Oil Debate 101

[55 Fargo]

Hi all, was reading a detailed article about modern oils for old style engines with in the Winnipeg Free Press Auto Special Friday section today.

Now this article went on to discuss the absence of zinc maganese and/or phophates in modern high detergent engine oils.

This article discusses how modern oils absent in ZDDP can cause cam lobe and tappet wear.

This article states to look for oil with SL or SJ ratings, here are a few oils they recommend Redline Street blend oils, Amsoil 20W50, Valvoline VR-! 20 W50, Castrol Syntec 20W50 High Zinc Formula oil.

Would like to start a discussion with this, I am currently using Shell Rotella T 15 W 40 motor oil in my 47 Chrysler flathead 6................................Fred

[bobby horne]

I have been using the rotello oil in my 38 plymouth with a 36 engine for several years.....So far very good......

[55 Fargo]

I agree this is great engine oil, is the formula still the same, will it be absent of the necessary ingredients we need for long engine life in our flatheads...............Fred

[Normspeed]

My first plan was to use Mobil 1 in my fresh motor, but after considering that article about zinc I ended up using Rotella T 15w40. If I rebuild another one I'll use Mobil 1 and let my descendants determine which was better.

The zinc additive is probably more important with heavy competition valve spring setups but I'll go for it anyhow even with my stockers. I think that most modern oils are much better than what we ran in the 50s and 60s in these cars. Bulk oil anyone?

[Don Jordan]

I was told that in my Toyota I had to use a multi grade oil. No problem. But since I'm an old timer I use straight 30w in the Plymouth. I've never seen the oils you guys mentioned. Where do you get it. I've been using Penzoil and it seems to work.

[central52]

Where can you buy a can of that ZDDP additive to add to the engine oil? Ed P.

[Flatie46]

A few years ago I built a perfomance Harley engine, a mechanic friend told me he recomended the valvoline vr oils to break it in then switch to synthetic he said synthetic was so slick it would not allow the rings to seat during break-in. I think I'll try this on my re-man flathead If I ever get it in mycar:rolleyes:

[James_Douglas]

The zinc story is BS with no science behind it. I have a friend that works for Standard Oil and has talked with the person that runs the tests for them and GM on oil.

They use a flat tappet engine in-line-six with their oil tests, very controlled tests, and they don't have any evidence of premature wear.

However, there is strong evidence that a good many flat tappet lifters in the last 8 years are being made overseas and are not falling within the required Rockwell hardness of about 48Rc to 58Rc.

Soft lifers will die and kill the camshaft. I would worry about that and not the oil. Save your money.

James

[FMSPEED49]

From what I understand the Rotella has the zinc we are craving.

[Captain Neon]

I'd rather be safe than sorry. I'm not the mechanic many on this forum are. I've been told that my 230 MoPar L6 has hardened valves and seats, but I still use tetraethyl lead & sodium-based lead substitute additives in my fuel. If nothing else, the lead gives me more octane and the lead substitute helps to clean my fuel system.

I have been using Havoline my whole life, but, at least for my P-15's 230 L6, I will begin using Rotella T 15w40 this spring. The cost difference is insignificant. In fact, I think the Rotella T may actually be cheaper than Havoline. Everything else is running on Havoline.

[wayfarer]

The diesel oils, Rotella and Delo 400, et al, still have more of the ZDDP than others but they have seen some reductions. Use the diesel oils. If that 12L Cummins likes it then I figure it will be good enough for my puny gas rigs. As far as the offshore lifter issues continue, and the issue will continue, then be sure to buy yours from a reputable source who actually cares.....there is way too much garbage quality offshore crap landing in our country, but as long as we continue to buy it, the stores will continue to stock it!!

[Guest rockabillybassman]

Rotella is having the ZDDP removed this year. Huge threads, and many experts, at the Hamb have concluded that our engines will not be adversely affected by the loss of ZDDP. The engines that have been failing are mainly newly built SBCs with replacement cams ground from chinese billets. As stated above, they do not have the Rockwell hardness of American billets, and have been failing in a few hours. Seems that unless your engine has chinese parts in it, there is nothing to worry about.

I dont care if it is un-PC.... chinese anything = crap!

[greg g]

The failures have also been related to HD valve springs in built engines. I do not think our engines are in that catagory. I have been running the diesel oil from tractor supply company in my fresh 230. But I am running the good old stock cam, lifters and springs. 5K so far so good!

People running race engines on the street don't make a lotta sense to me. They always seem to be the ones breaking.

[Furylee2]

I read this thread, and the big discussion in some of the others, and I’m interested in trying the diesel oils in my 41. When I was in Wal-Mart, I didn’t see anything made specifically for diesels in all their brands of oil. Can someone tell me the names/brands that I need to look for? Thanks, Lee

[Captain Neon]

My local Wal*Mart has both Rotella T and Delco 400. Try your local tractor supply store if your Wal*Mart doesn't carry Rotella T.

[David Mac]

This question is related to the rotela 15W40 oil, but not about wear. Does anyone know if using the heavier weight oil makes your oil pressure rise?

[Normspeed]

It might raise the oil pressure a little on a worn motor. At operating temp, it's a 40 instead of the good old 30 single weight. The big advantage is the 15w part, meaning at cooler temps it's not as thick as 30W and flows better before the motor is warmed up. Best of both worlds.

Your pressure relief valve will open at a preset pressure regardless of how thick the oil is.

[David Mac]

Thanks Norm for the info. The reason I was asking is that my oil pressure runs between 40 & 70 at temp on a rebuilt engine. Is this too high? and if so could this be the cause of my rear seal leaking (new seal)?

David Mac

[Normspeed]

Might be a sticking oil pressure relief plunger. I think Don C had that happen not long ago. The plunger usually opens around 40 PSI. I'd think 70 would be too high. I don't know if it would cause a rear seal to leak. These old motors love to leak there.