What OIL do I use in my MOTORCYCLE?
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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SportsTranscript
00:00 Welcome to the Cycleworld podcast. I'm Mark Hoyer, Editor-in-Chief, and I'm with
00:03 Kevin Cameron, Technical Editor. We're back. We tend to talk about religious
00:09 subjects occasionally. Motorcycles are a religion. This is even, this topic is even
00:14 more religious than religion. This is "What oil do I put in my bike? What oil do
00:19 I use for the whatever?" It has been, I would say, the number one question, even
00:26 in the back, back in the days of snail mail and getting letters mailed to the
00:29 office. It was, "What oil do I use?" And it is, you know, we want the elixir that
00:36 causes, or that saves us from anywhere at all, that makes our motorcycle last
00:41 forever, make the most power, and just be as perfect as can be. What do I do, Kevin?
00:48 What do I do? As we know, motorcyclists want to refresh that new bike feeling
00:57 regularly. So these people who are talking about wanting to make their
01:03 motorcycle last 30 years, do not persuade me that they are sincere. Because I know
01:11 that in two years they're going to buy some new whiz-bang, wonderful model that
01:17 has features we can't even dream of today, and the other one will go off to a
01:23 new owner. So making a motorcycle last forever, I understand the sentiment. But
01:31 basically what we have to do is first choose oils that fall within the
01:39 recommendation of the manufacturer presented in the owner's book. Because
01:44 each manufacturer, when a new model is produced, goes through an extensive
01:50 process of oil proving in which they work out exactly what spec is going to
01:57 give the best results with their product. Now, is it likely that my buddy at the
02:04 cycle shop is going to be able to give me a tip that improves greatly on what
02:09 the manufacturer has discovered? I don't think so. But on the other hand, there's
02:14 another consideration, and that is, I've just paid 30 grand for some lovely piece
02:21 of equipment, and I worship it. I remove every flak of dust, and I behold it. I put
02:29 on strong light to make it even more powerful an experience. But what I want
02:36 to do with oil is I want to do something for my motorcycle. And I can sympathize
02:42 with that. We know that there are homeowners who put in plantings lovingly
02:48 and expensively because they want to do something for what they have there. And
02:54 so it used to be that the obvious answer was, "Well, you'll have to put synthetic
03:02 oil in because that will enable you to pay $30 a quart." Well, I can vote, you
03:07 know, I can vouch for some synthetic oil options, particularly on the automotive
03:11 side. Vintage Jaguars with the four-synchro gearbox love a synthetic
03:19 gearbox oil in either the 30-weight or 40-weight equivalent, so an MT90 or what
03:24 they would call MTL, like manual transmission light. Synchros, everything
03:29 works better. So there is something there. Oh, definitely. And some
03:36 motorcycles have stories about how changing a lubricant made a huge
03:42 difference and what we were just talking about off-camera. My experience in 1971
03:49 with Kawasaki's 500cc H1R Road Racer. It was a triple, it was a two-stroke. And it
04:00 wiped out first gear pinion, which is integral with the shaft, so you had to
04:05 buy the shaft and the pinion. And I didn't mind the work because I was going
04:10 to be looking inside the engine fairly often anyway, but it was costing us to
04:16 put these shafts in. And so the old-timers would tell me, "Oh, well, you've got to put
04:23 ATF in them. Oh, you've got to put 2050 motor oil in them. Oh, you've got to put
04:29 Castrol 40R in there." So I tried all those things and it just wiped out first
04:36 gear pinion. So then I thought, "What is a heavy..." Oh, I was gonna say, I mean,
04:43 gear oil has a much different job. It does, but this is oil making a
04:50 difference. So I thought, "What is a grim application for gear oil?
04:58 Helicopters. Something's got to turn that enormous rotor at 350 rpm and with, what,
05:04 3,000 horsepower going in on some of those." So I called the helicopter
05:09 operator out at Logan Airport and I said, "What do you put in there? Where do you
05:13 get this mil-spec helicopter gear oil?" And there was a long silence and he said,
05:20 "You're not an FAA inspector, are you?" And I said, "No, I've got this
05:28 motorcycle problem." "Oh, yeah. Okay, cool." He said, "We just go up the street to the
05:33 SO station and get high point 90. Works great." So I put that stuff in my H1R
05:40 gearbox and it never had another failure. It was wonderful. Instead of scoring and
05:44 pitting, it polished. So what I had done was to use a real gear oil in a gearbox.
05:52 And I think that we can have similar experiences with engine oil, most
06:01 likely only if we're working the thing really hard. For example, racing. And I
06:07 think that in most cases, any oil that's recommended by the owner's book is going
06:14 to work. But if you must have that feeling of becoming an active participant
06:23 in your motorcycle's life, then there's a variety of synthetics that you
06:30 can choose. And for example, Mobil 1 is what's called a poly-alpha olefin. And it
06:40 originated with the big diesel generator engines on the Dooline, that
06:46 line of radar stations. And the thing about this oil was that it had a
06:54 low pour point so that the oil pump could pump it even at 40 below zero. And
07:01 then Mobil found that some European automobile applications could be
07:09 satisfied by poly-alpha olefins. And eventually the marketing came back to
07:13 the United States. It's been very popular here. And Motul manufacture
07:19 diesters, which are another variety of synthetics. There are so many. And it
07:31 has wonderful surface properties. The molecules have a long carbon chain. And
07:41 then on one end of the chain is an active group, a functional group, which
07:47 bonds to metal. And in fact, if you look at Mobil 1, it has some esters in it,
07:55 along with the poly-alpha olefins or PAOs. And you could go down the list. We
08:03 used to put polyglycols in our two-strokes years ago. And there were
08:10 neopentyl polyol esters. There were all kinds of wonderful things. And
08:16 naturally, they all claim to be the millennium in lubrication. But what can
08:22 bring us back down to earth is the owner's book. If you follow the owner's
08:28 book, you know you're not hurting your motorbike. And if you like the smell of
08:38 some oil or other, you like the look of the can, you have chosen to believe
08:45 their advertising and to reject the others, that's fine. That's a matter of
08:51 taste. But when it comes to lubricating, ultimately the owner's book is the
08:58 Bible. But when hard times strike, for example, the German Luftwaffe in World
09:06 War II, 50% of the oil they put into aircraft engines was synthesized, because
09:13 they didn't have the petroleum to make mineral oil that would do the job. So,
09:20 you know, the IG Farben and company, they got on the case.
09:24 Well, let's talk about synthetic oil being synthesized. We're
09:32 making it. We're picking molecules and picking arrangements to get certain
09:39 qualities. But, you know, we were initially pumping it out of the ground.
09:42 So maybe help me understand, because I've got the dated
09:49 reference romper room understanding of, yeah, we make synthetics and we can
09:53 make the recipe, have the round molecules or the long molecules and do all the
09:58 things, because we're making it in a big high-pressure temperature, many, you
10:05 know, highly chemical process. Or we're pumping it out of the ground and then
10:09 we're messing with it, because you're not changing it completely. So
10:13 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
10:28 applied to it was distillation. They would have a big pot of crude oil at the
10:34 bottom and the tower sticking up out of it. And at various levels in the tower
10:39 would be trays in which oil vapor could condense. And the tray at the top of the
10:47 tower collected the most volatile fractions. And on downward you got first
10:57 to kerosene and then farther down you got light lubricating oil, heavy
11:02 lubricating oil, and eventually at the bottom heavy residual oil, which is a
11:09 solid at room temperature. So the problem with this distillation process was that
11:17 anything of appropriate molecular weight that boiled within a
11:23 certain temperature range would collect in whatever tray of the distillation
11:28 tower. And it contained wax. So you may have seen old motorcycles or old cars,
11:34 this is quite old, that had little petcocks on the cylinders. The engine was
11:41 frozen into immobility by the wax in the oil, so you had to put a little gasoline
11:47 in through each one of those petcocks and wait a few minutes. And then you could
11:50 rock the motor back and forth with the crank and finally you could rotate it
11:54 and then you could start it. So they developed various processes for getting
11:59 rid of the wax. And they didn't like... Another problem was that hydrocarbons
12:06 coming out of the ground have three basic structures. One of them is straight
12:11 chains of carbon atoms. 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
12:23 had... Some of these molecules look like combs. And then the third
12:30 structural category was aromatics ring compounds like benzene or toluene or
12:38 xylene. I'm a big fan of toluene. Yeah, well toluene has its uses. I know it
12:47 sounds like a joke, but it's really a great solvent and it's I think got
12:53 some anti-knock compounds. It's nice for knock resistance. And you can make
12:58 trinitrotoluene out of it called TNT. So I don't need to load up my engines.
13:08 These ring compounds had vulnerable double carbon bonds in them which made
13:14 them susceptible to temperature degradation. And of course what happens
13:21 when your oil degrades from high temperature is you form gum. And it used
13:26 to be that piston ring sticking was just a horrible thing. And engines had to be
13:32 taken apart for a decoke every so many miles. Well, the oil chemists of course
13:40 said, "Well, maybe we can get rid of these aromatics." And they found a solvent
13:45 process and they got rid of the wax by making it stick to some other compound
13:52 and then filtering it out. And today they don't mess with trying to take things
13:59 out of the oil until what's left is good. What they do today is they break those
14:07 aromatic rings open to form straight chains and then they isomerize them by
14:14 attaching little side chains to them to make them perform more like polyalpha
14:21 olefins. They have a low pour point and they have a good viscosity index. Now
14:28 here's the thing about viscosity index. We've all heard about
14:33 Pennsylvania grade, particularly the old gentleman who went to the gas station
14:38 every Saturday to air up their tires. Nobody told them that tires don't go
14:43 down anymore because they have butyl rubber liners in them. But those were the
14:49 gentlemen... Come on, check your tire pressures everybody. You've got to check your tire pressures and lube your
14:53 damn chain. Well, those Dunlop boys told me that 40% of the bikes at
15:00 motorcycle rallies where they tested tire pressure were under inflated. Yeah. But
15:08 this thing about viscosity index is they found that some oils made from crude
15:15 from different regions of the earth, and Pennsylvania was an important one at one
15:20 time, behave better in engines because they could both lubricate the piston
15:29 ring top groove, which is hot, and the exhaust valve stem, which is hot, and the
15:37 crankshaft bearings, which are comparatively cool. I really appreciate
15:42 this insight because I think a lot of us out there in, you know, ignorance land or
15:50 just like thinking about it but not thinking about it is like, "Oh yeah, I want
15:54 to use 10-50 or 15-50 in my air-cooled Ducati because I really need
16:02 it to... I need that 15 because I need it to cold start and I want it to lubricate
16:06 right away," which it does. It has the pumping and everything, but it's
16:10 about relative temperature in the engine and that was a mind-blowing
16:17 concept for me, but it's absolutely true. The bottom of the crankshaft bearings, as
16:20 you say. So carry on. But I mean... They're relatively cool. It's an important insight.
16:26 They found that these oils were more resistant to sludging and all these
16:31 things. Well, when they looked into it, they found out that, of course, what we all
16:35 know, oils get thinner the hotter they are. And if you keep pushing an
16:41 air-cooled engine really hard on a hot, hot day, you may cause the oil to boil
16:47 off of the cylinder wall and you'll get piston ring scoring and failure. Oh, bad.
16:53 Don't want... Well, that's another thing about evaporation of oil and that
16:59 was something that I learned about in sort of kind of the Norton Commando
17:03 space was a guy was testing all these different oils, a very thorough
17:08 engineer type, and he talked about like, "I don't like the evaporative qualities
17:13 of oil X," and it was part of the oil consumption. Well, this is very much
17:19 the case. Yeah. The problem with that is that when they made multi-grade oils
17:26 starting about 1950, which I'll cover in a minute, what a multi-grade oil is, is a
17:34 base stock which is thin enough for your engine to cold start with its
17:41 viscosity boosted in a temperature sensitive way by putting these really
17:47 long noodles into the oil. They have molecular weights between 50,000 and
17:54 500,000. Let me write that down, really long noodles. Yes. Well, the thing about
18:01 those noodles is that when it's cold, the noodles do what we do when it's cold.
18:07 They kind of hug themselves and they roll up into a more compact structure
18:13 which does not affect viscosity very much, but as they warm up, they're more
18:22 inclined to spread their little wings and then they do make a very large
18:28 contribution to viscosity. But the viscosity index of any base stock oil is
18:35 the rate at which it loses viscosity as temperature rises. This produces a slope
18:42 and that slope is called viscosity index or VI. You'll often see it in the
18:50 literature as just VI. Now, what we want is a good relationship is one that has
18:59 the same viscosity at all temperatures and there is no engine oil made that can
19:05 actually achieve that. So what we're after is a higher rather than a lower
19:10 viscosity index. In the old days of distilled oils, the viscosity index was
19:18 lousy except for Pennsylvania-grade. In its case, the oil molecules in what
19:27 they used to call Pennsylvania-grade had some of this noodle characteristic,
19:31 namely the molecules were more compact at low temperatures so that they didn't
19:37 become so viscous. As the temperature rose, they unfolded like a flower and
19:44 the viscosity loss was offset to a degree. There is no viscosity improver
19:53 that will make your oil have constant viscosity. So this process seemed too
20:03 good to be true. So the diesel people who have really hot top piston ring grooves
20:09 were very suspicious of it. 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
20:21 in lawnmowers, they would make something like a 20W40. And what
20:30 those two numbers mean is that at zero degrees, it behaves like a 20 oil, and at
20:39 boiling water temperature, it behaves like a 40 oil. And these viscosity
20:51 characteristics are not physical measurements. That is, you can't measure
20:56 it at home. You'd have to get a viscometer and learn the conversion.
21:01 There's charts and all this wonderful stuff.
21:03 Well, surely I could just pour some on a piece of cardboard and turn it sideways
21:07 and see what happens, can't I?
21:08 You could do that, yes. And often those experiments are the most valuable
21:14 because they're direct and you can look at what you're doing. It's not
21:18 something coming out of a book, "Oh, I see," sort of.
21:22 Well, it's hard to argue with -27 in Minnesota when you're starting your
21:25 rental car.
21:26 You got it.
21:27 Oh my God, the California guy. Boy, that's terrible, terrible sounds.
21:34 Anyways.
21:35 I remember that there was a popular 2050, 50 years ago, and somebody who was
21:41 a lot more knowledgeable about oils than I was said, "You will find that
21:47 your oil consumption is quite heavy with that material because a multi-grade
21:54 oil consists of a base stock, which is the thin stuff that will allow your
21:59 engine to cold start, mixed with these noodles, which are these variable
22:04 geometry molecules that unroll to become very long.
22:12 The base stock in this oil was not hydro-finished and ISO de-waxed and
22:21 all these other wonderful things. It was just pretty much straight run stuff.
22:26 It had a bunch of aromatics in it. A lot of that oil would evaporate off the
22:32 cylinder wall and mix with combustion gas. Some of it would be swept down
22:39 into the crankcase, some of it would go out the exhaust. Naturally, the
22:44 automakers having to meet increasingly stringent emissions laws since about
22:52 1970 saw this. Oh, look, base stock, parts of the base stock are evaporating
23:01 off the cylinder wall and becoming unburned hydrocarbons. Make a better
23:05 base stock. That's what the refinery companies did. They found ways to make
23:13 mineral-based stocks that were more uniform. People have said that a
23:17 synthetic oil is like an army of identical, robust, powerful, agile young
23:26 men. They're all six feet tall. They can all do 100 push-ups and so forth
23:32 because they don't represent a distribution of molecular types. Whereas
23:37 a real army consists of a fat guy, a thin guy, a regular guy, a tall guy, a
23:42 short guy. Turns out those short guys evaporated off the cylinder walls. Those
23:50 guys had to be marginalized. Push those guys away relentlessly. The oil
23:57 companies got busy with their whole armamentarium of catalysts and high
24:03 temperature this and cold process that. They got rid of them. Now, the base
24:11 stock that goes into good quality mineral oil, and that would be American
24:17 Petroleum Institute Group 3. - API, people, if you ever see that, we'll get to
24:25 that in a minute. API is extremely important, particularly with the
24:30 motorcycle and clutches. Then there's questions about tappets and all
24:34 other things. API, we'll talk about that in a minute. Go ahead.
24:38 - Yeah. These advanced, they're not refining processes. Refining is taking
24:49 out the defective parts and what's left behind is good. The new method of making
24:55 mineral oils actually reforms the molecules. It breaks those nasty
25:00 aromatic rings open and then it attaches little extra side chains onto them and
25:10 makes ideal lubricants out of them. Because synthetics are made out of carbon
25:16 and hydrogen. They are not something uniquely special. They're just an
25:22 arrangement of their, they are a high performance arrangement or an optimized
25:29 arrangement of the hydrogens and carbons. Mineral oils are converging with that to
25:36 such an extent that the Better Business Bureau a few years back finally
25:43 announced that they would allow this Group 3 called synthesized hydrocarbons
25:51 to be so-called, to be characterized as synthetic. They're both attempting
25:59 to achieve the same thing. This army of identical six foot tall robust soldiers.
26:05 - So I have a question.
26:07 - Go ahead.
26:09 - My question is base stock. So you keep talking about base stock and I would
26:14 assume that that's the bulk of the recipe. And I've always thought, well, you know,
26:22 there's the actual oil and then there's all the other stuff they put in it to do
26:26 different things. So I'm kind of curious about like what's the base stock
26:29 percentage and then what are the other components at play? And how much actual
26:35 oil do we want in there? It's the question, I guess.
26:39 - Well, this is something that old timers who were then younger than I am now would
26:50 say. They'd say, "Give me an oil that's 100% oil. I don't want none of them
26:55 additives." All right. Here is an example of a spark ignition mineral motor oil.
27:05 It is 77.6% base stock. So it's two or three quarters of it, a little more than
27:12 three quarters of it is the base stock.
27:14 - Oil.
27:15 - Oil. Then 10.9% is noodles, the viscosity index improver.
27:25 - Getting our 2050 out of something. So we got a 20% base.
27:28 - You bet it. You bet. And then 6.5% is ashless, which means not containing metal
27:36 in this case. Ashless dispersant. And you can think of a dispersant as opposed to a
27:43 detergent as being a sort of molecular trash man with hefty trash bags who's able
27:53 to stuff them with unwanted things like soot particles, either from a diesel engine
28:01 or from a direct injection automobile engine, direct cylinder, what do they call
28:06 it, GDI. And these people, they love that stuff. And then 2.5% metal-based detergent.
28:17 And a detergent, like a soap, forms a monolayer all over the surface of anything
28:25 that it finds. And that monolayer prevents it from sticking to other particles. So
28:34 it's very good protection against sludging. Because sludging, oh, here are some other
28:41 sludge particles. Let's form a club. Let's build a house. And they build that house.
28:50 It's marvelous to see an engine that has been run on nothing but pure oil. And I did
28:56 this when aviation author Graham White and I started to take the accessory drive case
29:05 off the back of a 28-cylinder Pratt & Whitney aircraft engine. We finally took off all the
29:13 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
29:24 a gantry crane in your shop. - I did have. It's a weakness. But I've
29:30 overcome it. I went to a help group and I've been able to come back.
29:39 - Come back on your 4360s and your gantry cranes.
29:42 - Yes, sir. Now, let's go further through this list. 1.4% inhibitor, which is basically
29:50 anti-corrosion stuff. And then 1.1% anti-wear, which is a stuff that protects metal surfaces
30:03 when the parts are not moving rapidly enough to develop a full oil film to separate them.
30:11 The anti-wear forms a solid lubricant layer wherever there is a very high temperature
30:18 from local friction. And that layer is shearable. The friction in that layer is from 1% to 10%
30:31 of the friction of dry metal on metal. So it's a very useful reduction and it prevents
30:39 the scoring and scratching that you would have otherwise. But anyway, back to this point.
30:44 - VDVP, we should... - Yes, VDVP. Let us all join in unison to
30:49 say zinc dialkyl dithiophosphate. - 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
31:08 the back of the engine and it was solid sludge. It looked like gravy. And just as Graham put
31:17 his hand into it, I was calling out, "Sharp things!" And he cut himself because stuck
31:25 in that sludge were all the little curlicues of metal that this engine had generated over,
31:30 I think when that one came apart, it looked like it probably had best part of a thousand hours.
31:37 - Oh. - But all this horrible sludge. And I took
31:41 apart a '40 Chevy engine and it was black, just horrible sludge.
31:47 - Yeah, it had a 58 Triumph that was horrific. The bottom of the oil tank was sludge that
31:53 was this thick. Now I want to pause because you called it gravy. And gravy is another
31:58 important lubricant that we... Don't disparage gravy. Gravy's great. And in the past, Kevin,
32:06 we had a long email chain going many years ago. It was called the Excellence of Butter. So
32:10 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 - (laughs)
32:23 - Mouthful of dry chicken, you swallow that thing and it can just decide, "I'm staying here."
32:29 - Yep. - Mayonnaise.
32:29 - Viscosity index, very important. - Yes, sir.
32:33 - So anyway. - So you were saying
32:36 - What about the sludge? - Well, the thing about sludge is
32:40 eventually hard balls of sludge detach from the clubhouse and plug things up. They can plug up
32:48 little oil ways and so forth. But I did some videos with a CBR 600RR engine, Honda, that had
33:03 26,000 miles on it. I took that thing apart and I was gonna bow down and worship, as you mentioned
33:10 at the outset here, because it was beautiful inside. No sludge. All the oil holes that I could
33:18 see were nice and open. And I'm sure that if I had applied oil pressure to where the pump sits,
33:30 that oil would have spouted out of all of these little holes, as it must in order for the thing
33:37 to last like that. The engine was beautiful inside. And of course, what happens is that
33:42 things like the detergent and the dispersant round up all the bad guys and herd them off to the
33:49 filter where they're stopped. And the really little stuff, of course, you see that the oil
33:56 turns black with time if you don't constantly change it. Some of those wear particles and
34:03 sludgy stuff is in the oil and goes out with the oil change.
34:08 So the answer is, here we've got roughly 22% additives in this spark ignition motor oil.
34:21 And I think that's a fair estimate for any of the oils that we would put into a motorcycle engine.
34:28 And it's very much worthwhile having an anti-corrosion that prevents what happens.
34:36 Anybody who's ever taken apart an old two-stroke, that is one that's not been
34:41 ridden for two years, knows that the crank is likely rusted. And so that having that
34:51 anti-corrosion stuff in there means that your camshafts are going to be as bright and shiny
34:55 as the ones in that 26,000-mile engine that I took apart. And there are long lists of these
35:02 additives, and there are wonderful mouth-filling chemical names for all of the ingredients. And
35:09 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
35:23 making its way through hard steel. So there's a lot to know. If you want,
35:32 the books are all waiting for you. Well, one thing I want to ask,
35:40 what we haven't addressed here is how does oil work? And you kind of implied, oh, ZDDP works,
35:47 the zinc works by forming a film at high temperature. Classic car and classic bike people
35:54 want that flat tappet protection of cam rolling up on the flat tappet. So maybe explain
36:05 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 back side of...
36:20 It's the front side to you people, but we're driving up the back side 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.
36:35 Oh, we're hydroplaning. Well, what's happening in hydroplaning is that the tire is pushing
36:43 water ahead of it until the thickness of that film of water in front of the tire becomes great enough
36:52 to support the weight of the vehicle on that tire. And this is exactly what happens when
37:00 you start your engine and all the moving parts, such as the pistons sliding in their bores,
37:07 the crankshaft journals turning in their bearings, and the cam lobes and tappets
37:13 trying to grind one another down, is that they hydroplane on a lovely film of oil,
37:22 and the bearings, all of these encounter groups are designed so that...
37:30 to favor the formation of this wedge-shaped oil film. So if we're looking at a journal bearing,
37:38 the outside of the bearing and the bearing shells are nice and round, and in the midst is the round
37:48 journal of the crankshaft, the load pushes the journal slightly off-center in the bearing,
37:57 allowing an oil wedge to form. And the rotation of the journal drags the oil, because it has viscosity,
38:09 it can drag the oil from the low-pressure zone, which is constantly being filled up with fresh oil
38:16 by the oil pump, into the loaded zone, where it does its good work. And in that loaded zone,
38:25 the closest approach of the journal to the bearing can be a couple of microns.
38:29 A micron is a millionth of a meter. So it's wicked thin.
38:35 Wicked thin, but 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
38:47 on a hydraulic turbine in a small rural dam, generating a little bit of electricity for the local folks,
38:55 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,
39:12 the original hand scraping marks on those tilting pad thrust pieces were still there.
39:21 In other words, nowhere at all.
39:24 Amazing. Well, that's what we're going for, right? That's why we want to pick exactly the right oil
39:31 and put it into our bikes, because we want it to have nowhere. We want it to be as beautiful at
39:36 30,000 miles as it was when it was 1,000. We do. And the thing is that the only thing that is
39:44 supporting the load when you have complete film, hydrodynamic lubrication they call it,
39:50 is the viscosity of the oil. It doesn't respect the name of the oil's manufacturer,
39:57 the name of the molecular species. All that counts is viscosity, namely that the motion
40:05 of the parts can sweep oil into the loaded zone fast enough to separate the moving parts from
40:14 each other. Just as when I got to 58 miles per hour, the tire climbed up on the water film and
40:21 the engine tacked up. Yes. It was wonderful. And if I slowed down to 55 miles per hour,
40:31 it was perfect. No problem. So what has happened? What has changed that we've gone from 2050,
40:41 like my Velocette would want 2050? Yes, it would. But our Toyota 4Runner wants 020. Now,
40:50 what is going on? Yes. Well, what's going on is that years and years ago, Junior Johnson
40:57 became greatly impressed by the amount of horsepower that was lost by the crankshaft
41:04 transferring kinetic energy to oil. And he wanted to reduce the amount of oil that was flying around
41:12 in the crankcase. So he went to the specialist guys and they said, "Well, you could tighten up
41:22 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." So then he asked the next echelon of people, older people
41:35 who had other experiences. And he found out that during World War II, the manufacturers of
41:42 large aircraft engines wanted to reduce the amount of valuable
41:48 aircraft gasoline used in break-in. So they said, "Let's produce an extremely fine surface finish
42:02 on the journals of the crankshaft." And they developed a method of doing this, which
42:08 was saddle-shaped abrasive stones, which were supported on a lubricating film.
42:16 And they would let the temperature go up and up and the lubricant would become warmer and it would
42:22 lose viscosity and the stones would come closer to the surface. And at a point they would start to
42:28 lop off just the asperities, they love to call them. The little mountains on the surface
42:34 were being ground down. And as they let the stones come closer and closer,
42:40 they could end up with a surface that was not only extremely shiny, like a crankshaft that
42:45 has been micro-finished, which is the same as polishing your shoes, but it would be truly
42:51 cylindrical. Well, I think the first motorcycle engine that I was aware of that had super-finished,
43:01 this was a wartime process, super-finished crank pins and main journals was Goldwing.
43:08 And they could put much thinner oil in there because the thing you don't want to happen is
43:15 that the rotating journal gets so close to the bearing surface, the oil film becomes so thin
43:23 that the asperities stick up and hit the journal. I do love the word asperity, I love the word
43:30 asperity, it's aspirations, right? We're pointing it up. And that's the thing is it's making the
43:37 surface so beautiful and so perfectly round that you're getting rid of that area where it could
43:43 poke through the film. It's so, so fine. So you can make the film, the film can now safely be
43:49 thinner, which means that you can use a lower viscosity oil, which reduces friction by a
43:55 measurable amount. You're not going to be able to contribute the money you save from this to your
44:02 child's college fund. It's not a significant amount, but it can be enough to get them through
44:09 all those tricky federal regulations. So that has driven the move from the old days, which was
44:17 20, 30, 40, we're in those places to the 015 business. Now, I remember talking to
44:27 Rob Muzzy about this. He said, "Oh, these oil people are in here and they got us trying all
44:34 this stuff, 015, what does it even mean?" But his further conversation revealed that he'd learned a
44:42 lot from those guys. And what has happened now is that new car and new motorcycle crankshafts
44:52 are finished to a higher standard, both of irregularity, that is asperity height.
44:59 In the Himalayas, the asperity height is very large. And out at sea, it's moderate,
45:09 and in the desert it can be. So this has allowed us to use lower viscosity oils
45:18 and at some reduction in fuel burn. And if you apply this to a whole nation,
45:28 presumably the people up there in Ann Arbor just rub their hands together in glee at the thought of
45:34 the tons and tons of CO2 they were saving us from. So good for them.
45:39 - Yeah. So I would like to finish with API, if we can do that effectively. And then what you said
45:46 earlier about following the manual for your motorcycle, the recommended oil. So tell us
45:54 about... I mean, API is something that you should do the Google research on, right? Use large...
46:01 - American Petroleum Institute, yeah. - And understand those and look at the number
46:07 that's recommended for motorcycles versus that which is used in automobiles and the different
46:12 job that oil in a motorcycle can have, including lubricating the gearbox and being in the clutch.
46:17 - What the motorcycle oil manufacturers will tell you is our oil offers more protection because
46:27 motorcycle camshafts have a more... a grimmer relationship between the lobe and the tappet.
46:35 And I'm sure that when they used to advertise after the Indianapolis 500, XYZ oil rode with
46:45 the winner, I thought, yeah, and a little two ounce can under his seat. Because...
46:50 - It reminds me of being in the pit at Laguna Seca, you know, 15 years ago to Superbike Race
46:57 and very large American motorcycle racing team had oil bottles and chemical bottles all over
47:06 their paddock. And it was all taped off. And somebody had written on it with a Sharpie,
47:12 very fast oil, your name here. They were looking for an oil sponsor.
47:16 - Very good. - It was awesome. Anyway, carry on.
47:19 - Well, I learned that anyone who wants to be an oil manufacturer can become one.
47:25 Because what you do is you order your base stock from that supplier. And if you have to
47:32 supplement the base stock with a polar molecule like an ester, you order in some from those guys.
47:40 And then you phone up the manufacturers of additive packages. Now, it often turns out that
47:49 the additive package that is designed to be soluble in mineral oil is less soluble in
47:55 certain synthetics. So there are rules that must be abided by. But there's nothing to stop somebody
48:01 from just becoming a manufacturer of oil. And they mix all, you know, it's like it's in the old song,
48:08 I'm going to mix it up right here in the sink. And they put it in cans or bottles and we buy it.
48:15 So, and the API is there to backstop things with by setting standards. And you'll see
48:24 on the oil container, the starburst that shows four-stroke engines. And then the oil
48:35 service category, which last time I looked was SN, that's probably some, it's moved on by,
48:41 like those frogs you see crossing the road at night and hops forward. And, oh, what's this?
48:48 But you can look that up online by looking for the API oil service categories.
48:56 And I'll explain it all to you. And you will be your own expert.
49:02 I think that's a great spot. You should be your own expert and, you know, apply practical thinking,
49:10 become your own expert, light the dark places. And as I think you said in Sportbike Performance
49:16 Handbook, someone asked you, or you were always posed with the question, like, how often should I
49:21 change my oil? And you said, well, there's probably some benefit to changing your oil every 10 minutes.
49:30 Yeah. But actually what goes on is that the oil has a finite amount of additives in it. And the,
49:39 what controls the, what switches on the change oil now in your car, if your car has this feature,
49:50 is an algorithm and not something that's being measured in the oil. The algorithm says,
49:56 how long has this engine spent at various conditions of operation?
50:00 Well, let me see now. And then it says, change oil now. And what that is based on is the likely
50:08 consumption of ZDDP or other anti-wear additives. In other words, when your oil is worn out,
50:17 you should change it. If you want to change it more often than that, if you want to flatter
50:22 yourself while I ride real hard, go ahead. That's fine with me. And it's fine with the oil.
50:27 The other thing that can happen is that the oil, if used too long or operated too hot,
50:35 can fall out of grade. The noodles break. When the noodles break, you don't get the viscosity
50:45 heightening effect of those long molecules that are swimming around in amongst the base stock,
50:52 like eels. And half an eel just doesn't cut it. 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. Or they say, this oil has fallen out of grade. Look for
51:14 all these failures in your engine. And that is one thing I wanted to say before we finish,
51:21 is get your oil checked. Use an immaculately clean drain pan and put the oil in there. And
51:28 there are services. It's not that expensive. They can tell you exactly what's going on. You want to
51:33 drain it out at 3,000. Like, oh, I think 3,000 is the way to go. Drain it out at 3,000 and send it
51:38 off and see what they say about it. See what's in it and how it's performing. It's not that expensive.
51:43 And then you could wait till 5,000 and do it again and see if there's a difference. And to me,
51:48 that is absolutely fascinating. But I also have a book on my desk here that says,
51:54 you know, oscilloscopes, selecting and restoring a classic. Not everybody
51:59 wants to send their oil out and you could just change it at 3,000. But use the recommended oil,
52:05 the recommended weight and the right API grade, SJS, whatever. Look that up and feel confident.
52:13 That your motorcycle will last as long as you need it to. And it will look like that CBR you
52:18 took apart with 20 whatever thousand miles. Yeah, it was so beautiful. I love that thing. Yep. All
52:25 right. Well, thanks for listening. If you like what we're doing, please hit the like button.
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