in the e= xhaust. I don't know if it's a real problem or just bureaucrats being bure= aucrats, but we all have to live with the result.

Reply to
jclarke

converter doesn't work anymore. A tiny amount of oil gets into the cylinders, so if there's phosphorus in the oil a little bit of phosphorus gets in the exhaust. I don't know if it's a real problem or just bureaucrats being bureaucrats, but we all have to live with the result.

Well, planned on getting some 10w-30 Rotella T at Wally World. They don't have it anymore, but they do have 5w-20 Quaker State Defy which according to the label has increased levels of zinc. Googling, I found a third-party analysis and it does indeed have increased levels. Problem solved for cheap.

Reply to
J. Clarke

15 50 will be fine. When cold it is no thicker than a 15 weight (lighter than 20) so you will be fine there, and when hot it does not thin out as much as #20 - so you get better hot lubrication and less oil burning as a bonus.

Another alternative is 4 stroke motorcycle oil - which generally has higher ZDDP levels.

Reply to
clare

If the engine burns oil, and the oil contains zinc or phosphorous, it kills the converter. Simply consuming too much oil can also cause a converter to fail by overheating it - same as running too rich.

Reply to
clare

converter doesn't work anymore. A tiny amount of oil gets into the cylinders, so if there's phosphorus in the oil a little bit of phosphorus gets in the exhaust. I don't know if it's a real problem or just bureaucrats being bureaucrats, but we all have to live with the result.

I would look for something with a little higher base number for use in an early 216. I think you will see excessive oil burning with the

5W20 - just judging from past experience. I've worked on a lot of older engines - and owned a few (back as far as 1928)
Reply to
clare

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