Legendary Technical Editor Kevin Cameron explains motorcycle oils, from crude to synthetic and all the way down to the molecule. Co-host and Editor Mark Hoyer is mostly along for the ride on this one. Listen now as we get into the slippery subject of motorcycle oil.
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Listen on Spotify: https://open.spotify.com/show/6CLI74xvMBFLDOC1tQaCOQ
Search Cycle World Podcast on Apple
Read more from Cycle World: https://www.cycleworld.com/
Buy Cycle World Merch: https://teespring.com/stores/cycleworld
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00:00 Welcome to the Cycleworld podcast. I'm Mark Hoyer, Editor-in-Chief, and I'm with Kevin Cameron, Technical Editor.
00:06 We're back. We tend to talk about religious subjects occasionally. Motorcycles are a religion.
00:12 This topic is even more religious than religion. This is "What oil do I put in my bike?"
00:19 "What oil do I use for the whatever?"
00:22 This has been, I would say, the number one question, even back in the days of snail mail and getting letters mailed to the office.
00:31 It was, "What oil do I use?"
00:34 We want the elixir that saves us from anywhere at all, that makes our motorcycle last forever, make the most power, and just be as perfect as can be.
00:48 What do I do, Kevin? What do I do?
00:51 Motorcyclists want to refresh that new bike feeling regularly.
00:59 These people who are talking about wanting to make their motorcycle last 30 years do not persuade me that they are sincere.
01:11 I know that in two years, they're going to buy some new Whizbang, a wonderful model that has features we can't even dream of today.
01:20 The other one will go off to a new owner.
01:24 Making your motorcycle last forever, I understand the sentiment.
01:30 Basically, what we have to do is first choose oils that fall within the recommendation of the manufacturer presented in the owner's book.
01:44 Because each manufacturer, when a new model is produced, goes through an extensive process of oil proving in which they work out exactly what spec is going to give the best results with their product.
02:01 Now, is it likely that my buddy at the cycle shop is going to be able to give me a tip that improves greatly on what the manufacturer has discovered?
02:12 I don't think so.
02:14 But on the other hand, there's another consideration.
02:16 And that is, I've just paid 30 grand for some lovely piece of equipment.
02:23 And I worship it.
02:25 I remove every fleck of dust.
02:28 And I behold it.
02:29 I put on strong light to make it even more powerful an experience.
02:35 But what I want to do with oil is I want to do something for my motorcycle.
02:41 And I can sympathize with that.
02:43 We know that there are homeowners who put in plantings lovingly and expensively because they want to do something for what they have there.
02:55 And so, it used to be that the obvious answer was, well, you'll have to put synthetic oil in because that will enable you to pay $30 a quart.
03:05 Well, I can vouch for some synthetic oil options, particularly on the automotive side.
03:11 Vintage Jaguars with the four-synchro gearbox love a synthetic gearbox oil in either the 30-weight or 40-weight equivalent.
03:22 So, an MT90 or what they would call MTL, like manual transmission light.
03:28 Synchros, everything works better.
03:30 So, there is something there.
03:32 Oh, definitely.
03:34 And some motorcycles have stories about how changing a lubricant made a huge difference.
03:42 And what we were just talking about off-camera.
03:45 My experience in 1971 with Kawasaki's 500cc H1R Road Racer.
03:55 It was a triple.
03:56 It was a two-stroke.
03:57 And it wiped out first gear pinion, which is integral with the shaft.
04:04 So, you had to buy the shaft and the pinion.
04:06 And I didn't mind the work because I was going to be looking inside the engine fairly often anyway.
04:13 But it was costing us to put these shafts in.
04:17 And so, the old-timers would tell me, oh, well, you got to put ATF in them.
04:24 Oh, you've got to put 2050 motor oil in them.
04:27 Oh, you've got to put Castrol 40R in there.
04:32 So, I tried all those things.
04:34 And it just wiped out first gear pinion.
04:38 So, then I thought, what is a heavy...
04:42 Oh, I was going to say, I mean, gear oil has a much different job.
04:47 It does.
04:48 But this is oil making a difference.
04:53 So, I thought, what is a grim application for gear oil?
04:58 Helicopters.
05:00 Something's got to turn that enormous rotor at 350 RPM and with, what, 3,000 horsepower going in on some of those.
05:08 So, I called the helicopter operator out at Logan Airport.
05:11 And I said, what do you put in there?
05:13 Where do you get this mil-spec helicopter gear oil?
05:18 And there was a long silence.
05:20 And he said, you're not an FAA inspector, are you?
05:26 And I said, no, I've got this motorcycle problem.
05:29 Oh, yeah.
05:30 Okay, cool.
05:31 He said, we just go up the street to the SO station and get high point 90.
05:36 Works great.
05:37 So, I put that stuff in my H1R gearbox and it never had another failure.
05:42 It was wonderful.
05:43 Instead of scoring and pitting, it polished.
05:48 So, what I had done was to use a real gear oil in a gearbox.
05:53 And I think that we can have similar experiences with engine oil, most likely only if we're working the thing really hard.
06:04 For example, racing.
06:06 And I think that in most cases, any oil that's recommended by the owner's book is going to work.
06:15 But if you must have that feeling of becoming an active participant in your motorcycle's life, then there's a variety of synthetics that you can choose.
06:31 For example, Mobil 1 is what's called a poly-alpha olefin.
06:49 And it originated with the big diesel generator engines on the line of radar stations.
06:50 And the thing about this oil was that it had a low pour point so that the oil pump could pump it even at 40 below zero.
07:01 And then Mobil found that some European automobile applications could be satisfied by poly-alpha olefins.
07:11 And eventually, the marketing came back to the United States.
07:14 It's been very popular here.
07:16 And Motul manufactured diesters, which are another variety of synthetics.
07:28 There are so many.
07:30 And it has wonderful surface properties.
07:36 But the molecules have a long carbon chain, and then on one end of the chain is an active group, a functional group, which bonds to metal.
07:49 And in fact, if you look at Mobil 1, it has some esters in it, along with the poly-alpha olefins or PAOs.
08:00 And you could go down the list.
08:03 We used to put polyglycols in our two-strokes years ago.
08:08 And there were neopentyl polyol esters.
08:12 There were all kinds of wonderful things.
08:15 And naturally, they all claim to be the millennium in lubrication.
08:21 But what can bring us back down to earth is the owner's book.
08:26 If you follow the owner's book, you know you're not hurting your motorbike.
08:33 And if you like the smell of some oil or other, you like the look of the can, you have chosen to believe their advertising and to reject the others, that's fine.
08:50 That's a matter of taste.
08:52 But when it comes to lubricating, ultimately, the owner's book is the Bible.
08:59 But when hard times strike, for example, the German Luftwaffe in World War II, 50% of the oil they put into aircraft engines was synthesized, because they didn't have the petroleum to make mineral oil that would do the job.
09:18 So, you know, the IG Farben and company, they got on the case.
09:24 Well, let's talk about synthetic oil.
09:30 It's synthesized. We're making it.
09:33 We're picking molecules and picking arrangements to get certain qualities.
09:40 But, you know, we were initially pumping it out of the ground.
09:43 So maybe help me understand, because I have a…
09:46 Oh, sure.
09:47 I've got the dated reference romper room understanding of, yeah, we make synthetics and we can make the recipe, have the round molecules or the long molecules and do all the things because we're making it in a big high pressure temperature, many, you know, highly chemical process.
10:07 Or we're pumping it out of the ground and then we're messing with it because you can't, you're not changing it completely.
10:13 So let's talk about the difference between ground oil, dino oil, and we made it oil.
10:19 When crude oil comes up out of the well, the first type of processing that was applied to it was distillation.
10:31 They would have a big pot of crude oil at the bottom and the tower sticking up out of it and at various levels in the tower would be trays in which oil vapor could condense.
10:45 And the tray at the top of the tower collected the most volatile fractions and on downward, you got first to kerosene and then farther down, you got light lubricating oil, heavy lubricating oil, and eventually at the bottom, heavy residual oil, which is a solid at room temperature.
11:11 So the problem with this distillation process was that anything of appropriate molecular weight that boiled within a certain temperature range would collect in whatever tray of the distillation tower.
11:29 And it contained wax.
11:31 So you may have seen old motorcycles or old cars.
11:35 This is quite old.
11:36 It had little pet cocks on the cylinders.
11:40 The engine was frozen into immobility by the wax in the oil, so you had to put a little gasoline in through each one of those pet cocks and wait a few minutes.
11:50 And then you could rock the motor back and forth with the crank and finally you could rotate it and then you could start it.
11:56 So they developed various processes for getting rid of the wax and they didn't like.
12:02 Another problem was that hydrocarbons coming out of the ground have three basic structures.
12:10 One of them is straight chains of carbon atoms.
12:13 Each carbon atom has a hydrogen on either side of it.
12:17 Branch chains that might have several branches sticking out of them that had – well, some of these molecules look like combs.
12:28 And then the third structural category was aromatics, ring compounds like benzene or toluene or xylene.
12:40 I'm a big fan of toluene.
12:43 Yeah, well, toluene has its uses.
12:46 I know it sounds like a joke, but it's a great solvent and it's, I think, got some anti-knock compounds.
12:54 It's nice for knock resistance.
12:57 And you can make trinitrotoluene out of it called TNT.
13:03 [Laughter]
13:05 So it turns out –
13:07 I don't need to be able to load up my engines.
13:09 These ring compounds had vulnerable double carbon bonds in them, which made them susceptible to temperature degradation.
13:19 And, of course, what happens when your oil degrades from high temperature is you form gum.
13:26 And it used to be that piston ring sticking was just a horrible thing.
13:30 And engines had to be taken apart for a decoke every so many miles.
13:37 Well, the oil chemists, of course, said, "Well, maybe we can get rid of these aromatics."
13:44 And they found a solvent process.
13:46 And they got rid of the wax by making it stick to some other compound and then filtering it out.
13:55 And today, they don't mess with trying to take things out of the oil until what's left is good.
14:03 What they do today is they break those aromatic rings open to form straight chains.
14:12 And then they isomerize them by attaching little side chains to them to make them perform more like polyalpha olefins.
14:22 They have a low pour point, and they have a good viscosity index.
14:27 Now, here's the thing about viscosity index.
14:31 We've all heard about Pennsylvania grade, particularly the old gentleman who went to the gas station every Saturday to air up their tires.
14:41 Nobody told them that tires don't go down anymore because they have butyl rubber liners in them.
14:47 Come on, check your tire pressures, everybody. You've got to check your tire pressures and lube your damn chain.
14:54 Those Dunlop boys told me that 40% of the bikes at motorcycle rallies where they tested tire pressure were underinflated.
15:05 But this thing about viscosity index is they found that some oils made from crude from different regions of the earth,
15:18 and Pennsylvania was an important one at one time, behave better in engines because they could both lubricate the piston ring top groove,
15:30 which is hot, and the exhaust valve stem, which is hot, and the crankshaft bearings, which are comparatively cool.
15:41 I really appreciate this insight because I think a lot of us out there in, you know, ignorance land or just like thinking about it,
15:52 but not thinking about it is like, oh, yeah, I want to use 10-50 or 15-50 in my air-cooled Ducati because I really need it to,
16:03 I need that 15 because I need it to cold start and I want it to lubricate right away, which it does.
16:08 It has the pumping and everything, but it's about relative temperature in the engine.
16:13 And that was a mind-blowing concept for me, but it's absolutely true.
16:18 The bottom of the crankshaft bearings, as you say, so carry on.
16:22 They're relatively cool.
16:24 It's an important insight.
16:26 They found that these oils were more resistant to sludging and all these things.
16:31 Well, when they looked into it, they found out that, of course, what we all know, oils get thinner the hotter they are.
16:38 And if you keep pushing an air-cooled engine really hard on a hot, hot day, you may cause the oil to boil off of the cylinder wall
16:48 and you'll get piston ring scoring and failure.
16:52 Oh, bad. Don't want.
16:54 Well, that's another thing about evaporation of oil.
16:58 And that was something that I learned about in sort of kind of the Norton Commando space was a guy was testing all these different oils,
17:07 a very thorough engineer type.
17:10 And he talked about like, I don't like the evaporative qualities of oil X, and it was part of the oil consumption.
17:17 Well, this is very much the case.
17:20 The problem with that is that when they made multigrade oils starting about 1950, which I'll cover in a minute,
17:32 what a multigrade oil is, is a base stock which is thin enough for your engine to cold start
17:40 with its viscosity boosted in a temperature sensitive way by putting these really long noodles into the oil.
17:50 They have molecular weights between 50,000 and 500,000.
17:56 Let me write that down, really long noodles.
17:59 Yes. Well, the thing about those noodles is that when it's cold, the noodles do what we do when it's cold.
18:08 They kind of hug themselves and they roll up into a more compact structure, which does not affect viscosity very much.
18:18 But as they warm up, they are more inclined to spread their little wings.
18:25 And then they do make a very large contribution to viscosity.
18:30 But the viscosity index of any base stock oil is the rate at which it loses viscosity as temperature rises.
18:41 This produces a slope. And that slope is called viscosity index or VI.
18:49 You'll often see it in the literature as just VI.
18:53 Now, what we want is a good relationship is one that has the same viscosity at all temperatures.
19:02 And there is no engine oil made that can actually achieve that.
19:07 So what we're after is a higher rather than a lower viscosity index.
19:12 In the old days of distilled oils, the viscosity index was lousy, except for Pennsylvania grade.
19:22 And in its case, it was the oil molecules in what they used to call Pennsylvania grade had some of this noodle characteristic,
19:31 namely the molecules were more compact at low temperature so that they didn't become so viscous.
19:39 And as the temperature rose, they unfolded like a flower and the viscosity loss was offset to a degree.
19:50 There is no viscosity improver that will make your oil have constant viscosity.
19:57 So this process seemed too good to be true.
20:04 So the diesel people who have really hot top piston ring grooves were very suspicious of it.
20:11 We're not going to we're not going to go with that.
20:15 But after 1950, they began to instead of a 30 weight oil, which is what we all put in lawnmowers,
20:23 they would make something like a 20 40 20 W 40.
20:29 And what that those two numbers mean is that at zero degrees, it behaves like a 20 oil.
20:38 And at boiling water temperature, it behaves like a 40 oil.
20:45 And. These viscosity characteristics are are not physical measurements, that is, you can't measure it at home,
20:57 you'd have to get a viscometer and learn the conversion.
21:01 You know, there's charts and all this wonderful stuff.
21:04 Well, surely I could just pour some on a piece of cardboard and turn it sideways and see what happens.
21:09 You could do that. Yes. And often those experiments are the most valuable because they're they're direct and you can look at what you're doing.
21:18 It's not something coming out of a book. Oh, I see. Sort of.
21:22 Well, it's hard to argue with minus 27 in Minnesota when you're starting your rental car.
21:27 You got it. Oh, my God.
21:30 That's the California guy. Boy, that's terrible, terrible sounds.
21:34 Anyways, I remember that there was a popular 2050, 50 years ago, and somebody who was a lot more knowledgeable about oils than I was said,
21:45 you will find that your oil consumption is quite heavy with that material because.
21:53 A multigrade oil consists of a base stock, which is the thin stuff that will allow your engines cold start mixed with these noodles,
22:03 which are these variable geometry molecules that unroll to become very long.
22:10 And. The base stock in this oil was not hydro finished and.
22:19 I so de-waxed and all these other wonderful things, it was just pretty much straight run stuff and had had a bunch of aromatics in it.
22:28 So. A lot of that oil would evaporate off the cylinder wall and mix.
22:35 With combustion gas. Some of it would be swept down into the crankcase.
22:40 Some of it would go out the exhaust. So naturally, the automakers having to meet increasingly stringent emissions laws since about 1970.
22:54 Saw this. Oh, look. Base stock is parts of the base stock are evaporating off the cylinder wall and becoming unburned hydrocarbons.
23:05 Make a better base stock. So that's what the refinery companies did.
23:10 They found ways to make mineral based stocks that were more uniform.
23:16 People have said that a synthetic oil is like an army of identical, robust.
23:24 Powerful, agile young men, they're all six feet tall.
23:28 They can all do 100 pushups and so forth because they are not they don't represent a distribution of molecular types.
23:37 Whereas a real army consists of a fat guy, a thin guy, a regular guy, a tall guy, short guy.
23:43 And turns out those short guys evaporated off the cylinder walls.
23:48 So those guys had to be marginalized. Push those guys away.
23:54 Yep. Relentlessly. And so the oil companies got busy with their whole armamentarium of catalysts and high temperature, this and cold process that.
24:07 And they got rid of them so that now the base stock that goes into good quality mineral oil, and that would be American Petroleum Institute Group 3.
24:22 API people, if you ever see that, that's we'll get to that in a minute.
24:26 But API is extremely important, particularly with the motorcycle and clutches.
24:32 And then there's questions about tappets and all other things. But API, we'll talk about that in a minute. But go ahead.
24:38 Yeah. So these advanced, they're not refining processes. Refining is taking out the defective parts and what's left behind is good.
24:53 The new method of making mineral oils actually reforms the molecules. It breaks those nasty aromatic rings open and then it attaches little extra side chains onto them and makes ideal lubricants out of them.
25:13 Because synthetics are made out of carbon and hydrogen. They are not something uniquely special.
25:21 They're just an arrangement of their, they are a high performance arrangement or an optimized arrangement of the hydrogens and carbons.
25:32 And mineral oils are converging with that to such an extent that the Better Business Bureau a few years back finally announced that they would allow this Group 3 called synthesized hydrocarbons to be so-called, to be characterized as synthetic.
25:56 So they're both attempting to achieve the same thing, this army of identical six foot tall, robust soldiers.
26:06 So I have a question. Yep. Go ahead.
26:08 Go ahead.
26:09 My question is base stock. So you keep talking about base stock and I would assume that that's the bulk of the recipe. And I've always thought, well, you know, there's the actual oil and then there's all the other stuff they put in it to do different things.
26:27 So I'm kind of curious about like, what's the base stock percentage and then what are the other components at play and how much actual oil do we want in there? It's the question, I guess.
26:40 Well, this is something that old timers who were then younger than I am now would say. They'd say, give me an oil that's 100% oil. I don't want none of them additives.
26:57 All right. Here is a, an example of a spark ignition mineral motor oil. It is 77.6% base stock. So it's two or three quarters of it. A little more than three quarters of it is the base stock.
27:15 Oil.
27:16 Then 10.9% is noodles. The viscosity index improver.
27:25 Getting our 2050 out of something. So we got it.
27:28 You bet.
27:29 Yep.
27:30 And then six and a half percent is ashless, which means not containing metal in this case. Ashless dispersant. And you can think of a dispersant as opposed to a detergent as being a sort of molecular trash man with hefty trash bags, who's able to stuff them with unwanted things like
27:57 soot particles, either from a diesel engine or from a direct injection automobile engine, direct cylinder, what do they call it? GDI.
28:08 And these people, they love that stuff. And then 2.5% metal based detergent and a detergent like a soap forms a monolayer all over the surface of anything that it finds.
28:27 And that monolayer prevents it from sticking to other particles. So it's very good protection against sludging. Because sludging, oh, here are some other sludge particles. Let's form a club.
28:44 Let's build a house. And they build that house. It's marvelous to see an engine that has been run on nothing but pure oil. And I did this when aviation author Graham White and I started to take the accessory drive case off the back of a 28 cylinder Pratt & Whitney aircraft engine.
29:10 We finally took off all the fasteners. And then we kind of eased back on this. It's a big magnesium plate.
29:19 Just pointing out that you had a 4360, the engine you're talking about hanging from a gantry crane in your shop.
29:26 I did have. It's a weakness. But I've overcome it. I went to a help group. And I've been able to come back on that.
29:40 Come back on your 4360s and your gantry cranes.
29:42 Yes, sir. Now let's go through this list. 1.4% inhibitor, which is basically anti-corrosion stuff. And then 1.1% anti-wear, which is a stuff that protects metal surfaces when the parts are not moving rapidly enough to develop a full oil film to separate them.
30:10 The anti-wear forms a solid lubricant layer wherever there is a very high temperature, for instance, from local friction.
30:20 And that layer is shearable. The friction in that layer is from 1 to 10% of the friction of dry metal on metal.
30:34 So it's a very useful reduction and it prevents the scoring and scratching that you would have otherwise.
30:42 But anyway, back to this point.
30:44 ZDDP. We should...
30:46 Yes, ZDDP. Let us all join in unison to say zinc di-alkyl di-thio-phosphate.
30:52 Sounds like the chorus to a great song.
30:56 Yes, that's right. Tom Lehrer should... Where are you? So we pulled that cover off the back of the engine and it was solid sludge. It looked like gravy.
31:14 And just as Graham put his hand into it, I was calling out, "Sharp things!" And he cut himself.
31:24 Because stuck in that sludge were all the little curlicues of metal that this engine had generated over... I think when that one came apart, it looked like it probably had the best part of a thousand hours.
31:38 But all this horrible sludge. And I took apart a '40 Chevy engine and it was black. Just horrible sludge.
31:48 Yeah, I'd have paid a '58 Triumph that was horrific. The bottom of the oil tank was sludge that was this thick.
31:54 Now I want to pause because you called it gravy. And gravy is another important lubricant that we...
32:00 Don't disparage gravy. Gravy's great. And in the past, Kevin, we had a long email chain going many years ago. It was called the Excellence of Butter.
32:10 So we could talk about some other... the way lubricants work and...
32:16 Well, for example, the use of mayonnaise as a swallowing agent.
32:21 A mouthful of dried chicken, you swallow that thing and it can just decide, "I'm staying here!"
32:29 Yep. Viscosity index, very important.
32:32 Yes, sir.
32:33 So, you were saying...
32:36 About the sludge.
32:37 Well, the thing about sludge is, eventually, hard balls of sludge detach from the clubhouse and plug things up.
32:47 They can plug up little oil ways and so forth.
32:51 But I did some videos with a CBR 600RR engine, Honda, that had 26,000 miles on it.
33:04 I took that thing apart and I was going to bow down and worship, as you mentioned at the outset here, because it was beautiful inside.
33:14 No sludge. All the oil holes that I could see were nice and open.
33:21 And I'm sure that if I had applied oil pressure to where the pump sits, that oil would have spouted out of all of these little holes, as it must, in order for the thing to last like that.
33:38 The engine was beautiful inside.
33:40 And, of course, what happens is that things like the detergent and the dispersant round up all the bad guys and herd them off to the filter where they are stopped.
33:52 And the really little stuff, of course, you see that the oil turns black with time if you don't constantly change it.
34:00 Some of those wear particles and sludgy stuff is in the oil and goes out with the oil change.
34:09 But so the answer is here we've got roughly 22% additives in this spark ignition motor oil.
34:22 And I think that's a fair estimate for any of the oils that we would put into a motorcycle engine.
34:30 And it's very much worthwhile having an anti-corrosion that prevents what happens.
34:37 Anybody who has ever taken apart an old two-stroke, that is one that's not been ridden for two years, knows that the crank is likely rusted.
34:47 And so having that anti-corrosion stuff in there means that your camshafts are going to be as bright and shiny as the ones in that 26,000-mile engine that I took apart.
34:59 And there are long lists of these additives.
35:04 And there are wonderful mouth-filling chemical names for all of the ingredients.
35:09 And I have not learned that stuff, but the people who spend their lives in this field are just...
35:17 You try to read those textbooks and you feel like an armor-piercing shell that is very slowly making its way through hard steel.
35:28 So there's a lot to know. If you want, the books are all waiting for you.
35:38 Well, one thing I want to ask, what we haven't addressed here is, how does oil work?
35:44 And you kind of implied, oh, ZDDP works, the zinc works by forming a film at high temperature.
35:52 Classic car and classic bike people want that flat tappet protection of cam rolling up on a flat tappet.
36:03 So maybe explain how oil actually works in an engine, because we don't have roller bearings everywhere anymore.
36:11 Everything's a plain bearing, mostly. And how does that work?
36:15 Medium rain is coming down, and Richard Schlachter and I are driving up the backside of...
36:22 It's the front side to you people. But we're driving up the backside of the Rocky Mountains.
36:27 And I get to 58 miles an hour on this long climb, and I notice that the engine is tacking up.
36:36 Oh, we're hydroplaning. Well, what's happening in hydroplaning is that the tire is pushing water ahead of it...
36:46 Until the thickness of that film of water in front of the tire becomes great enough to support the weight of the vehicle on that tire.
36:57 And this is exactly what happens when you start your engine and all the moving parts, such as the piston sliding in their bores...
37:07 The crankshaft journals turning in their bearings, and the cam lobes and tappets trying to grind one another down...
37:16 Is that they hydroplane on a lovely film of oil, and the bearings, all of these encounter groups...
37:26 Are designed so that... To favor the formation of this wedge-shaped oil film.
37:35 So, if we're looking at a journal bearing, the outside of the bearing, the bearing shells are nice and round...
37:46 And in the midst is the round journal of the crankshaft. The load pushes the journal slightly off-center in the bearing, allowing an oil wedge to form.
38:00 And the rotation of the journal drags the oil... Because it has viscosity, it can drag the oil from the low-pressure zone...
38:13 Which is constantly being filled up with fresh oil by the oil pump, into the loaded zone, where it does its good work.
38:22 And in that loaded zone, the closest approach of the journal to the bearing can be a couple of microns.
38:30 A micron is a millionth of a meter. So, it's wicked thin.
38:36 Wicked thin, but they, in a perfect world, they never touch.
38:40 They never touch. And there have been... Yeah. There have been cases in which the vertical thrust bearing on a hydraulic turbine, in a small rural dam, generating a little bit of electricity for the local folks...
38:57 That has sat there for 30 years and never stopped once, was supported so perfectly on the oil film...
39:07 That when the thing was finally taken down and either sent to Ecuador or scrapped, the original hand-scraping marks on those tilting pad thrust pieces were still there.
39:22 In other words, no wear at all.
39:25 Amazing. Well, that's what we're going for, right? That's why we want to pick exactly the right oil and put it into our bikes.
39:33 Because we want it to have no wear. We want it to be as beautiful at 30,000 miles as it was when it was 1,000.
39:39 We do. And the thing is that the only thing that is supporting the load when you have complete film, hydrodynamic lubrication they call it, is the viscosity of the oil.
39:53 It doesn't respect the name of the oil's manufacturer, the name of the molecular species.
40:01 All that counts is viscosity, namely that the motion of the parts can sweep oil into the loaded zone fast enough to separate the moving parts from each other.
40:15 Just as when I got to 58 miles per hour, the tire climbed up on the water film and the engine tacked up.
40:24 Yes. And the steering became...
40:27 It was wonderful.
40:28 What?
40:29 When I slowed down to 55 miles per hour, it was perfect. No problem.
40:34 So what has happened? What has changed that we've gone from 2050, like my Velocette would want 2050?
40:45 Yes, it would.
40:46 But our Toyota 4Runner wants 020. Now, what is going on?
40:52 Yes. Well, what's going on is that years and years ago, Junior Johnson became greatly impressed by the amount of horsepower that was lost by the crankshaft transferring kinetic energy to oil.
41:09 And he wanted to reduce the amount of oil that was flying around in the crankcase.
41:14 So he went to the specialist guys and they said, "Well, you could tighten up the bearing clearances, but then there wouldn't be enough oil coming through to cool the bearing.
41:29 And so you're sort of stuck there."
41:32 So then he asked the next echelon of people, older people who had other experiences.
41:38 And he found out that during World War II, the manufacturers of large aircraft engines wanted to reduce the amount of valuable aircraft gasoline used in break-in.
41:56 So they said, "Let's produce an extremely fine surface finish on the journals of the crankshaft."
42:05 And they developed a method of doing this, which was saddle-shaped abrasive stones, which were supported on a lubricating film.
42:17 And they would let the temperature go up and up and the lubricant would become warmer and it would lose viscosity and the stones would come closer to the surface.
42:26 And at a point, they would start to lop off just the asperities, they loved to call them.
42:32 The little mountains on the surface were being ground down.
42:37 And as they let the stones come closer and closer, they could end up with a surface that was not only extremely shiny, like a crankshaft that has been micro-finished, which is the same as polishing your shoes, but it would be truly cylindrical.
42:53 Well, I think the first motorcycle engine that I was aware of that had super-finished, this was a wartime process, super-finished crank pins and main journals was Goldwing.
43:09 And they could put much thinner oil in there because the thing you don't want to happen is that the rotating journal gets so close to the bearing surface, the oil film becomes so thin that the asperities stick up and hit the journal.
43:28 I do love the word asperity. I love the word asperity.
43:31 Yes.
43:32 Asperations, right, we're pointing up. And that's the thing is it's making the surface so beautiful and so perfectly round that you're getting rid of that area where it could poke through the film. It's so, so fine.
43:46 So you can make the film, the film can now safely be thinner, which means that you can use a lower viscosity oil, which reduces friction by a measurable amount. You're not going to be able to contribute the money you save from this to your child's college fund.
44:04 It's not a significant amount, but it can be enough to get them through all those tricky federal regulations. So that has driven the move from the old days, which was 20, 30, 40, we're in those places, to the 015 business.
44:26 Now, I remember talking to Rob Muzzy about this. He said, "Oh, these oil people are in here and they got us trying all this stuff. 015, what does it even mean?"
44:38 But his further conversation revealed that he'd learned a lot from those guys.
44:45 And what has happened now is that new car and new motorcycle crankshafts are finished to a higher standard, both of irregularity, that is, asperity height. In the Himalayas, the asperity height is very large.
45:04 And out at sea, it's moderate. And in the desert, it can be.
45:11 So this has allowed us to use lower viscosity oils.
45:19 And at some reduction in fuel burn.
45:25 And if you apply this to a whole nation, presumably the people up there in Ann Arbor just rub their hands together in glee at the thought of the tons and tons of CO2 they were saving us from.
45:38 So good for them.
45:40 So I would like to finish with API, if we can do that effectively.
45:45 And then what you said earlier about following the manual for your motorcycle, the recommended oil.
45:52 So tell us about, I mean, API is something that you should do the Google research on, right?
46:00 Yeah.
46:01 Massive Petroleum Institute. Yeah.
46:03 And then, and understand those and look at the number that's recommended for motorcycles versus that which is used in automobiles and the different job that oil in a motorcycle can have, including lubricating the gearbox and being in the clutch.
46:18 What the motorcycle manufacturer, motorcycle oil manufacturers will tell you is our oil has offers more protection because motorcycle camshafts have a more, a grimmer relationship with the, between the lobe and the tap.
46:36 And I'm sure that, that when they used to advertise after the Indianapolis 500 X, Y, Z oil road with the winner, I thought, yeah, and a little two ounce can under his seat.
46:50 It reminds me of being in the pit at Laguna Seca, you know, 15 years ago to super bike race and very large American motorcycle racing team had oil, you know, oil bottles and chemical bottles all over their paddock.
47:07 And it's, it was all taped off and somebody had written on it with a Sharpie, very fast oil, your name here.
47:15 They were looking for an oil sponsor.
47:17 Very good.
47:18 It was awesome.
47:19 Anyway, carry on.
47:20 Well, I learned that, that anyone who wants to be an oil manufacturer can become one.
47:26 Because what you do is you are your base stock from that supplier.
47:31 And if you have to supplement the base stock with a, with a polar molecule, like an ester, you order in some from those guys.
47:40 And then you, you phone up the manufacturers of additive packages.
47:47 Now, it often turns out that the additive package that is designed to be soluble in mineral oil is less soluble in certain synthetic.
47:56 So, there are rules that must be abided by, but there's nothing to stop somebody from, from just becoming a manufacturer of oil.
48:05 And they mix all, you know, it's like it's in the old song.
48:09 I'm going to mix it up right here in the sink.
48:11 And they put it in cans or bottles.
48:14 And we buy it.
48:17 So, and the API is there to backstop things with, by setting standards.
48:23 And you'll see on the oil container, the starburst that shows four-stroke engines.
48:31 And then the oil service category, which last time I looked was SN.
48:39 It's probably some, it's moved on by like those frogs you see crossing the road at night.
48:44 It hops forward.
48:46 And, oh, what's this?
48:49 But you can look that up online by looking for the API oil service categories.
48:57 And it'll explain it all to you.
48:59 And you will be your own expert.
49:02 I think that's a, that's a great spot.
49:05 You should be your own expert and, you know, apply practical thinking, become your own expert, light the dark places.
49:14 And as I think you said in sport bike performance handbook, someone asked you, or you were always posed with the question, like, how often should I change my oil?
49:23 And you said, well, there's probably some benefit to changing your oil every 10 minutes, but.
49:30 Yeah.
49:31 But.
49:33 Actually, what goes on is that the oil has a finite amount of additives in it.
49:39 And the, what controls the, what switches on the change oil now in your car, if your car has this feature, is an algorithm and not something that's being measured in the oil.
49:54 The algorithm says, how long has this engine spent at various conditions of operation?
50:01 Well, let me see now.
50:03 And then it says, change oil now.
50:06 And what that is based on is the likely consumption of ZDDP or other anti-wear additives.
50:14 In other words, when your oil is worn out, you should change it.
50:18 If you want to change it more often than that, if you want to flatter yourself while I ride real hard, go ahead.
50:25 That's fine with me.
50:26 And it's fine with the oil.
50:29 The other thing that can happen is if the oil, if used too long or operated too hot, can fall out of grade.
50:37 The noodles break.
50:40 When the noodles break, you don't get the viscosity heightening effect of those long molecules that are swimming around in amongst the base stock, like eels.
50:55 And half an eel just doesn't cut it.
50:59 So this is something that trucking companies do.
51:02 They send drain oil and they get a report back that says, oh, well, this oil is performing well.
51:08 Your viscosity is held up and so forth.
51:11 Or they say, this oil has fallen out of grade.
51:14 Look for all these failures in your engine.
51:16 And that is one thing I wanted to say before we finish, is get your oil checked.
51:23 Use an immaculately clean drain pan and put the oil in there.
51:28 And there are services.
51:29 It's not that expensive.
51:31 They can tell you exactly what's going on.
51:33 You want to drain it out at 3,000?
51:34 Like, oh, I think 3,000 is the way to go.
51:36 Drain it out at 3,000 and send it off and see what they say about it.
51:40 See what's in it and how it's performing.
51:42 It's not that expensive.
51:43 And then you could wait until 5,000 and do it again and see if there's a difference.
51:47 And to me, that is absolutely fascinating.
51:52 But I also have a book on my desk here that says, you know, oscilloscopes, selecting and restoring a classic.
51:59 Not everybody wants to send their oil out.
52:02 And you could just change it at 3,000.
52:04 But use the recommended oil, the recommended weight, and the right API grade, SJS, whatever.
52:10 Look that up and feel confident that your motorcycle will last as long as you need it to.
52:17 And it will look like that CBR you took apart with 20-whatever-thousand miles of water.
52:21 It was so beautiful.
52:23 I love that thing.
52:24 Yep. All right.
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