The Endless Oil Debate

[moonwolf]

A Chevron rep conducted a class on modern oils for the members of my AMCA chapter last month

At the meeting, he gave me the email address of the Chevron Tech department, saying that they would be happy to address any and all questions about oil in detail.

According to the rep, a lot of the folk knowledge that surrounds oil use and applications simply isn't true. In addition, a lot has changed in the past few years. Now is your chance to put those cherished beliefs to the test or at least to get a response from an informed source.

So, if you have a question about oil, please post it here. Be as specific and detailed as possible. Next week I will gather the questions, consolidate and clarify when necessary, and send them to the Chevron tech guys. I am making the same offer on the antique and bobber forums, so consolidation will, no doubt, be necessary.

After they reply, if there are follow-up questions, I will glad to send them on.

I'd like this discussion to be as constructive and objective as possible. Please don't rail on your point of view. If you disagree with the rep's response, articulate your issue in the form of a follow-up question.

I will post the final questions and responses as a CAIMAG article. Now's your chance guys. Chime in.

[Bigincher]

Uh-oh. Here we go....!

Well Moonwolf, my friend MBF and I were discussing this the other day, whether to run a multivisc in our old Pans. We are in agreeance that back in the '50s the modern multivisc oils just weren't available, and now that they are, why NOT run them? As was pointed out here on this forum a short while ago (sorry, forgot who the author was), the 20/50 oil will run thinner when you want it to (cold) and "thicken up" when it gets hot. Man, I don't know how you can beat that.
We were also discussing how we used to run heavy oils, 60wt and even 70wt (bad idea) in the summer, but those motors clattered a little bit on cold starts. We know this isn't good, either, as the oiling system on a Harley relys on flow volume, not pressure, and that thick old heavy oil just doesn't flow when cold, but it will make the pressure guage (another bad idea) read real high, giving a false sense of well-being.
So we decided that a 20/50 designed for air cooled engines is what we will run, until we see proof that that is not a good practice.

These oil debates and discussion get real old real fast, so I wish you luck on your endeavor. I sure hope the discussion on synthetic oil doesn't rear it's ugly head and detract from your noble effort.

[MeanGene]

Originally Posted by Bigincher

Uh-oh. Here we go....!

Well Moonwolf, my friend MBF and I were discussing this the other day, whether to run a multivisc in our old Pans. We are in agreeance that back in the '50s the modern multivisc oils just weren't available, and now that they are, why NOT run them? As was pointed out here on this forum a short while ago (sorry, forgot who the author was), the 20/50 oil will run thinner when you want it to (cold) and "thicken up" when it gets hot. Man, I don't know how you can beat that.
We were also discussing how we used to run heavy oils, 60wt and even 70wt (bad idea) in the summer, but those motors clattered a little bit on cold starts. We know this isn't good, either, as the oiling system on a Harley relys on flow volume, not pressure, and that thick old heavy oil just doesn't flow when cold, but it will make the pressure guage (another bad idea) read real high, giving a false sense of well-being.
So we decided that a 20/50 designed for air cooled engines is what we will run, until we see proof that that is not a good practice.

These oil debates and discussion get real old real fast, so I wish you luck on your endeavor. I sure hope the discussion on synthetic oil doesn't rear it's ugly head and detract from your noble effort.

That would've been me- think of it this way, pour some 20-50 while it's hot- that's the normal running condition, warmed up. Try the same thing with straight 50- it'll pour just the same- while hot. Do the same thing cold, the straight 50 will flow like molasses, but the 20-50 will flow like 20w, giving you much better protection when it's cold. If it's gonna leak, it'll leak- mostly while it's warm anyway. If it's leaking cold sitting still, you just need to get off yer butt and work on it LOL. Startup, before oil pressure builds up, is when most wear occurs anyway, why add to it by running another 10 minutes with oil that will hardly flow? Just because it's been done for 40 or 50 or whatever number of years (when nothing better was available) or because Father Moses said so is just not a good reason to keep on doing it.
The whole syn thing makes me laugh, the almighty "Genuine H-D" line was that syn was the devil incarnate, bearings will slide, engine will grow tumors, first born kids gone, right up until the "Genuine H-D" syn was introduced, and magically was the savior, even though everyone else's syn was garbage LOL

[moonwolf]

That seems to be a big one, Tom. Another way of putting it, I suppose, is simply what is the best oil to run in an old or antique air cooled motorcycle and why. Your question is definitely on the list.

As for STP and Teflon additives, the rep told us to stay away from them. Modern oils have everything you need. STP, according to him, is pure viscosity enhancer--in other words, it just makes the oil thicker. I think, though, that this question should be included so the chemists can give us a definitive answer.

The rep we talked to said the same thing as meangene--20-50W oil is fifty weight oil when it's hot. It cold pumps much better and most engine damage is done at start up.

As for the motor company oil, it's put up for bid periodically. The contract goes to the lowest bidder, so there's nothing magic about the brand.

[Bigincher]

Moonwolf, I don't know if it's really a question. I'm with MeanGene all the way on this one. Someone will have a hard time of it convincing me (and MeanGene, too, no doubt) that multivisc is bad for a vintage air-cooled motor.

[moonwolf]

In the seminar I attended, the rep assured us that a multi-viscosity oil was, in fact, the best thing for our bikes. If I suggested otherwise, I misspoke. He also said that the lab guys know far more than he about such things and suggested I send them our questions.

The question I'm hearing, though, is about hot weather. Since no one I know of makes a 20-60, is a 20-50 adequate for an air cooled (and ancient bike) in hot weather?

[Bigincher]

Originally Posted by moonwolf

In the seminar I attended, the rep assured us that a multi-viscosity oil was, in fact, the best thing for our bikes. If I suggested otherwise, I misspoke. He also said that the lab guys know far more than he about such things and suggested I send them our questions.

The question I'm hearing, though, is about hot weather. Since no one I know of makes a 20-60, is a 20-50 adequate for an air cooled (and ancient bike) in hot weather?

Didn't mean to imply you said anything different, Moonwolf. Not at all. I wonder if you can mix 3 qts of 20/50 and one qt of straight 70, and end up with a 20/55 or 20/60 or some such. I would ask that question.

[MeanGene]

I'm of the opinion that there were only two reasons folks used straight 60wt- mythology passed on by old-timers that it was "better", and an attempt to keep the oil on the inside of leaky bikes- JMHO, neither reason is valid.
We used to run straight 50 weight (real) racing oil in the sprint car (given to us by the sponsoring speed shop), but it also had a heating element built into the 12 qt dry sump tank- as soon as the car rolled out of the trailer, it got plugged in- she was ready to rumble with hot oil when it first got fired.

[moonwolf]

Originally Posted by MeanGene

I'm of the opinion that there were only two reasons folks used straight 60wt- mythology passed on by old-timers that it was "better", and an attempt to keep the oil on the inside of leaky bikes- JMHO, neither reason is valid.
We used to run straight 50 weight (real) racing oil in the sprint car (given to us by the sponsoring speed shop), but it also had a heating element built into the 12 qt dry sump tank- as soon as the car rolled out of the trailer, it got plugged in- she was ready to rumble with hot oil when it first got fired.

That's my opinion as well, but I'm wondering about the higher temperatures our bike run. A modern car motor runs more than a hundred degrees cooler than an air cooled bike. I'm wondering how that heat difference affect the characteristics of an oil, including viscosity.

[Perry]

Since no one I know of makes a 20-60, is a 20-50 adequate for an air cooled (and ancient bike) in hot weather?[/QUOTE]

I'm running Red Line 20-60 in my Pan. It seems to work well.