MORE "NEW" Tech that's actually really OLD!

Name: MORE "NEW" Tech that's actually really OLD!
Uploaded: 2025-06-18T20:09:33+00:00
Duration: 1 h 29 min 37 s
Channel: Cycle World

Cycle World

6/18/2025

There is so much old technology people think is new that it didn't fit in one episode! So join us for our second round of interesting motorcycle and engine technology that seems new but absolutely is not. Technical Editor Kevin Cameron and Editor-in-Chief Mark Hoyer hit the podcast running with roller tappets...Listen to hear about those and the rest of the items on the list!

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00:00:00Welcome to the Cycle World Podcast. I'm Mark Hoyer. I'm with our technical editor, Kevin Cameron.

00:00:06We're doing part two of a podcast this week. A number of weeks ago we did

00:00:11essentially what was old made new. Technology you think is new, but is actually perhaps a

00:00:17century old or more. We have the second part of that list. Kindly, one of our fans said,

00:00:24I made a joke that we could do a 13-hour podcast on these if we did the whole list. And he said,

00:00:29well, get with it. It would probably help the RPM or revenue per thousand if we did it that long.

00:00:38But we know you got other things to do, so we broke it up into two. And we'll get going after

00:00:45we say thank you to Octane Lending for sponsoring this podcast. There's a link in our description.

00:00:51You can shop for a motorcycle and see what you could pre-qualify for to finance a motorcycle.

00:00:59So check it out. Click the link. We're going to start with something that is near and dear to me,

00:01:08but also far, far away. So most of the motorcycles I own have flat tappets. And there's much ado in the

00:01:16current market because oil has evolved. Everything has roller tappets. And they've tried to take all

00:01:22the, let's say, catalyzer poisoning things out of oil. And it's all like pond water now. It's all

00:01:30zero 20, zero W20. And I just rebuilt the Ford 460 in my F250 and put it back in. And we took many

00:01:41measures to make sure that the flat tappets would not flatten a cam because there is an epidemic of

00:01:47cam flattening. And you have to, you get your zinc heavy oil and you put your zinc ZDP, ZDDP stuff in,

00:01:55and then you go right to 2000 and you hold it for 20 minutes, half an hour, shut her down, make sure

00:02:01everything's good. And then you drive it and you keep it, keep it spinning. We can avoid all that with

00:02:07roller tappets. And you'd think we did roller tappets last week or five years ago, but no.

00:02:11Is it 1894? Yes. Yes. It was 1894. Holy moly. Stephen, Stephen Balzer was a Hungarian immigrant

00:02:27who trained as a watchmaker at Tiffany's. Remember the movie Breakfast at Tiffany's? And with Audrey Hepburn.

00:02:38Well, in 1894, Balzer built a three-cylinder rotary powered car, the first automobile to operate in New York

00:02:52City. And he was later contracted by Professor Langley to produce a more powerful engine for his

00:03:09aerodrome, which was going to be launched off of a houseboat floating on the Potomac. And they made

00:03:15several efforts. They developed a marvelous engine that made excellent power per weight.

00:03:24But it came to nothing because it didn't fly. It hooked on stuff as it went down the launching

00:03:33track and tore the tail off. So I think the pre-flight was missing something.

00:03:41There's a lot of, you know, you got to take care of a lot of details with an aircraft.

00:03:48Yeah. Fuel boost pumps on.

00:03:51Yeah. That's why we have massive checklists because the consequences are real.

00:03:58Indeed, they are. And then in 1908, the Sagan brothers, it looks like Seguin,

00:04:09Laurent and Louis produced the 50 Gnome, which was a rotary engine that was the precursor for

00:04:21all of the rotary engines that powered so many World War I fighters. If you've ever seen those

00:04:27flying circus movies with the daring young men and no parachutes,

00:04:34it was believed that people would jump out of their airplane rather than try to save it.

00:04:40Expensive things, these airplanes. Anyway, it had roller finger tappets, roller levers,

00:04:47and they look just like the roller lever tappets used in the first version of Harley's eight valve

00:04:55board track racer. And the last version used what they called at the time direct action tappets,

00:05:03which were parallel to and coaxial with the push rods. And they had rollers on the end.

00:05:12And the great thing about rollers, as you were just pointing out, is that they don't have to be

00:05:18generously lubricated. They can sort of squeak along until the next splash of oil comes flying off the

00:05:26crankshaft. And so thousands and thousands of those rotary engines were built for that war.

00:05:35And today we have just said farewell to the

00:05:45Harley Sportster, which had four separate cams all geared together, each one,

00:05:51each cam with one lobe on it, lifting one hydraulic tappet. And to give the Sportster those

00:06:01two pairs of parallel pushrod tubes that were a Sportster feature.

00:06:05Well, and not a bad idea on a pushrod engine so that they don't get a wave by being crossed over,

00:06:12right? If they're at an angle, they would tend to wave. And especially if they're long,

00:06:18if you really rev them up. And this is why pushrods are frequently made barrel shaped,

00:06:26noticeably fatter in the center than at the ends, in order to stiffen them up against lateral

00:06:33resonance bending. You get a pushrod whipping back and forth, you've lost valve control.

00:06:43So the roller tappet has made something of a comeback because a lot of cars are operating

00:06:52on the freeway at RPM that would produce significantly more drag on a flat tappet cam than if it were a

00:07:01roller cam. Let's talk about that. So I'm going to, I have this cap to a spray can here and we'll say

00:07:07this is a flat tappet. And then what you're doing is having the cam shaft. So I'm just,

00:07:11for you spotifiers, I'm just holding a cap to a spray can and my fist is the cam shaft and you're,

00:07:17you're turning and the tappet is in a bore and it's sliding up over the peak and then it goes back

00:07:24down and it goes around the heel where there's usually clearance. And a lot of times there's an oil

00:07:28hole on the heel that's putting oil out and allowing, allowing the flat tappet to ride on a

00:07:36film of oil until the next time the thing spins around. I have seen race engines with auxiliary

00:07:42oiling in a, uh, like a, a billet block long way drilled. And then it has sprayers at every cam and

00:07:51they pressurize that and it's just hosing the cam with oil all the time. A roller tappet puts a roller

00:07:59in between this part of the tappet and the cam and it rolls around just as it says. And, uh,

00:08:05it has the advantages advantages that Kevin has talked about. It's possible also, uh, to make hollow

00:08:13flank cams and hollow flank cams don't work with flat tappets because they'll be bridging the valley,

00:08:21uh, during one part of the lift curve. So, uh, anything that has a concavity in the cam form,

00:08:28such as the cam rings in, uh, radial aircraft engines, a ring with a series of, uh, lift curves

00:08:40all the way around it. And then the problem today, folks, for this surprise hour exam is to figure

00:08:47out the gear ratio and the number of lobes required for an 18 cylinder engine. Oh, that'd be fun. Yeah.

00:08:53Well, I have one of those rings inside the transmission of my 1966 Jaguar mark two with

00:08:58overdrive and it has an oil pump that runs on a giant ring like that and a little roller at the top.

00:09:05And again, as you spin it around, it makes the oil pressure that, um, operates the cone clutches to

00:09:12engage the gauge and disengage the, uh, planetary gear that gives you the overdrive 28% in this case,

00:09:18which is a very nice number. I got to say, when you hit that electric solenoid and it engages the

00:09:23oil pressure to the cones, it goes, and off you go 80, 85 miles an hour. What a flat tappet engine,

00:09:31overhead cam bucket shim. Yep. Do you know Aston Martin's, the, uh, Aston Martin, uh, inline six of

00:09:38the DB five, DB four, you know, James Bond and all that. Um, uh, very, very old school. So in a

00:09:44Jaguar, you put, you take the, uh, you take the bucket off and you put a shim underneath that fits

00:09:49in this nice little pocket and you can adjust your valve clearances that way, which is very common on a

00:09:54lot of, um, um, Japanese motorcycles, you know, the double overhead cam stuff that we have enjoyed for so

00:10:00long. Yep. Um, at Aston Martin's, uh, you machine the tappet, you do, you do your math and if it's too

00:10:07short, you get another tappet. Yes. You start, you start over handmade, beautiful, very English.

00:10:15Right. Until the next tappet set, uh, next clearance setting interval comes up when you have to do it

00:10:22again. And of course that was, uh, the motivation for Ducati to come up with a longer service interval

00:10:27because people were moaning about, um, having to clearance those desmo systems. And I don't

00:10:35remember, I don't remember the inner, I'm sorry, go ahead. I attended a day of service school and

00:10:42they had the special pliers that enable you to load the, uh, retainer against the split collets and the

00:10:54valve stem. So they are all fully seated. So you don't get a false, um, piece of information.

00:11:01You're measuring with the shim stock. Oh, that's good. Then you start the engine. Suddenly the

00:11:05clearance is hugely greater because those things weren't seated. So this special purpose thing,

00:11:11they had made a satisfying crunch. It's a neat system. Um, my 900 SS, I believe is, uh,

00:11:20uh, 10,000 kilometers or 6,200 miles for checking the valve clearances. Yep. I did it. Uh, as soon

00:11:28as I got the bike, cause I got it with 853 miles and I thought, well, let's just make sure we get,

00:11:32we know what we're dealing with. I got it with 853 miles two years ago in 1995. Uh, I went to the

00:11:39press launch of the, uh, super sport, uh, 1000, uh, the Pierre Turblanche design of this, the next

00:11:48generation super sport circa 98, 99. And, uh, it was at Laguna Seca and we had our presentation,

00:11:55Andrea Forney, the test rider was there and he said, we have updated the seats of this, uh,

00:12:02engine. In addition, there was lots about that engine that was improved. The castings were nicer.

00:12:06There were a lot of changes, uh, but they went to a beryllium bronze valve seat and it extended the

00:12:13interval, the, uh, checking interval. Yeah. Uh, beryllium is, don't eat it. It's very toxic,

00:12:20but it's also got a lot of qualities that we would like inside of our engines. An extremely

00:12:24high Young's modulus, which is why they made electronic racks for satellites out of that stuff.

00:12:34Wonderful. Anyway. Well, we could talk about Young's modulus, but, uh,

00:12:38yes, we'll leave that for another day. Um, but roller tappets continue to have a place as I

00:12:46mentioned in case of, of automobiles rolling along the freeway, it reduces, uh, somewhat

00:12:53cam drive friction. But of course it's like, um, anything that is planing on a liquid, it's speed

00:13:02dependent. Uh, the reason why people originally had to go ding, ding with the throttle all the time

00:13:11was to keep everything lubricated. When you, when you winged it, uh, there'd be a lot of friction,

00:13:20but when you rolled off for, as you made this cyclic performance, oil would enter the,

00:13:28the, uh, area and the thing would, would be lubricated. But if it just sat there idling,

00:13:34dumb, dumb, dumb, dumb, it would tighten up. Yeah. So back in the day, back in the day,

00:13:40we did this because we, we had terrible lubrication. We didn't have, so that's,

00:13:47I'm going to kick us into the next topic and I'm going to skip the one that's next on the list

00:13:51and go right to pumped recirculating oil systems. Ah, Frederick Lanchester, the man who invented

00:13:58everything is what Kevin called him. When you, a lot of inventions you look at that are automotive

00:14:06in nature and some that are aerodynamic, there's old Fred popping his head up again because, um,

00:14:15he never had an idea apparently without writing it down at once. And one of the ideas

00:14:21was pumped recirculating oil systems. Originally, um, you may have seen farm engines that had a grease

00:14:30cup on the connecting rod big end. Stop the engine and give the grease cup a turn and a half.

00:14:35Grease centers the bearing. You're good for the next hour. Oh, grease, grease cup on the distributor

00:14:41for the Aston Martin, grease cup on the distributor for my Austin Healy, quarter turn every whatever,

00:14:48pack it full of fresh and, and you just turned it till it's, it once it bottomed, unscrew the cap,

00:14:54pack it with grease, pack it with grease, get it in there, wipe it all off. Yeah. Grease caps. Love it.

00:14:59Ah. And of course, those were the days when your car needed service every 12, every 11,

00:15:05thousand miles or 1200 miles. And, um, people just accepted that oil change. Yes. Set the point,

00:15:13set the dwell, set the gap. Oh dear. Um, and now we've gotten used to practically zero service.

00:15:21And the temptation is to let your car run out of oil. So, well, who opens the hood? I mean,

00:15:27I don't know. I mean, we, we've got a modern, how do you do that? I got a modern Japanese four by four,

00:15:33and it's like, I can't help it. I opened the hood and I checked the oil and you know,

00:15:40we've run synthetic. I'm like, Oh, I'll see what it looks like after 8,000 miles. Cause the actual

00:15:45interval is 10,000 miles, but I feel like, well, I shouldn't, I shouldn't do that. And so I look at

00:15:49it at 8,000 miles. I'll get it at five and it looks like I just put it in. It's so clean. The oil,

00:15:56the combustion control, the ring ceiling and the chamber ceiling is so good that, uh, you know,

00:16:03and it never deviates. Like at 10,000 miles, it hasn't used any oil. I mean, nothing. Yeah. It's

00:16:09exactly where I said it. And I'm like, huh, we're spoiled. Yeah. Anybody need a drink? Try that with

00:16:15your Vela set. Well, in the early days of motorcycles, you put a couple of ounces of oil

00:16:23into the crankcase. And if you could start the engine, you rode off. And as you rode along,

00:16:32the oil would be whirled about by the crankshaft and various little troughs and holes were arranged so

00:16:41that flung oil would enter the timing case to lubricate the, uh, cams and tappets and the gears,

00:16:50uh, that drove the cam. So it was an okay system. And as its proponents argued, it said only clean,

00:16:59fresh oil touches your engine. I know what I love about those. Some of those systems is

00:17:06there was a little, uh, a little fitting with a glass dome that you could see that came up next to

00:17:13the tank or through the tank and you could see the oil coming out of a spout and hitting the glass.

00:17:19And that you knew, you knew that there was still oil by this happening.

00:17:22Yes. Whereas in the olden times, the way you could tell if you needed to give a shot of oil

00:17:29with the hand pump later, it was a foot pump because you might want your hands for some other duty.

00:17:36Uh, you're advised to look back. If it's not smoking, give it a shot of oil

00:17:41oil because these engines did not have oil scraper rings.

00:17:48So, uh, and that's why engines had to be decarbonized in those days at regular intervals

00:17:55because they threw so much carbon, the exhaust, uh, ports and so forth would be caked with hard

00:18:01carbon. It would be in the combustion chamber. You have to open it up, find your little paint scraper.

00:18:07And so you say like in the, in the olden days, so he said oil, oil scraper, that's on the piston

00:18:14separating the, the oiling area from the combustion chamber. We have, you know, compression, compression.

00:18:19And in those days it might've been compression, compression, compression, oil control, oil control,

00:18:25compression, or no oil control, as he pointed out. Yeah. And, uh, and then you need, well,

00:18:30and you need to decoke and he talks about like, this is like ancient times,

00:18:35the triumph TR seven in the late seventies and early eighties had an incredibly short,

00:18:41I forget what it is, but it's like, uh, remove the cylinder head and decoke it at like 10,000

00:18:47miles. No wonder they're out of business. They, they wanted to participate in the life of your

00:18:56motorcycle. Well, I'm all for it. I am. Yes. Well, we know that if there's a complicated way to get

00:19:03something simple done, I'm in, they didn't modernize motorcycle oil systems. So we're told

00:19:11because they thought it would make them too expensive and people would say, forget it. I'm

00:19:17not going to join the motoring generation, but eventually it was such a shock, uh, that recirculating

00:19:28oil systems, uh, were accepted for motorcycles and, uh, Harley Davidson gave their 61E of, uh, 1936,

00:19:43um, such a system. And the following year, having one year's experience with it, they decided to

00:19:50convert all their models to recirculating oil. So, um, um, once it, once it was properly looked

00:20:00at by the industry, they decided, well, this, this is a great advantage. Let's, let's have it. Why

00:20:05haven't we been doing this for years? Well, thank goodness. Cause look at us now.

00:20:10And of course, in those days, there were no filters. There were no oil coolers. Um, it was just, uh,

00:20:19moving the oil around, making sure that oil was getting to the big end bearing through drillings in

00:20:26the crankshaft or through, um, pickup rings on the flywheels, a variety of supposedly, um, money-saving

00:20:36partial solutions were adhered to. Well, I'm going to go ahead and say it, Kevin. When you,

00:20:42when you have roller bearings and all that, you don't have to worry about asperities as much.

00:20:47Yeah. Ding. As long as sand isn't entering the engine somewhere. Well, yeah, they were,

00:20:55I mean, you know, back in the day, open rockers, I mean, everything was kind of exposed. You had

00:21:01tappets that were just sitting there doing their thing. You could just look at them going

00:21:05and yet when, when, uh, Rudolf Schleicher built his OHV BMW, it had rocker covers. It was a modern

00:21:18engine in terms of, of lubrication. It had a pump recirculating system and you didn't have to

00:21:25lubricate the rocker arms with a little point point, a little oil can. And why didn't that catch

00:21:35on? Well, you know, it's no, it's a rider aid though. You know, like he, oh, yes, that's right.

00:21:42I need, I need to oil my rockers while I'm riding or else I'm not actually in control of the motorcycle.

00:21:51That's it. We did a rider aid podcast. You should go listen to it. I'm being a little glib here, but

00:21:55it's true. Yeah. All right. Spline shafts. We're moving on to our next topic. Spline shafts. Now,

00:22:03splines are great. And if you've ever worked on a British motorcycle, uh, and you set the,

00:22:08you set the gear on the magneto, there's no key. It's just a tapered shaft and you just go,

00:22:16you're supposed to tap it with a hammer to set the taper and then scooch it down. And that's supposed

00:22:22to keep you, uh, in time until the next time you got to check it. And sometimes they would say,

00:22:28it may vary a little bit during the first 50 or a hundred miles, but she'll come right soon.

00:22:39Wishing will make it so.

00:22:41Tell us about spline shafts.

00:22:43Well, uh, for a variety of purposes, it was desirable to have

00:22:49something on a shaft that was, uh, unable to rotate, but could slide axially.

00:22:57And a good blacksmith could forge a square shaft and make a, uh, a wheel or, or a potential gear with

00:23:07a square hole in it. Another possibility would be a key way. We know that all those early

00:23:14motorcycle engines, the main shafts, the fly wheels, and the crank pin were joined together by

00:23:19tapers and keys. And the whole thing was nutted to make sure that it didn't just completely fall apart.

00:23:27Well, uh, I have seen older machine tools in which there's a long shaft, which has had a slot milled in

00:23:39it and a piece of quarter by quarter key stock tapped lightly into that slot. And that locks the

00:23:48shaft to a gear or a pulley or something else that is free to slide along the shaft.

00:23:55Lathes needed to have change gears by which you could cut screws of different thread pitches,

00:24:05depending upon how fast the lead screw was driven by the gearbox. And so, uh, splines were a useful

00:24:15thing there because you could, you could engage certain gears and disengage others. So on the other

00:24:23hand, splines are expensive. When Yamaha were building their vertically split twins, the YDS series,

00:24:33they had splines on the crankshaft driving the primary drive. And when 1970 rolled around and they did

00:24:45R5, they did away with that. And instead they had a great big quacking key in a key slot.

00:24:54And there was never any trouble with it. To my knowledge, I've looked at a lot of those

00:24:59crankshafts and I've never seen one of those things that failed. So all of those splines that were cut

00:25:04with, with, with, I won't call it loving care with, with machine love were unnecessary expense.

00:25:14Well, I think the only thing more expensive than cutting the spline is broaching the other part.

00:25:19Yes. Well, the broach is a pretty specialized piece of work. Um, a lot of them are...

00:25:25So that's the, the female that would be, that fits the spline. Like you have a spline,

00:25:30you got to have a part that fits on it. So you cut the spline, but then you need a broach that will,

00:25:35you know, you machine a hole and the broach would go in and, and cut the teeth.

00:25:39Pull the broach through with tremendous force. And each row of teeth would have slightly taller

00:25:46dimensions than the one before it. So each one would remove a chip as it,

00:25:54until, uh, the splines were cut to full depth. Done. Well, in a, in a, uh, a primitive motorcycle

00:26:04gearbox, uh, some of the Indian gearboxes actually crashed the gear teeth into and out of, uh,

00:26:12engagement that is no longer done. That's a terrible no, no, because of course the ends of the teeth

00:26:20are quickly rounded off or broken or chipped. So this is where we get the, the description, constant

00:26:30mesh, uh, a common six speed, uh, manual shift gearbox for a motorcycle has two parallel shafts.

00:26:40They're both splined. Uh, each shaft has a combination of gears that are free spinning

00:26:48on the shaft, but are confined by circlip, so they can't slide along it.

00:26:54And gears whose position along the shaft is determined by a shift fork, which rides in a groove

00:27:02cut in one part of the gear. It's a clearance fit. So when it's lubricated, it lasts forever.

00:27:09Provided you're not one of these people that uses the heel of his boot to engage first

00:27:15and then second, third, and so forth. And the shift drum, it used to be a shift plate, but basically it's a

00:27:24rotating, uh, device with cam slots that move the shift forks in such a way that you can select first,

00:27:34neutral, second, third, fourth, et cetera. And it is sequential. You can't shift from second to fifth,

00:27:41for example, whereas with a, a, uh, an automotive style shift pattern, you can shift from any gear to any

00:27:47other. And splines are necessary for this type of gearbox, but here's the thing that's interesting.

00:27:56And that is that Indians first gearbox, which was a two speed was used on the bikes that finished one,

00:28:05two, three in the Isle of Man TT in 1911 and, uh, splines, sliding engagement members. It was all

00:28:16tremendously advanced. And, uh, that is a separate subject, which we'll talk about in a minute called

00:28:26dog ring shifting, but it has to do with movable elements that are splined to the shaft. And when

00:28:34they're put into engagement with the engaging dogs of the next, next door gear, the neighbor gear will,

00:28:42uh, lock it to the shaft also. So you can, by a combination of these movements, select all the

00:28:51six gears plus neutral. So, uh, the problem with splines and keys is that if there's

00:29:02shock and a lot of torque involved, the bottom of these slots or, or key slots have sharp right angle,

00:29:14uh, shapes. You've got a, a Woodruff key cutter, which is a special purpose rotating cutter with

00:29:23several edges. And you've got the tapered shaft that you're going to mount your ignition rotor on.

00:29:29And you lower this thing down into the metal and it cuts the key slot to the desired depth.

00:29:37You're done. But I've seen a lot of those shafts that have broken at the key slot and the crack has

00:29:46formed at, at the sharp edge where the wall and the bottom of the key slot meet. So this has led to

00:29:55the development of Involute splines. I was just going to say Involute. What do you know?

00:30:01I thought I was going to be able to bust that out and impress you, Kevin, but...

00:30:05Well, I'm impressed. I'm impressed. Um, Involute gear profiles are, are very old and they were sort of

00:30:15discovered when, um, Dutch mill operators found that gear, wooden gears naturally war to a contour of

00:30:28sort of minimum energy. And they put some numbers guys on this and they came up with some ideas.

00:30:35But the nice thing about an Involute gear or spline is that the contour of the gears flank

00:30:42goes down to the bottom of the tooth space and it is smoothly rounded. There's no sharp edge

00:30:49there. So this means a tremendous increase in the ability to withstand fatigue.

00:30:57Now we know that in a crankshaft, for example, the crank pin is cylindrical and yet it is part of the

00:31:05crank cheeks that are on either side of it. Does it flare out into the crank cheeks or is there to be

00:31:11a right angle there so we can make the bearing the full width of that space? Well, people tried to

00:31:17make the bearing the full width. The cranks developed cracks at that sharp edge, at that right angle.

00:31:26And if run long enough, they broke in half. And they said, okay, we've got to have a smoothly

00:31:32rounded shape there, just like at the bottom of gear teeth. So Involute splines have another

00:31:39advantage. And this was recited to me by Steve Scheibe, who worked so hard to make the VR 1000

00:31:48Harley Superbike successful. He said Involute splines can be rolled. They don't have to be machined.

00:31:56Oh, even better. And of course, very fine splines are found in in jet engine shafts to couple

00:32:04various parts of how do you drive the fan? You know, do you do you put a flange on the shaft and

00:32:10bolt it? Do you spline the inside? Who knows? Anyway, very fine splines and high fatigue resistance because

00:32:21they don't have those sharp corners at the bottom of the splines.

00:32:31Of course, then when you look at a motorcycle gearbox, you think,

00:32:35well, wait a minute. Yeah, we get rid of those sharp edges, but now we have to have

00:32:41circlip grooves. They have sharp bottoms. You can't win.

00:32:51Well, we can just contour and roll everything and put a radius on all of it. And it'll just take

00:32:57extra time to make it fit. Well, people do it when they have to.

00:33:01Yeah.

00:33:01And they've learned through discouraging failures

00:33:06that they have to.

00:33:07Well, it's like with castings. I mean, when we couldn't do controlled fill and all that, we have

00:33:13like a magic of metals. We've done a casting podcast you can go back and listen to. But

00:33:18castings, you know, when when we're just pouring them in a big mold and air is everywhere and you're

00:33:23getting entrained oxides, which means trapping oxides inside the casting and they would crack,

00:33:29you just made them thicker. And that's why castings wait so much. But now we have all this magic

00:33:33pressure vacuum suction. And it's amazing.

00:33:38So it's more entrained oxides. Yeah, you just make them bit. But when you can't, when you're

00:33:43not working with that, you, you know, you just make it thicker, breaking, you make the shaft bigger.

00:33:51And then you just try to cope. All right, we're going to get to our next one.

00:33:55And and this is interesting. This kind of probably led to all the cooling that we ever wanted. But,

00:34:02you know, with liquid cooling, etc. But engine oil cooler.

00:34:08Patented by Benelli in 1931 for motorcycle use. Yeah. Amazing. Well, what you find if if you

00:34:17use an engine hard, it is temperature rises. If it's an air cooled engine and it's summer,

00:34:25it rises even more. The higher the temperature rises, the lower the viscosity of the oil falls

00:34:34until possibly you reach a point at which it can no longer provide a full film of lubrication

00:34:41between the moving parts where it's needed. So what are you going to do? Well, we will put Harley oil in

00:34:47their 50 weight. That's a solution. Another solution is to cool the oil so that it remains

00:34:55at a temperature at which it lubricates well. That's a solution. And it was adopted by Benelli

00:35:02because on their race engines, they'd had the lubrication problems. It was adopted in aviation,

00:35:09where it was discovered eventually that they were 30% of the heat, waste heat generated by the engine

00:35:20was going out through the oil cooler. And because it gets really cold at higher altitudes,

00:35:28they had to have a door on the oil cooler so that they could vary the effect. And it's been known that

00:35:37the controls to those doors could fail. This is why we say with respect to machinery,

00:35:46just do everything perfectly, then you're in with a chance. So the oil cooler is

00:35:58a wonderful thing because as the people at Velocet discovered when they first circulated oil throughout

00:36:06the engine, it makes the parts of the engine that are too cool, for example, not warm enough to

00:36:13evaporate gasoline, to evaporate gasoline, makes those parts warmer. And it makes the parts that are

00:36:20too hot, such as the exhaust valve seat and the metal around the exhaust port, it makes them cooler.

00:36:29So it has a leveling effect on temperature. And this was the basis for the oil-cooled

00:36:37Suzuki GSX-Rs, the very first ones from 86, were oil-cooled because the engineer in charge of that

00:36:48aspect of the engine knew all about World War II, big air-cooled radials and how much heat they were

00:36:57able to take out of it, how much cooling effect they could get from an oil cooler, because the oil was

00:37:02everywhere in the engine. I think the most beautiful fin pitch on the early GSX-Rs,

00:37:11very fine, the finest I've seen on a motorcycle, personally. Well, they're not deep, so it's not as

00:37:17bad to have the fine pitch, I suspect. Because we're normally at, what, a quarter-inch or

00:37:23something. Yes, they are. Yeah. A quarter-inch pitch, this means the space in between the fins.

00:37:29So if you make it really fine, if they're shorter, then the air can get in there and circulate around.

00:37:33But if you have a deep fin, take your RD 350 or your Harley or whatever, getting a quarter-inch,

00:37:39it lets the air actually get in there. So that's a bonus. Yes, because otherwise it's just for looks.

00:37:46And doesn't work. So the thing about oil cooling, of course, is you want to control oil viscosity to

00:37:57make sure that you have good lubrication. And an oil cooler is a tool that can be used for that.

00:38:02Another tool, it's an oil cooler by any other name, is a deep-finned sump. When I was allowed to examine

00:38:12the RC 165 Honda 6 that was at the museum in Canada, I could see that it had had extra fin

00:38:26area welded to the oil sump. They were having a lot of trouble with engine cooling in those days.

00:38:35And eventually in 67, when I went to the Canadian Grand Prix at Mostport,

00:38:43the hot running engines were equipped with oil coolers in either side of the lower fairing.

00:38:49So when they'd pull the lower fairing loose, somebody would reach in and pull the oil coolers

00:38:55out of their slots in the fiberglass fairing, and then the fairing would be taken away.

00:38:59And the oil coolers would dangle by their hose connections. And I was so delighted to see this because

00:39:08I was a classic ignorant youth thirsting for knowledge. And here it was. I could see these

00:39:19wonderful machines. That's why I went to that race to see the Grand Prix bikes.

00:39:26And MV Augusta, as they narrowed their valve angle after 1970, they were no longer able to get

00:39:40cooling air down into fins between the two cam boxes. And so suddenly they sprouted oil coolers in the

00:39:49nose of the fairing. They drilled a hundred holes in the number plate to let this little whistling

00:39:57fingers of air come in there and cool this. But they basically had to cool the head with circulated engine

00:40:07oil.

00:40:07Well, it's also lighter.

00:40:09Whereas before they had cooled it with all these fins. Yes, pick up a fin cylinder. Those things are not light.

00:40:19So the basic goal, of course, of cooling is to keep things from getting hotter until they fail.

00:40:26And first among them is the oil. The key to everything. When for another video, some years ago, we took apart

00:40:37a CBR 600RR Honda engine that had 26,000 miles on it. We marveled at how oil was circulated

00:40:47everywhere in that engine and at the wonderful condition of the parts. Cams, tappets, pistons,

00:40:56cylinder bores, crankshaft, all looked lovely. All you have to do is make sure that there's

00:41:05good quality oil present everywhere at a reasonable temperature. What's not to like? That oil film

00:41:15between the parts prevents them from wearing. When does the wear take place? When you start the engine.

00:41:23My paternal grandfather was given a state car by Indiana. He was a state engineer and he'd had

00:41:34it up to here with cars that wouldn't stay running after they started. So he would floor it. And his

00:41:44cars only lasted a few months because he just ripped the daylights out of them with his starting technique.

00:41:51So, Sabotroop. Oh, we're coming to a big one.

00:42:00Go ahead. How many valves per cylinder?

00:42:05I guess as many as you like.

00:42:06Yes, the optimum solution is what's left after you've experienced all imaginable failures.

00:42:15But when any technology is new and fresh, you see a great variety of approaches to implementing it.

00:42:24And so during the period between 1895 and the beginning of World War I in 1914,

00:42:36the French were the foremost, but by no means the only, experimenters making engines with as many as

00:42:45eight valves per cylinder. Sometimes there would be two side valves in pairs on either side of the cylinder,

00:42:54plus valves in the head. They had valves.

00:42:59Delage liked to put their valves in like this so that their stems had 180 degree included angle.

00:43:06Because the combustion chambers in a low compression engine, five or six to one, there was room to stick

00:43:13the valves in sideways. And they tried all this stuff.

00:43:17For about 1913, three French racing drivers and a design draftsman joined together

00:43:31and chose from among these features, the ones they felt would be

00:43:40cooperative in producing a good engine.

00:43:42Peugeot built this engine for them. It had double overhead cams. It had four valves per cylinder.

00:43:57Six valves, five valves, too many. Four valves? Just right.

00:44:04Because they were small enough to cool decently. Great big valves gather a lot of heat

00:44:10from their surface area. Small enough to cool decently. Small enough to follow the cam with a reasonable spring.

00:44:19And they flowed a fair amount of air, even with the poor port design of that period.

00:44:28So, they won the French Grand Prix in 13 and, or was it 12? I don't recall. But by 1914,

00:44:40hardly any of the engines on the starting line for the French Grand Prix deviated from this new norm.

00:44:51Four valves, double overhead camshaft. And when one of the racing Peugeots happened to be wrecked in America,

00:45:00and they looked around for someone who thought he could repair it.

00:45:06Old man Miller put up his hand. Harry Miller. Harry Miller, who always was so dapper with a little

00:45:13little mustache that looked like he was something, some kind of functionary in Hollywood.

00:45:21And he did wonderful work. The car raced again.

00:45:25And that was the origin of what we came to know as the Offenhauser 4, which had the tunnel crankcase that the Peugeot had.

00:45:36You put the crankshaft in from one end.

00:45:40It had four cylinders. It had

00:45:45four valves per cylinder and double overhead cams.

00:45:49And those things were running all the way into the 70s, I think, in turbo form.

00:45:54I remember that the man we called the champion man was

00:46:06very experienced in Offenhauser stuff because he was the spark plug guy when they were developing the turbo Offey.

00:46:14So that influence from that 1912, 1913 car that resulted from those practical people,

00:46:28the drivers and the design draftsmen, considering the vast number of alternatives,

00:46:34they came up with something that was very workable.

00:46:37And so when World War I was fought in the air, many of the German engines were water cooled sixes

00:46:51with four valves per cylinder and overhead camshaft. It was the norm.

00:46:58But somebody always comes along to mess with it. And in this case,

00:47:03people at Fiat were getting ready to go Grand Prix racing in the early 20s.

00:47:10And lo and behold, they found they could get more air through a single intake

00:47:19located in a hemispherical combustion chamber.

00:47:24I'm not sure they knew why, but we do now that the flow coming out from under the valve,

00:47:29instead of forming a free jet, which is pinched from all sides by

00:47:33atmospheric pressure. It attached to the inside of the head, which functioned as a half a diffuser

00:47:43to allow velocity in the intake stream to become pressure. It made an efficient flow situation.

00:47:53And the Fiat 405 or 6 engine was very successful. And suddenly everyone was doing it.

00:48:05And among them were the originators of what would become the Jalera 4. It was given two valves per cylinder

00:48:16and a 96 degree valve included angle. Big one.

00:48:23I was so thrilled in those days to see a Jaguar cylinder head with the two cam boxes jutting out that said,

00:48:31I am racy. They're beautiful. They are beautiful, even if they're wrong, but they weren't wrong then.

00:48:40They're only wrong now. So, uh, this suddenly four valves were out, two valves were in and everyone was doing it.

00:48:51Until Honda had a special problem. They built a four cylinder racing engine

00:49:00to win the Japan's great volcano race, which was the Suzuka eight hours of that period, the 1950s.

00:49:12And it took place on a cinder surface where the rear tire was constantly bouncing. And so was the tack needle.

00:49:22In this period, two valve MVs frequently had only 300 RPM between peak power and valve bounce.

00:49:32That is bouncing against the piston crowns. So this was a problem, a mechanical problem.

00:49:42They needed an engine that could tolerate this over revving without wrecking itself.

00:49:49And one of the things they tried was four valves per cylinder. Hot damn, it worked.

00:49:54They could make it, uh, able to tolerate a two or 3000 RPM over rev and keep right on, uh, going.

00:50:08So the Europeans, meanwhile, were looking down their noses at this deviation from the known truth

00:50:17and saying, well, clearly, uh, the news about airflow hasn't reached these distant lands.

00:50:30But in fact, the people in the distant lands knew that they could combine

00:50:35as much airflow as they needed just by making the valves bigger.

00:50:39They could make the bore a little bit bigger and Honda kept doing it.

00:50:42Yeah, it's a surprise here we come.

00:50:47Until at the end of Honda's period in, in Grand Prix racing with their air-cooled engines,

00:50:54what had been a one-to-one bore stroke ratio became 1.4.

00:51:01And this is why, uh, I so much wish that I had had some conversation with Shoichiro Irimadri,

00:51:11because he was one of the people that pushed this trend, bigger bores, uh, to make room for valves big

00:51:22enough to flow the necessary air and using four valves because it gives better mechanical control of valve motion.

00:51:29Even in the sneered at pent roof head.

00:51:35So, uh, 1961 Formula One cars went to 1500 cc.

00:51:42So, how are you going to make, if there ain't no replacement for displacement, what do you do?

00:51:50You rev the daylights out of it.

00:51:52That's what you do.

00:51:53You perform the power producing cycle more times per second.

00:51:57And so they're looking at Honda and they're saying to themselves, maybe these people from distant

00:52:05lands are a lot smarter than we thought.

00:52:08Why don't we build one of these four valve things?

00:52:11We won't tell anyone about it in case it fails.

00:52:14That way we won't look like idiots.

00:52:17So they tested it.

00:52:19They made it work.

00:52:21And soon everyone was building four valve Formula One engines.

00:52:27And then along comes Keith Duckworth, a man filled with self-confidence,

00:52:34but seeking knowledge in a genuine way.

00:52:38He tried for two years to make his engine, two valve engine, burn well, burn quickly by using squish alone.

00:52:49Then he came up with his four valve, narrow valve angle, flat combustion chamber.

00:52:57It burned fast because if he got the downdraft angle of the intake ports right,

00:53:04and got the velocity in those ports right, that high velocity would go into the cylinder,

00:53:11strike the far cylinder wall, go down to the piston and form a tumble motion.

00:53:15They called it barrel motion at the time, and they didn't tell anyone about it for a couple of years

00:53:25because it was the secret of their success.

00:53:28There was Matra in France with four valve cylinder heads and wide valve included angles with a great big intrusive piston dome poking up in there,

00:53:41like a hand that said, air motion, stop.

00:53:49And in still air, it took 45, 50, 60 degrees of ignition advance to burn it.

00:53:56And all the time that that burning gas is trapped between the piston crown and the combustion chamber,

00:54:03heat is roaring out into the metal and being lost.

00:54:09Heat that could have been keeping the gas at high pressure, pushing pistons.

00:54:14So, how can a weak little V8 with not enough valve area somehow win the races?

00:54:27Gradually, it dawned on them.

00:54:30And then they found out that it was a good solution for emissions because quick burning means efficient burning.

00:54:40You're not wasting as much heat because you're not keeping it contained this long.

00:54:46You make less knocks, too.

00:54:48Yeah.

00:54:48And now that four valve flat combustion chamber has become the standard of the world for cars, light trucks, and motorcycles.

00:55:00We humans try to drive nails with our foreheads, but eventually someone invents a hammer.

00:55:08And we're saved.

00:55:09And in this case, the savior was Keith Duckworth, whom I greatly admire, if you didn't know that already.

00:55:21So, because he was an experimentalist, he was not an austere theoretician with his head in the clouds.

00:55:32He was in the dino room breaking parts, which is how progress is made.

00:55:37Despite the SAE's efforts to interest us in simulating the entire world so that we'll know the time of our own death.

00:55:50The simulation will be so accurate.

00:55:52Have we covered that subject?

00:55:58I think we did it, yep.

00:56:00All right.

00:56:00Well, we've already gone a little bit through the transmission with our spline shafts and shifting and all that, but we do have dog ring shifting.

00:56:10Well, the great thing about dog rings is that that was how the Indian gearbox in 1911 worked, when with a two-speed, they won the Aliman 123, confounding the English establishment, Matchless and Company, and leading to a series of great match races, which were long remembered.

00:56:38But the thing about a dog ring is, instead of having to move a heavy gear lengthwise along a shaft, all you're moving is this little ring that's splined on the inside.

00:56:55It has a groove for the shift fork to engage it, and it has dogs on both faces.

00:57:01And imagine my surprise when confronted with a BMW 1800cc flat twin engine completely disassembled on a clean sheet on the floor.

00:57:19And I went over, and I looked at the shift forks, and I thought, those look, no, that can't be.

00:57:30So I picked one up.

00:57:32Yes, it was aluminum.

00:57:34So I went over to the engineers, and I said, huh?

00:57:40And they said, oh, yes, this is the way we do it now.

00:57:44We found ways to make this entirely practical.

00:57:50Because we, at the dealership, people would come in and say, it don't shift good.

00:57:55You mean, sometimes shifting from first to second, it jumps out of gear?

00:58:01Yeah, how did you know?

00:58:03Because the first to second shift has the largest difference in RPM, and the greatest amount of force, because the pinion is small.

00:58:14So the gear dogs hit with a terrible force, and they bang each other into roundness, so that instead of going together, they bounce off of each other and make your toe buzz as you try to force it into gear.

00:58:32So this will work especially well with automated shifting systems, which are using a motor drive to operate the shift drum, to select the gears, and to operate the clutch.

00:58:52And there's software to make this all work.

00:58:55And if you are a purist, you can shift with the shift lever, which is in the normal place, and in that way, your vital fluids will not drain away, leaving you a dry husk of your former self.

00:59:14But if the burden of all that purity should become, at any time, too heavy, you can let it do it itself.

00:59:27And I particularly like the idea of lightweight shift forks, lightweight dog rings that move quickly into gear rather than ponderously and slowly.

00:59:40We saw a lot of shift forks that were burned blue and black from people tramping on the gear lever to force it to go into second.

00:59:57And if it just goes in, there's no need for that kind of theatrics.

01:00:03Yeah, we're going to have to get you on the full Magic Gearbox rebuilding tribal knowledge thing.

01:00:10We've got to get you to...

01:00:11Oh, the tribal knowledge.

01:00:13We should get that written down so we can make our XS650 shift properly.

01:00:19Oh, yeah.

01:00:20Well, they're straightforward things.

01:00:22We'll talk about it another time.

01:00:25But dog ring shifting probably dates back to machine tool gearboxes.

01:00:31And to people who were using that kind of thing every day.

01:00:38Well, here's an idea.

01:00:39Let's do it this way.

01:00:41Oh, yeah, that'll be great.

01:00:43We don't have to cut as much metal driving that long multi-tooth brooch through each gear to produce the splines.

01:00:55So, dog ring shifting was something adopted recently by Kawasaki.

01:01:03I think BMW are using dog rings.

01:01:05Maybe many others have switched over, too.

01:01:07Yeah, I think the short-lived, more modern Kawasaki entry into MotoGP had a dog ring MOX, which they then adopted for the H2, the supercharged H2.

01:01:17H2?

01:01:18Yeah.

01:01:19H2 and H2R, those had dog rings.

01:01:21I wrote the test in 2015 on the street version of that.

01:01:26It was a remarkable ride.

01:01:28You don't want to miss a shift with a turbo or supercharged engine because there's so much pressure trying to accelerate the crankshaft that if the shift doesn't go through, something may be lost.

01:01:42Yeah, I called it the world's fastest pressure cooker because there was an intake temperature indicator.

01:01:49It's compressing the air into the engine, and it would make 250 degrees inside the intake.

01:02:01It's pretty hot, so you can cook a chicken.

01:02:04And this is what charge air coolers are for.

01:02:06People call them intercoolers, but they're not, unless they're between the stages of supercharging, if there's a multi-stage supercharging system or turbo system.

01:02:18But what they do is they cool the air so that it makes detonation less likely.

01:02:28And in aircraft engines, charge air coolers were common.

01:02:35And if you look at pictures of Miller race cars, you will see sticking out of the right side of the rather long hood on those classic looking race cars, this folded over finned aluminum casting.

01:02:56It's just how the air gets from the supercharger to the intake ports, and with some cooling effect on the way so that you don't deliver all that heat into the engine to assist the chemical reactions that lead to knock, knock, knock, knock.

01:03:14And melt, melt, melt, melt.

01:03:16Yes, destruction.

01:03:17All right, next up is, let's see, what are we going to do?

01:03:21We're going to go to, well, I'm a big fan of engine balancers.

01:03:26Let's hit engine balancers.

01:03:27Okay.

01:03:27One way to balance a single is to have another single pointed the other way and geared together so that the pistons move in opposite directions at all times.

01:03:42And that's what a BMW flat twin is.

01:03:44It's a self-balancing arrangement.

01:03:47Another way to self-balance is to make a 90 degree V twin that is balanced at 100% of the reciprocating weight.

01:03:59Now, what I do mentally to think about this is I say to myself, okay, the forward cylinder is at top dead center.

01:04:07The other cylinder is in mid-stroke, and the balance weight is directly opposite the piston that's at top center.

01:04:18So they are, in effect, a flat twin.

01:04:21They cancel each other.

01:04:23Then when the second cylinder comes up to top dead center, the counterweight is swung around.

01:04:28And so it is opposite that cylinder.

01:04:31So that cylinder is now a kind of flat twin.

01:04:35Self-canceling.

01:04:37In a four-cylinder engine with a flat crankshaft, that is two up and two down, primary shaking is canceled by the fact that two pistons are rising when two pistons are falling.

01:04:50But what do you do about a single?

01:04:52You add weight to the crankshaft at 180 degrees from the crank pin, and it shakes up and down less the more weight you add.

01:05:05But at the same time, now it starts to shake horizontally when it didn't shake horizontally before at all.

01:05:14So what you're doing is you're moving the shaking force out of the vertical and into the horizontal.

01:05:21And because British motorcycle frames were springy this way and more rigid horizontally, they would balance them not at 50% or 52%, which is normal for automotive engines, which cuts the peak load on the main bearings in half.

01:05:41But at 65% to 85%, so essentially you moved the shaking force out of the plane that is unpleasant, makes your feet hot, makes your hands numb, and moved it into the horizontal plane where you don't feel it as much.

01:06:03And which is why the front wheel on your British motorcycle will shake for an act.

01:06:09Back and forth in that classic way.

01:06:13And this is one of those things, like the boiling point of Mercury.

01:06:17When you see it, you think to yourself, God is in his heaven and all's right with the world.

01:06:23So, I mean, you have to rely on something in this information age, something besides information, namely what you can see.

01:06:36So, old man Lanchester, who invented everything, said,

01:06:41Why don't we build two eccentric weights that rotate, and we'll gear them together so that they're 180 degrees apart.

01:06:53So now, as they rotate, the lateral components of their rotation will cancel,

01:07:01and all that will be left is a straight line back and forth shaking force.

01:07:06Well, that's what we could use to balance the piston, which is going back and forth in a straight line.

01:07:14We tried adding weights to the whirling crankshaft, and all it did was move the shaking force direction from vertical to horizontal,

01:07:23which can be useful in certain cases.

01:07:26In Britain, the plan was, let's never retool.

01:07:30The Yanks will buy anything, just keep making the pistons bigger.

01:07:34It came to an end in the 1970s, but it worked for a while.

01:07:40So, Lanchester's idea was to create a straight line oscillating force that was very similar in character,

01:07:49had a similar waveform to the piston shaking force.

01:07:54And all the world's little four-cylinder banger car engines have Lanchester second-order balancers in them.

01:08:04In my little Korean-made car, they're down in the crankcase and they're driven by a chain.

01:08:12And they don't say anything to me.

01:08:14They don't show up on OBD-II codes.

01:08:18They just do their job.

01:08:20It used to be called four-cylinder buzz.

01:08:23And it doesn't exist anymore because it's been taken out.

01:08:28Now, where does that come from?

01:08:30It comes from the fact that if you attach...

01:08:35Okay, we've got the connecting rod with the piston attached to it.

01:08:41If we now move the connecting rod to one side, the piston falls.

01:08:48If we push the connecting rod back so it's straight up and down, the piston rises to its maximum height.

01:08:53If we slide the rod over here, the piston falls again.

01:08:58So that rod angularity is slightly changing the piston height twice per revolution.

01:09:06That is secondary shaking force.

01:09:10And Lanchester reasoned, well, I'll take my rotating eccentric weights and I'll gear them to second order, rotating twice the crankshaft speed.

01:09:22And that's what he did.

01:09:24Away went four-cylinder buzz.

01:09:29Beautifully demonstrated in the Honda Blackbird, the CBR 1100XX.

01:09:35Yes, because...

01:09:37That was a...

01:09:38You make them bigger.

01:09:39Make the pistons bigger and the shaking force gets bigger.

01:09:43The engine is the same size as before, so now the engine is shaking more.

01:09:47And you, the rider, are wondering why they put a man on the moon and they can't smooth out this engine?

01:09:55Give me a break.

01:09:57So, Lanchester, 1902.

01:10:02Still with us.

01:10:02Good on them.

01:10:03Yeah.

01:10:04Well, that Blackbird, man.

01:10:06It was a beautiful bike.

01:10:07Silky, silky smooth.

01:10:09Lots of power.

01:10:10Very peppy.

01:10:11And, you know, good juice.

01:10:14It was good.

01:10:14Like peppy.

01:10:15Yep.

01:10:17So, that deals with secondary balancers as well.

01:10:21Both the cause, which is rod angularity, modifying the piston height, and the cure for it.

01:10:30Namely, a balancer that produces a straight line force at twice the crankshaft speed, because rod angularity changes twice per revolution.

01:10:41Okay, now we have, yeah?

01:10:46Well, we're going to combine hydraulic brakes and disc brakes, because that's what we all enjoy today.

01:10:53Yeah.

01:10:54That's true.

01:10:55We do.

01:10:55There have been a lot of attempts to make four-wheel brakes.

01:11:00A lot of ills were blamed on them.

01:11:02Oh, just like when you rode your English bicycle and your friend told you, don't touch them front brakes.

01:11:08You'll go right over the handlebars.

01:11:09Well, then why are they on the bicycle?

01:11:13Well, I don't know.

01:11:14Well, here comes Duesenberg, enters four cars for the 1921 French Grand Prix, and there were some ups and downs in getting the entries accepted and so forth,

01:11:33because do we want those colonial boys coming over here to our culture?

01:11:41Anyway, through thick and thin, Jimmy Murphy wins the 1921 French Grand Prix with hydraulic drum brakes on all four wheels.

01:11:54In early practice, the brakes worked too strongly on the front wheels, and they thought, are we going to have to disconnect them?

01:12:03Then we'll be just like all these other guys.

01:12:06So somebody said, where's the hacksaw?

01:12:09Yeah, it's in the top of my box there.

01:12:11He saws a chunk off of the brake lining on the shoes, the front brakes, and it worked.

01:12:20Reduced the braking effect.

01:12:21How much should I cut off?

01:12:24About this much.

01:12:26Not too much, because you might want to take off more.

01:12:29You can't put it back.

01:12:30Harder to put back.

01:12:31So they won the race, and hydraulic brakes were validated.

01:12:38And, of course, cable or rod-operated brakes continued to be manufactured for many years after that.

01:12:45But the technology was validated.

01:12:48It was proven to work.

01:12:49And in the 1950s, when DKW were racing their 350 triple two-stroke, two-strokes don't have any engine braking, so it had these huge drum brakes.

01:13:05The easiest way to operate them and make them powerful enough was with hydraulic operation.

01:13:10So hydraulic brakes on bikes, roughly 1953, DKW.

01:13:18Those German engineers went through an educational system that was fomented by the evil uncle of the Germanic Empire, namely Otto von Bismarck.

01:13:34And even though his backers were pulling their beards at the idea of ordinary people reading books, what if they read the wrong thing?

01:13:47Bismarck said, if you want an industrial revolution like the one they had in England and the power that it gives the state, you're going to have to teach everyone to read.

01:14:00And they did.

01:14:02They created a system of higher technical universities in which everything was related to basic principles so that it was perfectly clear to those to whom it was perfectly clear.

01:14:19In this country, that didn't include me.

01:14:24I had to get in the shop and see about it.

01:14:29But there were some wonderful theoreticians that came from this educational system, and they continue to come from it.

01:14:36So good going, guys.

01:14:39No replacement for taking it apart, though, Kevin.

01:14:42Yeah.

01:14:43Well, seeing it, you talked about going to see the Honda Grand Prix bike, because you've got to see it.

01:14:47Yeah.

01:14:48Getting in the room with it or picking up the shift work.

01:14:53And better yet, having Knobby Clark tell me all about it.

01:14:56Yeah, that's solid.

01:14:57He said, when they ran the engines with the valve cutouts in the piston crowns, fresh and sharp, they made less power than if you went in there with a grinder and smoothed that all out, which reduced the compression somewhat.

01:15:13But it made those sharp edges, but it made those sharp edges slow the gas motion down less, interfered with it less, so the combustion was more rapid and less power was lost to heat flow.

01:15:29So this leaves us with disc brakes.

01:15:35Who do you suppose was an early propounder, proponent of disc brakes, Frederick Lanchester?

01:15:491902.

01:15:52Amazing.

01:15:52I like to think of Chuck Berry, who was invited to Chicago for a gig there, and he took two weeks and wrote most of the songs for which he is remembered today.

01:16:09Rousing, good, fun music.

01:16:12And it came out of two weeks' work.

01:16:18And I think that we see the same thing with John Britton, who said that he liked to work in five-week stints.

01:16:27There are a lot of people who work in odd ways.

01:16:30They don't just get up in the morning and make coffee and then make a few phone calls to arrange their lunch party.

01:16:39They've got stuff to do.

01:16:42They're thinking of things.

01:16:44They're making it happen.

01:16:46John Britton told me about how he came to make carbon fiber wheels.

01:16:53It just made sense to him to do it the way he did it.

01:16:57And when he took them to the New Zealand vehicular safety outfit, and they tried to wreck the wheels in their standard way, they failed to wreck them.

01:17:12The wheels worked because John thought about it.

01:17:16Oh, I can't do it this way because then this bad thing will happen.

01:17:21And he just kept thinking about it.

01:17:23He didn't, he wasn't thinking about calling up an old girlfriend and seeing if she's still interested.

01:17:30He wasn't thinking about a banana split after lunch.

01:17:34He was thinking about carbon wheels.

01:17:38And carbon wheels are with us today.

01:17:42So there's some value in that thinking.

01:17:45And it isn't that these people like hard work.

01:17:48For them, thinking is play.

01:17:51Play is human activity that has no negative consequence.

01:17:59And is undertaken just for the pleasure of it.

01:18:03So much theoretical math comes from this mental play.

01:18:09And so much good engineering.

01:18:12People are willing to think about it.

01:18:14Build a test rig, see how it works, refine their ideas, and get somewhere with something that works.

01:18:26Aha feels pretty good.

01:18:28Yeah.

01:18:30Disc brakes.

01:18:32The great thing about disc brakes is they can't get away from the friction material.

01:18:36A drum brake can expand away from it.

01:18:38It can cone away from it.

01:18:44External contracting brakes.

01:18:48The external contracting friction material prevents cooling air from reaching the drum.

01:18:53So, but a disc brake is exposed to the air, and it's pinched very firmly by pairs of pieces of friction material with hydraulic force behind them.

01:19:07There have been mechanical calipers built, but not to much effect.

01:19:14Oh, they were popular on bicycles for a while.

01:19:17They had a lever, the lever on a screw, and you pulled your cable, and it pulled the lever, and it, you know, screwed the pad onto the disc.

01:19:28Yeah, that could work, particularly if it was a ball screw.

01:19:32A ball screw would be good.

01:19:33So, with that in mind, the idea that the disc can't get away from the force of the friction, because it's balanced on either side of the disc.

01:19:48Yeah, so both pistons are squeezing, or even on a sliding pin, you still have a pretty balanced squeeze.

01:19:55The F-8F Bearcat piston fighter carrier plane first flew in 1944, and it had disc brakes with triple piston calipers.

01:20:10And originally, they were mounted at the bottom of the undercarriage leg.

01:20:16And they found, do you suppose a carrier plane occasionally yaws the moment before the wheels touched down?

01:20:26And then, would the wheels receive a lateral impulse?

01:20:32Well, yes.

01:20:34And if the brake calipers are at the bottom, it means that the deflection of the disc is going to knock the pads back.

01:20:42So, they move the caliper to 90 degrees to the undercarriage leg, and in motorcycling, we call this radial-mounted caliper.

01:21:01Same thinking produced by the same ill effect.

01:21:06Well, yeah, exiting a corner with a little bit of a little bar shake.

01:21:10Oh, gosh.

01:21:12Honda did with either the 9, I think it was the 954, but they coated the front caliper pistons with some low-friction coating that was meant to help your brake feel and so forth, give you this really fine feel.

01:21:26But also, it made them slippery, and that bike was a little bit more prone when you got some shake to knock the pads back.

01:21:32Yeah.

01:21:32And then you go for the lever.

01:21:33So, it became a habit.

01:21:37We balled one up.

01:21:38One of our guys did crash it, but we got in the habit of checking.

01:21:44You just give it a little, you exit, and you just like a little breathe.

01:21:47So, I thought that was wonderful that on the F-8F, they had to adopt radial calipers, radial-mount calipers.

01:21:57There's a lot wonderful about an F-8F.

01:22:00Well, yes, it's basically an R-2800 with as little airplane as possible attached to it.

01:22:08Yeah, it was sort of 0 to 40,000 or whatever, 0 to 30,000 feet in five minutes or less.

01:22:144,500 feet per minute initial climb.

01:22:18Yeah, good one.

01:22:19They had one flying out at Palm Springs a few years ago, and whoever the pilot was was giving it the beans.

01:22:27He'd come by, and they would whistle on a dive, and he was coming by it.

01:22:30It had to be 300-plus miles an hour.

01:22:34And then he would climb, and you say, well, that doesn't look right, because he would just disappear so quickly.

01:22:42Yeah, real small.

01:22:43Old propeller plane, you know.

01:22:46So, the F-89 Scorpion also was given disc brakes, and that was later.

01:22:57That was 1948.

01:22:58They first flew.

01:23:00And then by 1953, the word had got round, and Dunlop produced disc brakes for Jaguar's C-type racing sports car.

01:23:13And Duncan Hamilton and one other gentleman, whose name escapes me at the moment, won the 1953 24 Hours of Le Mans with that car.

01:23:25And the description went like this, the Mercedes, with its enormous and very beautiful thin aluminum drum brakes and a huge aero brake behind the driver that was lifted up by some hydraulic mechanism to produce aero drag.

01:23:47Flat plate drag, flat plate drag, drag coefficient of 1.0.

01:23:53So, they're braking, brake, brake, brake.

01:23:56They're approaching the hairpin.

01:23:58Here comes the Jaguar C-type.

01:24:01Still on full throttle.

01:24:02Well, looks like he's going to crash.

01:24:06But no, the mystery retarders are applied.

01:24:11The car decelerates violently, darts around the corner, and accelerates away.

01:24:17And the Mercedes was unable to do anything about it.

01:24:23So, after that, drum brakes were used as bases for floor lamps, very designerly.

01:24:32I'd like to have one.

01:24:35Those drums with the fins were so beautiful.

01:24:38Oh, yeah.

01:24:39And there were all these people trying disc brakes.

01:24:47There was a fellow named Bo Brinker who raced Bull Tacos.

01:24:51He had a weak twin disc system, little tiny discs.

01:24:57The calipers had originally been made as spindle brakes for machine tools.

01:25:01Colin Lister in England made a set for Halewood to test on his 500 Honda RC-181.

01:25:13I just saw this photograph yesterday.

01:25:14And our great, late Peter Williams put a disc brake on his G50 matchless 500, along with cast wheels, which he was one of the pioneers.

01:25:39And the resulting motorcycle, which is in Rob Iannucci's shop, is called Wagon Wheels, because, of course, the castings are unusual to look at for someone accustomed to wire wheels.

01:25:57He had a good running, working system.

01:26:00But about the same time, Honda came out with CB750 with disc brakes.

01:26:05So, the concept was validated, and it wasn't long before drum brakes were a kind of special purpose retarder for conditions where you don't want water to get in as quickly or something.

01:26:23Well, they worked okay, you know.

01:26:26You'd won two stops.

01:26:28They were not bad.

01:26:28But if you kept putting heat into them, it was, well, I had a 64 Cadillac that had beautiful, gigantic drum brakes, Eldorado.

01:26:38And they were power boosted and rebuilt them all in new hardware.

01:26:42And, God, they were wide and they were giant.

01:26:45And it was elegant braking, but it was also brake fade while you wait.

01:26:49Because if you did a really, if you did a really hard stop and you hit them and you were running them, because that's a, you know, probably a 5,500-pound car.

01:26:58Yeah.

01:26:59And just, you know, one or two, that's all you got.

01:27:02That was the beauty of discs, too, is they just, they, even with heat, they stay relatively consistent.

01:27:07You can fade a disc brake.

01:27:09You can have the pad friction material change with temperature or something like that.

01:27:15But it's, it's way, it's so far out, so far out there.

01:27:19Yeah.

01:27:20He turned his, his brakes into powder in, in like three laps.

01:27:25And in MotoGP, where the brake discs are carbon-carbon, that is carbon fiber reinforced amorphous carbon.

01:27:351,000 degrees centigrade is, is the upper limit for reasonable operation.

01:27:45But they've had to increase the size permitted from 320 to 340, now to 355 millimeters diameter.

01:27:56And, of course, aircraft couldn't last long with single disc brakes, because aircraft move fast, and they're pretty heavy in relation to their little tiny landing wheels.

01:28:10Yeah.

01:28:10So, what did they do?

01:28:12They built brakes that were like clutches, stacks of alternating rotating and non-rotating discs with a whole ring of hydraulic cylinders to squeeze the whole stack together.

01:28:26And, what happens if the brakes get so hot that the tires burst?

01:28:33Well, there's, there's a fusible plug that's supposed to come out of the rim and prevent that explosion from happening.

01:28:44But, carbon-carbon brakes for aircraft were developed during the period of like 71 to 76 for commercial stuff.

01:28:55And, about 10 years later, they showed up in Grand Prix motorcycle racing, and they're with us to this day.

01:29:06So, more messages from Frederick Lanchester.

01:29:13Well done, Frederick.

01:29:15Well, thanks for listening, folks.

01:29:16We're going to wrap that one up.

01:29:18We managed to set a near record for length of podcast.

01:29:23It's nearly an hour and 30 minutes, which is just a fraction of 13 hours, but very close.

01:29:31Thanks for listening, and we'll catch you on the next Cycle World podcast.

01:29:36We'll catch you on the next Cycle World podcast.