Why Steel Pistons and Cylinder Heads? Why Now?

Name: Why Steel Pistons and Cylinder Heads? Why Now?
Uploaded: 2026-02-04T18:30:25+00:00
Duration: 1 h 3 min 27 s
Channel: Cycle World

Cycle World

2 days ago

In the early days of internal combustion engines, pistons were typically made of steel, but it wasn't long before aluminum took over (thanks, W.O. Bentley). But steel pistons and even cylinder heads are coming back in special applications. Kevin and Mark dive in to 3D printed steel pistons, turbo housings, and steel cylinder heads in F1 and other racing. The guys take a deep dive into boost, piston temperature, lean burn, diesel, additive manufacturing and so much more.

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00:00:00Hey, welcome back to the Cycle World Podcast. I'm Mark Hoyer, Editor-in-Chief. I'm with

00:00:03Kevin Cameron, our Technical Editor. Today's topic is about steel, but it's specifically

00:00:12about steel cylinder heads and steel pistons, which has happened before. Steel was the best

00:00:20option in the beginning, better than aluminum in many ways, but then aluminum found its way

00:00:26into everything. Via W.O. Bentley, no less. Oh, W.O. Bentley. We could do a whole podcast.

00:00:36You're making me think about the, oh, the Invicta engine that was in the, oh, I forget what it's

00:00:42called. It's a British shooting brake wagon. And you can tell it's a W.O. Bentley design

00:00:49because it has 14,000 acorn nuts holding on all these beautiful valve covers and panels.

00:00:56Well, it's hard to make the Times of London seal like gasket material, so you need lots

00:01:02of fasteners.

00:01:04But, yeah, so steel. We had steel pistons and then we had aluminum pistons or other pistons

00:01:10with steel thing, you know, support structures underneath. And now we find out that with forthcoming

00:01:18Formula One technology and some recent developments in manufacturing that people are, again, experimenting

00:01:26with steel pistons or maybe utilizing them and also steel cylinder heads. And, of course,

00:01:32this came to light because Kevin brought it up. Over to you, Kevin.

00:01:38Well, I'll get the blame. All right. I was talking to Irv Kanemoto and he said,

00:01:45did you see the item about Ferrari evaluating and now having chosen, I guess, to develop exclusively

00:01:53steel cylinder heads. Now, Ferrari and Formula One haven't won anything for three consecutive

00:02:01years. So they and their sponsors are agitated and they want to do better.

00:02:10New formula rules coming in this year are going to allow some changes. And these are hybrid

00:02:24race cars. They have a battery, which is allowed to give something like 350 horsepower. And they

00:02:32have a turbo 1.6 liter V6. That's all you can build 90 degree V that is not allowed to give more than

00:02:43some similar amount of power so that to discourage people from just running the engine and letting the

00:02:52electric complexities ride. So the problem is that when you run the

00:03:02very high boost with aluminum cylinder head, you can have either cracking, which was quite common in

00:03:13Merlin, the engine that won the Battle of Britain, Merlin V12 aircraft engine heads, or

00:03:23you can have, in the case of the DFX, which is a turbo version of the DFV that was run at Indianapolis

00:03:33chap car races. They found that...

00:03:36Cosworth. Just for those who don't know your alphabets, that's the legendary Cosworth racing engine.

00:03:44They had a tendency to develop sort of punky metal around the exhaust valve seats. And

00:03:55there was a lot of agitation over this and casting specialists were brought in and they discovered

00:04:06ways around this, which are now called the Cosworth casting process. And it's one of those

00:04:13gentle bottom fill systems that attempts to lift the aluminum oxide that inevitably forms on aluminum,

00:04:25hot or cold, lift it as the mold fills and push it out through the vents and not to entrain it in the

00:04:34liquid metal where it acts like foreign matter inclusions, crack on dotted line.

00:04:43Well, there's another aspect to the deterioration of certain metal alloys, not just aluminum. In the early days of

00:04:55gas turbine power, the British actually had meteors flying during World War II right at the end.

00:05:06And they found that the hot section parts, typically turbine blades, were losing their properties over time.

00:05:17And when they studied this...

00:05:20Play on three shifts, will you?

00:05:24When they studied this, they found that the metallurgy that they had planned for this material, which was the precipitation as the metal cooled and as it aged, of intermetallic compounds of great hardness and rigidity.

00:05:45But as time passed, as the jet engine was getting more time at temperature, what was happening was that

00:05:57the very fine particles produced in this way were joining together to form coarser and coarser and fewer particles,

00:06:08so that the material became not up to the work anymore.

00:06:15So, oh, emergency, stop everything.

00:06:18We're going to let these engines run so many hours at such and such a temperature, and then they will be disassembled, all the blades removed, and they will be reheat treated.

00:06:29Now, try telling that to the airlines.

00:06:32Well, let us thank aircraft for being so critical.

00:06:36Like, I can drive a British car, I can ride a Norton.

00:06:42Would you fly in an aircraft built by Norton?

00:06:45I don't know.

00:06:46Like, you like how mission critical, like, you know, they're pretty good, but you like how mission critical aircraft is and that they would have to do this.

00:06:55And then also put all the shifts on finding the solution to not having to do this.

00:07:01Because governments are the big racing team in the sky.

00:07:06Well, that's what Dan Gurney said.

00:07:08They have the money.

00:07:09Yeah, Dan Gurney said when they shifted over to doing aerospace at All American Racers, he said that the government is a very good customer.

00:07:20Turns out, he said.

00:07:24Yeah.

00:07:25So, this phenomenon of the coarsening of material over time, of coarsening of a precipitate within a metal alloy, is called Ostwald ripening.

00:07:40And the common occurrence that we ordinary mortals who are not metallurgists, who are incapable of speaking to normal people because what they say is incomprehensible.

00:07:55If you let ice cream sit in the freezer, not quite cold enough for a fairly long time, it develops a coarse, granular, unpleasant texture that makes you go to the store and buy fresh ice cream.

00:08:12So, that is Ostwald ripening.

00:08:15And when it happens in metal alloys, it causes them to gradually lose their properties through time at temperature.

00:08:24So, this got tremendous amount of study.

00:08:29And they found ways to slow or completely stop Ostwald ripening in gas turbine blades.

00:08:37And I believe that Ostwald ripening was one phenomenon that was implicated in the DFX punky aluminum around the exhaust valve seats case.

00:08:52So, I looked up.

00:08:54I'm looking.

00:08:55I'm now looking for the ice cream solution.

00:08:57What alloys and treatment can we give to our ice cream to avoid this?

00:09:00Because it is tragic.

00:09:01Yes.

00:09:02Is there anything worse than crunch?

00:09:05Oh, gosh.

00:09:07So, I looked up the material used for Merlin heads.

00:09:12And I did so because I once, quite by accident, had an opportunity to visit Jack Roush's shop.

00:09:22And I think I counted 11 manual bridge ports in that shop, indicating that lots of little touch-up operations go into NASCAR winners.

00:09:34But, in a little room off to one side were all these Berlin heads which had been crack checked.

00:09:43And the cracks had been marked.

00:09:46In one cylinder, I counted 13 detected cracks.

00:09:54And they were mostly where the sides of the chamber met the roof.

00:10:00So, where pressure was causing the roof to move up and down, causing a moment here at the junction, cracks forming in the cylinder head.

00:10:13Okay.

00:10:14I imagine that Ferrari cast their aluminum Formula One heads out of something a little more recent than high-numinium RR50.

00:10:28But the metallurgy is similar in that it contains nickel, iron, and magnesium.

00:10:41So, the intent of this material is to form a precipitate to stuff that is not soluble.

00:10:51So, you make a super saturated solution of salt, say, or sugar, and you can form crystals.

00:10:58Because that material is being precipitated out of solution, and it forms crystals.

00:11:06Well, this material is closely akin to the 2618 that heavy-duty racing pistons are made out of today.

00:11:25It contains iron, nickel, etc., but with updates such as the grain refiner titanium in very small amounts, and other changes, no doubt, in the heat treatment.

00:11:42But the object is to make something that has good strength when it's hot and does not immediately start cracking.

00:11:52Now, in 1973, with our Kawasaki 750 triples, the same pistons that had worked well the previous year were cracking above the wrist pin for bosses in 50 miles.

00:12:07And when we asked Mr. Yoshida about this, he said, oh, new type, maybe six months.

00:12:16And I thought, well, this is not a war.

00:12:21Not a war.

00:12:22That's for sure.

00:12:23That's for sure.

00:12:24So, one of the things that people did to try to get around the crack proneness of 2618, and I'm not saying that it's crack prone, but that if you are running a turbocharged engine, you're going to push the piston's surface temperature up.

00:12:48And fatigue in metals is closely dependent on temperature.

00:12:55So, they wanted something better.

00:12:58Can I make a meatheaded observation about metallurgy right now?

00:13:02Please do.

00:13:03Yeah.

00:13:04So, aluminum melting point is about 1220 degrees.

00:13:06It's pure aluminum.

00:13:07Fahrenheit.

00:13:08Fahrenheit.

00:13:09Yep.

00:13:10Chromium is 3430, 3430 degrees.

00:13:16That's pretty good.

00:13:17Iridium, like you put in your spark plugs, is 4400 degrees, roughly.

00:13:22That's why they make those fine wires, because it has such heat resistance, melt, melt resistance.

00:13:28Manganese, 2200 degrees.

00:13:31Molybdenum, as you see in your chromoly, is 4760.

00:13:36So, when we make an alloy, when we make a recipe and we add those things in, as Kevin pointed out, titanium is doing something to the grain structure and making that aluminum tougher.

00:13:47The more grains there are, the harder it is for dislocation movement to move from one grain to the next, because there's a discontinuity there.

00:13:58So, this is why being tricky with your alloys and not adding too much and, you know, there's so much, I mean, I'm not a metallurgist, but I can read a chart.

00:14:09So, what they came up with, what they came up with, what they came up with was called dispersed phase strengthening.

00:14:16I love dispersed phase.

00:14:18I like that.

00:14:19Write that down.

00:14:20The rebels.

00:14:21At any rate, what they did basically was they said to themselves, well, these precipitates that we're producing by heat treatment and alloying are subject to this horrible Ostwald ripening, even though we've got improved materials to deal with it.

00:14:42So, they, the hotter the engines get, the higher the boost, the higher the combustion temperature, the more it tends to push us back into the soup.

00:14:55So, we need a definitive big step forward.

00:15:00Aerospace had it ready, dispersed phase strengthening.

00:15:04Instead of using fine precipitates as keys to prevent the sliding of one plane of atoms over the next one, they added finely divided aluminum oxide, very finely divided.

00:15:23And there's a whole branch of metallurgy now, which is powder metallurgy.

00:15:28They want, you want to control the grain size?

00:15:31Let's grind things up real fine.

00:15:35Pack them together like you're making a snowball and then apply tremendous pressure and some heat in a process called hot isostatic pressing.

00:15:47And you can end up with some metal properties that you can't get by ordinary heat treating because you've defined these grain sizes.

00:15:57And if you don't get it, you know, if you don't give it a solution treatment where everything is all swimming around together, you can preserve those, those fine particles.

00:16:11Well, the problem was that it was really expensive to make this stuff because how do you mix fine particles of aluminum oxide into aluminum so that it is uniform?

00:16:26The kitchen mixer won't do it.

00:16:29The kitchen mixer won't do it.

00:16:31Well, in baking, they do this horrible extrusion process.

00:16:36Steve, we sift.

00:16:39Yes, we sift.

00:16:41And they could make piston size billets of this stuff at great cost.

00:16:50And I immediately thought of dispersed phase pistons when Geraldo Ferracci said at one point, when they were racing the V twin super bikes, their pistons were alleged to cost between 10 and $20,000 each.

00:17:09And of course, when, when dispersed phase hit formula one, that's out.

00:17:16That works too well.

00:17:17It's out.

00:17:18Cost too much.

00:17:19It's out.

00:17:20And MotoGP, loyal puppy that it is, came trotting after the little, the little license tag jingling.

00:17:34And they have a rule against dispersed phase.

00:17:39So they came up with a new conventional alloy with a new system to prevent asphalt ripening from defanging the precipitates that had worked so well in 2618 up to a point.

00:17:59And they developed this material, which unfortunately, they can't make it in cylinder head sizes.

00:18:06They can make it in piston sizes.

00:18:08So it may be the follow on material for these extreme turbo engines.

00:18:16Now, back to the Merlin for a moment, the people in air racing are running boost.

00:18:23That's just inches of, of mercury over a hundred inches, maybe as high as 135 inches.

00:18:36So several atmospheres of boost.

00:18:39Originally the Merlin at the end of the war was making 1750 horsepower.

00:18:46And I think there were some that were at 2000.

00:18:49They want to make, they want to make 4,500 horsepower.

00:18:57Now, it's quite a thing when a little Merlin, 1650.

00:19:04Well, 27 liters.

00:19:06Yeah.

00:19:0727 liters.

00:19:08150, 1650 cubic inches can leave behind an R4360, 4,360 cubic inches, but air cooled, which is a terrible handicap.

00:19:22Anyway, one of the other possibilities to be used for highly stressed parts in internal combustion engines is compacted graphite iron.

00:19:38So what this means, normal cast iron can be quite brittle, not terribly strong, stronger than aluminum, but nothing like steel.

00:19:52Because it has all these cartridge, graphite flakes in it.

00:19:57And the cavities in which the graphite flakes are hiding, make nice reservoirs for oil, which is why iron cast iron liners have, have lasted so long.

00:20:12Not everything in the world is, is nicosil yet.

00:20:18So they could make heads and they have often made cylinder blocks for highly turbocharged engines out of this combat compacted graphite iron.

00:20:31The graphite is there, but it has been enticed to form fewer and larger particles so that the material is not full of dotted lines on which it may crack, but has just these compacted graphite locations throughout.

00:20:52Have you seen the photographs or videos of turbocharged engines on dinos in dimly lit rooms?

00:21:00Where the Inconel, they use Inconel, which is a really, really high zoot kind of, you know.

00:21:05There's a whole family of Inconels.

00:21:07Inconels, yeah.

00:21:08It's a cut above stainless.

00:21:10There's stainless exhaust systems.

00:21:12And then when you're really into it, you do your Inconel and they just glow.

00:21:16So you're, you're, you're trapping all of this heat to turn that impeller to compress the intake charge.

00:21:22And normally you just want to get it out.

00:21:25I could, I could take a moment and bring up that Ford 460 again, which the factory exhaust system is tremendously restrictive from the cat back.

00:21:34Never mind the exhaust manifolds themselves.

00:21:37They run it at 10 degrees before top dead center for your factory ignition setting.

00:21:41So it's pretty retarded and it runs hot and then it doesn't get the exhaust out and it warps the exhaust manifold.

00:21:47So that is a huge thing on 460s.

00:21:49And that's not even a turbo, but you're trapping it all in there and, and all the pressure in the cylinder.

00:21:55Imagine, imagine all the things happening in there, Kevin.

00:21:59Well, a friend of mine did better than imagine them because he was a service manager at a big out west motorhome dealership.

00:22:09And they had to deal with, it was a social problem as so many tough engineering problems are.

00:22:16The owner of this beautiful new motorhome is furious because he has two cracked exhaust manifolds as a result of not wasting any time getting out where the national parks have really tall mountains in them that make wonderful photographs.

00:22:36And he had to deal with these people again and again and again.

00:22:42Yes, we have the parts in stock.

00:22:44No, it won't be ready in half an hour.

00:22:47It'll be ready tomorrow morning.

00:22:48We can give you a list of hotels where you'll be very comfortable.

00:22:53So, yeah, Gale Banks, Gale Banks and Doug Thorley headers, stainless steel, tri-Y, big tubes.

00:23:06The Y pipe really gets, it's stainless, number one, and it just gets the heat out and they just, there's no restriction there.

00:23:13The Gale Banks system for a 460, whole thing, three inch all the way back.

00:23:18You just get it out, no more heat, no more warps, nothing.

00:23:22Just stainless steel, bolted up, no gaskets, it's perfectly machined and away you go.

00:23:27Solutions.

00:23:28Now, steel pistons are reused in diesels and they are invading the smaller bore applications

00:23:39because there's so much turbocharging of small diesel engines now.

00:23:45And what happens is that the combustion chamber is in the piston crown and it has a sort of a sharp edge at the entry to this chamber.

00:23:56And it cracks.

00:23:59The aluminum ones crack fairly readily.

00:24:04And so, the temptation is to switch to steel pistons of the kind that are used in large heavy duty diesels

00:24:12because the small, formerly light duty diesels are becoming heavier duty as they put smaller, lower friction engines into great big cars

00:24:23and turbocharge the daylights out of them to make them go like they've got a 460 under the hood.

00:24:29So, those are some hard working little engines.

00:24:32In 1940, one of the aircraft engine manufacturers tried steel pistons

00:24:40because they were having so much trouble with aluminum pistons scoring and ring scuffing.

00:24:48Their real problem was the cylinders were too hot.

00:24:51But if a steel piston would have fixed it, they would have run that happily because it solved so many problems.

00:24:59But the crown ran too hot and detonation raised its ugly head.

00:25:09So, no steel pistons.

00:25:11Well, diesels are a great application for stress because the compression ratios are like 14 to 1 or 18 to 1.

00:25:17They're pretty high up.

00:25:1816 is typical.

00:25:19Yeah.

00:25:20And then the boost pressures easily could be 35 psi.

00:25:25And then if you're really hammering it, you can go up to, you know, 50, 60, just stuffing it in there.

00:25:30So, it gets hot.

00:25:34I think the difference between a thermostat on a car, you know, the difference between a 180 and a 195 is significant.

00:25:42Under the hood, it really makes a difference.

00:25:46And so, every degree you can control and get rid of.

00:25:53Well, now we can come back to Ferrari and Project 678.

00:26:03They started out trying to develop improved heads.

00:26:07They seem to have decided, this is what they're saying, that the steel heads are the choice now.

00:26:15And I don't know what method of fabrication they will use.

00:26:20It might be that they will be 3D printed in metal.

00:26:26Steel has wonderful properties in comparison with aluminum.

00:26:35And it should be nice and stable.

00:26:39And in Formula One, each of the four engines that each driver gets for the season has to do six races.

00:26:54Practice, qualifying, etc.

00:26:59So, I think that's hard duty for aluminum material in a highly turbocharged engine.

00:27:07So, I'm not surprised that they're looking at alternatives.

00:27:13Now, there's some wonderful Honda material from their Formula One programs on the internet.

00:27:20And one of those sites talks about 3D printed steel pistons.

00:27:32In the very early days of the internal combustion engine, the pistons were cast iron.

00:27:39The railroads made everything out of cast iron.

00:27:41They were very adroit at casting thin sections of cast iron.

00:27:46They knew how to make the molds and so forth so that they got good parts.

00:27:50So, you would naturally go to them.

00:27:52And you wouldn't think of aluminum because you knew that the iron pistons were sometimes glowing red hot in the center,

00:28:01which means aluminum would just blow through.

00:28:05Ultimately, it didn't because it was so much better than iron at conducting that heat away to the cylinder wall in all directions.

00:28:16And that was what W.O. Bentley discovered years and years before World War One,

00:28:23when he decided to put aluminum pistons in a little car that he was importing from France.

00:28:30Not only did the pistons work well, they increased power.

00:28:35Because since their crowns ran cooler, when the air entered the cylinder on the intake stroke,

00:28:44it was not as much heated by the hot piston crown.

00:28:48And therefore, its density was higher when the intake valve closed and compression began.

00:28:53So, just changing the piston material increased power.

00:28:59Not a huge amount, but measurable before 1914.

00:29:05So, steel pistons in turbocharged Formula One seem to be pretty attractive.

00:29:20But again, it's not going to be a simple matter of going down to your local foundry and say,

00:29:25I want you to pour some steel for me.

00:29:27What do you got?

00:29:29It's going to be expensive.

00:29:32Yeah, the Honda article was fascinating printing the turbine housings for the turbo.

00:29:37And they show it at the back of the engine with a big pipe coming out.

00:29:40You can see this massive turbine housing.

00:29:42And of course, they want it to be thin wall and perfect.

00:29:47And, you know, they're using the laser welder and they're depositing the material.

00:29:53And then the laser hits it and then they have a certain amount of air blowing over the stuff.

00:29:58But it can't be too much because it deforms the molten stuff and it makes a defect.

00:30:04And so, they spent a lot of time making this extremely precise.

00:30:08And same with the pistons, you know, making the bottoms of the pistons and just enough material.

00:30:13That's really engineering, right? Engineering is truly doing just enough to get the job done.

00:30:18So, of course, we can make a piston that's incredibly strong, but we can't run a five pound piston.

00:30:24I mean, we could, but we'd prefer not to.

00:30:26At 15,000 RPM.

00:30:28We just want it to be just heavy enough to do the job.

00:30:32As you said about aircraft once, light enough to fly, heavy enough to get there.

00:30:38So, engineering in a nutshell, folks.

00:30:42Well, the material that was developed, this MS-31 material for pistons, I think was a follow on when dispersed phase was banned for excessive expense.

00:30:59And the MS-31 material is powder metallurgy.

00:31:04So, so are high pressure turbine discs in large fan engines for aircraft.

00:31:13Are we not in this case with the steel cylinder head and steel pistons, perhaps, are we not treading toward the adiabatic realm by increasing all these temperatures?

00:31:27Well, this is the thing. As long as you've got gasoline, gasoline fuel, you have the possibility of detonation.

00:31:38Now, the thing that makes detonation occur is a flame front.

00:31:44As the mixture burns, what happens is that the flame front generated by the spark plug, the spark jumping, the plug gap, is tremendously wrinkled and shredded.

00:32:01So that even though the actual linear movement of the flame is better measured in inches than feet per second.

00:32:12The fact that so much area, the flame front has such large area that it spreads quickly.

00:32:19However, if you use spark ignition in a highly over square engine, you may have to use ignition timing as much as 60 degrees before top center.

00:32:35And what that means is it gives more time for the unburned mixture out near the cylinder wall to be chemically changed by heat to become a sensitive explosive.

00:32:52Now, this is long after the spark. Combustion is combust, combust, combust, combust.

00:32:57The flame front is swelling up and terribly wrinkled.

00:33:01It looks like the neck of some of those sea mammals that are so corrugated.

00:33:10They aren't even double chins. They're zillion chins.

00:33:15And that's the way the flame front looks.

00:33:18So they thought to themselves, wouldn't it be great if we could ignite the mixture faster and eliminate some of that 60 degrees?

00:33:27Because that in itself is an invitation to detonating.

00:33:31So they came up with these jet igniters that essentially have some fuel air mixture that is at an ignitable ratio, fuel air ratio, in a container that has a lot of little holes in it.

00:33:48And there is a spark that causes that to form fast moving jets of flame that go in all directions, rather like diesel injection sprays.

00:34:02They spray radially outward from the injector in many directions.

00:34:07So I think this has eased the detonation problem, but stacking on all that boost has made the problem worse.

00:34:19So an idea of how hard they worked to make pistons last under high boost is the statement in one of those Honda website papers that says that they used as many as 21 oil cooling jets per piston.

00:34:44And as you pointed out, Mark, a typical high duty racing engine piston is a nine cavity forging.

00:34:57And so if you don't squirt oil into all nine cavities, you're going to have some hot spots.

00:35:05You know, I don't have one of those on hand, but I do have this Kawasaki piston and it has none of those boxes.

00:35:11But imagine this with boxes all around to strengthen it.

00:35:15It's like the crossing of two pairs of walls.

00:35:20Yes.

00:35:21And they brace the narrow stubby little piston skirts.

00:35:25They brace the wrist pin bosses.

00:35:27They brace the sides of the disc that holds the piston ring so that it doesn't fold downward under the considerable pressure above.

00:35:37Yeah, it's not a bad point also that this is a vintage.

00:35:41This is like a Velocet piston.

00:35:42It's actually a Jaguar piston.

00:35:44But the pin is also full width.

00:35:46The pin goes to just a fraction inside of this.

00:35:50Whereas here, they're just making it narrower and narrower.

00:35:53The pin is only as long as it needs.

00:35:55The pin is disappearing.

00:35:56Yes.

00:35:57What they don't want is what used to be universal, namely that the wrist pin boss was part of the piston cylinder.

00:36:09It did not go up to the crown because that's hot.

00:36:13And when aluminum gets hot, it loses fatigue strength.

00:36:17Like our 1973 pistons, they were the same as the previous year, but now they were failing.

00:36:24They were showing cracks at 50 miles.

00:36:26And what had changed was they had milled off cylinder fins to make the engine evaporate all of its fuel during winter development when they were cooling the engines with outdoor air.

00:36:39Now, yes, in engineering, you have to think of everything.

00:36:47You can't just say, hey, here's a protocol, run this.

00:36:52Because if somebody is just being a technician and has no experience with the sounds that a distressed engine makes or the smell, you're going to wreck engines.

00:37:07So, there can't be any dummies in this business.

00:37:11They all have to know what they're doing.

00:37:13It's fantastic because physics forces you to solve.

00:37:18I mean, you can do all the design in the world with the reality of actually running the thing.

00:37:24That's why we always talk about, you know, dino parts in the ceiling, you know, engine parts in the dino roof, excuse me.

00:37:30Yes.

00:37:31You do all the CFD and certainly there's a huge amount of progress there.

00:37:35But at the end of the day, a couple of things.

00:37:38I've talked to many people in product development for motorcycle companies who say you can't believe what customers can figure out to break.

00:37:46Yes.

00:37:47Yes.

00:37:48I've heard the same.

00:37:50Yeah.

00:37:51Or just the use cases and the loads.

00:37:53District managers are full of good stories.

00:37:56You buy a few drinks.

00:37:58You might have to buy a few drinks to hear them, but they're well worth the expense.

00:38:02Absolutely.

00:38:03So basically what we're talking about here is how can we contain the physical forces at the temperature that results from exposure to very high combustion temperature.

00:38:19And just as it has done in diesel engines, aluminum is nearing its limits in these applications.

00:38:29It has been nearing those limits for some time.

00:38:33The Merlins that were lying on the table there at Roush's shop were made in no later than 1945.

00:38:41Well, and Jack Roush is a notorious P-51 enthusiast, right?

00:38:45He was very much into it.

00:38:48I think, you know, if you're that kind of person, Roush engineering, and you're building hot Mustangs and all these other stuff, of course you like P-51s.

00:38:57I mean, honestly.

00:38:59Yeah.

00:39:00That's where those Packard Merlins went.

00:39:02Yep.

00:39:03Merlins made right in the good old USA.

00:39:06You know, I got a tour of Jay Leno's garage some years ago, and I forget what power plant it was, but he had a real ancient and gigantic four valve per cylinder cylinder head for some old great grand automobile.

00:39:25Yeah.

00:39:26And it was very telling.

00:39:28I, I talked to him and I said, I said, what's going on?

00:39:32He's like, well, I just bought this, whatever it was.

00:39:34And they said it was rebuilt and they always say it's rebuilt and then you get it.

00:39:39And it's, if it was rebuilt, it wasn't rebuilt.

00:39:41Right.

00:39:42Or there's, so I always have to do this.

00:39:43We're always rebuilding this.

00:39:44And this thing has cracks all over it.

00:39:46And that's always been my experience.

00:39:48I buy the thing that's supposedly rebuilt and then, you know, a crank and an engine case and the connecting rod and four pistons and all the cylinders and everything later.

00:40:00It's pretty good, but cracks everywhere.

00:40:04And then there, there you are trying to repair that.

00:40:07Well, another thing, of course, here is, is duty cycle.

00:40:11People will say, well, Formula One is, is a drive along an English country lane compared with the top fuel.

00:40:23But top fuel engines are rebuilt every three or four seconds.

00:40:28Right.

00:40:29That is literally the case.

00:40:31If you go to, to an NHRA national, you'll see the fuelers make their run.

00:40:38And they are escorted by emergency vehicles to get the people out of the way so they can get these cars back in their work areas.

00:40:51And the underneath guy slides under there with all his tools pre loaded into his rack.

00:40:57And they tear the engine two pieces.

00:41:00And they examine all the bearings and the clutch guy has the clutch business all apart.

00:41:06The clutch looks like Kenny Augustine talked about pistons that look like they've been in a barbecue for 10 years.

00:41:13The clutches don't look much different except the temperature was higher.

00:41:18So those engines are literally serviced deeply every three or four seconds.

00:41:29But in the case of Formula One, the engine has to do four Formula One races.

00:41:37So that's some hundreds of miles on each engine.

00:41:42That's a very different duty cycle.

00:41:44Yeah, it reminds it just as as ever reminded me of something else.

00:41:48But the B-29 bomber during wartime, the engines that were being replaced sometimes as soon as 200 hours, they just swap them out.

00:41:58There was one one account that I read by a crew chief in the Mariana's islands, from which Japan was bombarded at a distance of 1500 miles.

00:42:11He said he'd never seen an engine with more than 96 hours on it.

00:42:17Wow.

00:42:18R3350 is what that is.

00:42:19A right R3350.

00:42:21The wartime 3350.

00:42:23The post war engine has no shared parts.

00:42:27Yeah, I think it was Fifi or Doc.

00:42:31It's one of those B-29s was at the AirVenture EAA.

00:42:35And, you know, they fly that thing all over.

00:42:37And that was my question.

00:42:38I said, hey, you know, during the war, you guys are these things were just like 100 hours by, you know, like, obviously, you can't be doing that.

00:42:46And I said, no, we have.

00:42:48It was cool because we had the one of the pilots and a flight engineer and a guy who's, you know, deeply intimate with that aircraft and flies it all over.

00:42:56And said that they have what they call the Frankenstein engine.

00:43:00And and they use all they use post war parts combined.

00:43:04They get like the best cases and they sort of Frankenstein the same together with what they feel is the best recipe.

00:43:09And they're not running the the boost systems to take it up to whatever they needed.

00:43:14The turbos are are are not there.

00:43:17And isn't that as you'll see, that's that's an engineering solution.

00:43:20Just take the turbos off and let's not stress this stuff as much.

00:43:23Look, because there's slow down.

00:43:26First, first of all, they're not carrying 20,000 pounds of incendiary bombs.

00:43:35And the second thing is they're not carrying sixty seven hundred gallons of one fifteen one forty five.

00:43:41They don't make it anymore and they don't need that much fuel because they're not going round trip fifteen hundred miles out fifteen hundred back.

00:43:49So the airplane just accelerates like mad and takes off easily.

00:43:54And I'm sure they do a three engine takeoff as well.

00:43:57But they also call ahead to make sure that the taxiways are wide enough and that there's enough that there's enough fuel at the airport to refill it.

00:44:07Yes. Check for existence of fuel.

00:44:12Well, and normal, I think what was the takeoff was forty three inches and fifty five was the detonation threshold.

00:44:24And so it goes.

00:44:27But it is a matter of duty cycle because the airlines wanted to run air cooled radial engines thirty five hundred hours.

00:44:38The strategic air command wanted to run them two hundred and fifty hours.

00:44:43And in top fuel, they run those Chrysler inspired engines three or four seconds and then they rebuild them.

00:44:56Boss, look at this bearing.

00:45:00So I was fascinated years ago with the clutch.

00:45:03The clutch out of the Harley Davidson, the V twin that they were running, Vance and Heinz.

00:45:09They had, you know, they'd go through the process.

00:45:12They weren't tearing those down every run, but the clutch was definitely a part frequently.

00:45:17And you can't take a picture.

00:45:20It was beautiful.

00:45:21All these clutch parts and they have little weights and stuff on it.

00:45:23And I was like, oh, that's gorgeous.

00:45:24And I wanted to take a picture.

00:45:25And they're like, don't take a picture of that.

00:45:27And because it was like their special setup and their weights and everything, they just didn't want that out there.

00:45:32So I'm like, fine, that's cool.

00:45:34But they had a tub.

00:45:35They had some wash tubs.

00:45:37And the guy, there was a guy dedicated to cleaning the clutch.

00:45:42And he would take, he'd have the stack and they'd have basins of cleaning fluids.

00:45:47And it was like dirty, dirty, clean, you know, soapy, less dirty, clean, and then very clean rinse.

00:45:56And he counted his brush strokes.

00:46:00He put it in and he was like, one, two, three, four, five.

00:46:04And then he'd do the other way and he'd flip it over and he did the same number of times.

00:46:08And then he put it in the next bin and did the same thing.

00:46:11I love that kind of, what was it, attention to detail.

00:46:15Yeah.

00:46:16Like, I want this to happen exactly the same way every time I'm touching my nose.

00:46:21I'm counting to 10, you know, you just do all those, those rituals.

00:46:27Well, I, yeah, in that, in that line, I remember that there was a well-known builder here in the U.S. who, there was a tech sticker, I think, on the bike.

00:46:43And it no longer was applicable and a helper removed it or went to remove it.

00:46:50Nope.

00:46:51Nope.

00:46:52Don't touch that.

00:46:53What do you mean?

00:46:54I don't like to change anything on the bike when it's, one, it's heat race.

00:47:02Just don't change anything.

00:47:05And, of course, sometimes there's a solid reason for that, which, of course, was the case with McDoin.

00:47:17He told the Honda men, no changes to the motorcycle unless I am informed and give my consent because I need a motorcycle whose behavior is predictable.

00:47:30That is how the motorcycle tells me how close I am.

00:47:37You wouldn't want to mess with that.

00:47:39Yeah.

00:47:40So, but I think this duty cycle thing is, is very important.

00:47:46The Formula One engines, they're asking them to run longer and longer.

00:47:51So, before they had, before they were requiring engines to last more than one race, teams were using hundreds of engines, but they weren't as thoroughly engineered.

00:48:07Their pistons weren't able to go longer distances.

00:48:11They were no better than they needed to be for the application.

00:48:16So, to save money by running engines in six races means you have to build a very different kind of engine.

00:48:26You may have to use this, this MS-31 material for the pistons or you may have to develop pioneering steel pistons.

00:48:39So, Mercedes, when they initially were building four-cylinder engines for automobiles, when they wanted to race those automobiles, they wanted to replace the cast iron cylinder and head, which were always in one casting.

00:48:59And what they came up with was to fabricate the whole thing out of steel sheet metal welded together.

00:49:08And that way they were able to save an enormous amount of weight and have parts that were, could fly.

00:49:19Because after 1914, there was a close correspondence between the Mercedes engines that won the 1914 French Grand Prix and the engines in the aircraft that British and French pilots would soon encounter over the Western Front.

00:49:40Same technology.

00:49:42Same technology.

00:49:43Same technology.

00:49:44So, those things are coveted secrets when, when they apply.

00:49:52Nowadays, it's, yeah, Formula One is pretty secret, but you don't hear of anybody spies being tried and imprisoned for violations.

00:50:05So, it's, but I'm, I'm fascinated by this, this switching to steel heads because the more I looked at what they were facing, the better I felt I understood the motivation to do it.

00:50:24Now, here's something, Moto GP for 2027 is going to say, well, we've reduced the power so much, now you won't have enough power to, to push a lot of arrow.

00:50:36We want to de-emphasize that anyway.

00:50:39In Formula One for this year, they are allowing movable wings.

00:50:45They can move from the X mode, which is minimum drag, like those huge downforce wings that were on those World of Outlaw cars, as if you just put it to, to where it didn't produce either up or downforce, minimum drag.

00:51:04And then Y mode, the Y axis being vertical, is a production of maximum downforce.

00:51:11So, while Moto GP is going away from arrow, Formula One is, is giving it a good hug.

00:51:21Yeah, what was that, the Chaparral, Chaparral 2F, was it, 2E?

00:51:26Oh, what a wonderful concept.

00:51:29Yeah, and then the sucker car was also super interesting.

00:51:33But the, we've, we've seen movable wings before.

00:51:36Oh yeah, they, they had big struts sticking up from various parts of the car.

00:51:40In some cases, the downforce was applied to the wheels and not to the chassis.

00:51:45Imagine, right on the.

00:51:46To the uprights of the suspension.

00:51:48Well, that's what, was it, Rad, Rad Greaves in, in the old Formula Extreme class wanted to put wings on his Hayabusa and he did.

00:51:57Uh, he was putting wings on the fork lowers and, uh, I think it was on the swing arms.

00:52:02We had that dog in the studio and I rode his, um, wingless race bike.

00:52:07But, uh.

00:52:09The things that he put on it looked like, um, uh, dust pens.

00:52:14Yeah, they really were.

00:52:16It had such a, he was, uh, sort of Detroit area, uh, folding copper.

00:52:22He was a roofer and, uh, loved racing.

00:52:25And yeah, he built that Hayabusa with the wings on it.

00:52:28And then as was a very common at the time, it was sort of like a, a chrome anodized type of paint.

00:52:35They were getting a very chrome like finish, uh, what you could spray on.

00:52:38And it, it had sort of blue anodized type color.

00:52:41And I'm sure it was a metallic laid over a chrome chrome like base.

00:52:46It was, it looked pretty cool.

00:52:47And there he was with his wings.

00:52:49They weren't movable, uh, but they were acting on, um, on the, uh, unsprung parts.

00:52:55He had the, he had the theory that there was not enough load on the drive wheel to keep it from spinning on the straightaway.

00:53:05And you do hear, um, riders quoted in MotoGP saying it's spinning all the way down the straightaway.

00:53:14I think Eric Bostrom said that to me on, uh, I think it was a formula extreme bike.

00:53:19I don't know if it was Bostrom, but there was an Arian bike that had, uh, quite a bit of power.

00:53:25And I heard about that at the top end where it was spinning.

00:53:27And of course that's the challenge at, um, Bonneville for almost anything is being able to modulate your power at the top end when you're starting to really crush air where the arrow is, you know, obviously rising.

00:53:39Um, the aerodynamic drags going up so steeply, you get to a point where you're exceeding the amount of traction.

00:53:46And, uh, guys I've talked to have to be very careful about throttle application on the salt to keep enough spin so that you keep driving.

00:53:56They talk about it being roughly 40% of what's available on a, on a good tarmac surface.

00:54:02So wheel driven.

00:54:11Hmm.

00:54:12We were driving across Germany and one of those, I went on a tire tour once and, uh, I saw the, the name of the Autobahn on which, uh, Baron Rosemeyer was killed testing a high speed car.

00:54:31Um, came out from behind a wooded section and a crosswind just blew them off the road.

00:54:38And, uh, I don't remember the name now of that Autobahn, but it was, um, very much in the top of my mind when I saw it on the sign.

00:54:50I, but that's, Oh yeah.

00:54:53Suzuki's test track, uh, uh, Ryugo is notorious for that.

00:54:57They have a very long back straight where it feels like you're in sixth gear for five minutes.

00:55:01It's not, but it's, it's the longest time you spend in sixth gear on any racetrack.

00:55:07Let's put it that way.

00:55:08And your mind is, your mind is racing, which makes time slow down.

00:55:11Yeah.

00:55:12So you're, you're smacked on the tank and all the light guys in front of me, there was this opening down the straightaway where it opened to the sea.

00:55:19And there was always a crosswind and they were very, you know, like, you've got to watch out for this.

00:55:23Do not, you know, don't take it for granted.

00:55:25Watch out for the crosswind comes up more in the afternoon or whatever it was.

00:55:29And there we were going and I'd be following the little road race guys.

00:55:32And I'm big, I'm, you know, 220 pounds and they'd move over quite a bit more than I would, but you'd see them every time.

00:55:39Bang.

00:55:40They just, they just move.

00:55:41Right.

00:55:42So you're trying to draft them so you can, uh, you know, get them into the next corner.

00:55:46Those small guys, those small guys.

00:55:49Well, uh, when I was doing some of the reading for this project, six, seven, eight, the steel cylinder heads for the, for the Ferrari formula one team, I'm looking at all these metal alloys and, and I'm, and the, they're talking about different processes.

00:56:12And it's all so interesting that I think I can't get old enough to, to drink this all in.

00:56:25And it makes me feel deprived.

00:56:27Here I am this ancient, this ancient character.

00:56:31And, um, the, the, what is known is streaking out ahead.

00:56:38Oh, wait for me.

00:56:39Yeah.

00:56:40But that's the way it is.

00:56:43It is the way it is.

00:56:46There was that Indian guy, uh, Indian Cooner guy, Bob.

00:56:51Was it Bob?

00:56:53Just doing his, his, uh, dirt track bikes, his race bikes and his H beam connecting rods and all that.

00:56:59And, uh, he was doing it into his nineties.

00:57:02And I remember talking to him over coffee one day and he said he was Bob Nichols.

00:57:07Yeah.

00:57:08Yeah.

00:57:09He was fired up as he, he was just so fascinated and curious and really going.

00:57:14And then he's just like, there just isn't enough time.

00:57:17You know, he was really focused.

00:57:19It's wonderful to see that kind of application of, uh, energy to something that we love so much.

00:57:27Yeah.

00:57:28Joy of motorcycling in so many forms.

00:57:30You know, what are we, we're striving ever, striving ever to make it better in some way that we think is wonderful.

00:57:37And in fact, the motorcycle is a, uh, a symbol of our desire to streak away, to get there first, to be, uh, what Mr. Honda said, primarily essentials of the motorcycle consist in the speed and thrill.

00:57:59And I thought this is printed right in this Bentley manual.

00:58:03I love it.

00:58:04Yeah.

00:58:05Um, Ben younger, a motorcycle person and TV producer.

00:58:11He, uh, he does some coaching at the, uh, champ school, uh, Nick Inatch thing, the Yamaha champions riding school.

00:58:18And, uh, he's, he said it really well.

00:58:22He said, I ride fast enough so that I can think of nothing else.

00:58:27You have to focus.

00:58:28That's what's, that's, what's great.

00:58:30There were a lot of comments after you used that phrase.

00:58:33Yeah.

00:58:34It rings true.

00:58:36It really does.

00:58:37Cause that's what it's nice when someone articulate something like that precisely to capture your feeling so that you understand that feeling a little bit better.

00:58:45Well, uh, Brian Uchida was friends with a, uh, New York literary scene gentleman who wrote poetry for the New Yorker magazine.

00:58:57And he wrote poetry that somehow was mysterious to the literary crowd.

00:59:07And what he was saying was when I'm down with the nuts and bolts of daily life, I go for a ride on my motorcycle and it sweeps my mind clear.

00:59:23Now, lots of motorcycles that I've talked to have said very similar things that the motorcycle, by requiring you to be as alert as a squirrel.

00:59:37But hopefully more thoughtful, but hopefully more thoughtful.

00:59:44Yes.

00:59:45Well, squirrels would do better crossing the road than chipmunks.

00:59:49Chipmunks don't have the processing power, I think.

00:59:52I think.

00:59:53But I think that, that quality of the motorcycle, that it demands all you can give it and thereby helps you to clean out, uh, superfluous worries and concerns.

01:00:08That's a valuable thing.

01:00:10Yes.

01:00:11Because our lives these days are not simple.

01:00:15No.

01:00:16And they are not free of anxiety.

01:00:19No, they aren't.

01:00:20Brian Uchida, just so we, we get this down for the record.

01:00:23Brian Uchida was, uh, with HRC in the United States for a long time during very glorious HRC years when there was much titanium.

01:00:32Yeah.

01:00:33So all those exotic, beautiful.

01:00:36If you walk down to the end of pit lane, there, the Honda establishment would be, and you would see Brian in there.

01:00:44Uh, doing whatever tasks he'd been assigned.

01:00:48And he had lots of interests.

01:00:51So, uh, that was, that's my pitch for the motorcycle as a way of cleaning the attic, clearing it out.

01:01:03Yeah.

01:01:04I heard dreaming described as, uh, your brain taking out the day's garbage.

01:01:10Yeah.

01:01:11Well, there are some people who are sure there must be deep meaning there.

01:01:15And if you could study it according to whichever system is in fashion at the moment, you would learn so much about yourself.

01:01:23But the skeptics like to say, oh, it's just the brain lugging out the trash.

01:01:30There's different things happen during the day and your mind puts them all together in story form.

01:01:35What?

01:01:36You're not going to believe what I just dreamed.

01:01:38Well, I don't want to hear it.

01:01:40I liked what you said about, uh, whatever's in fashion at the time.

01:01:44My observation from study at school was, uh, they essentially you cycle through very similar ideas about things, but the next person comes along and invents a new vocabulary to describe it.

01:02:00And it sounds, it sounds somehow different and interesting and, and maybe it's new, but it's very similar.

01:02:06You know, we still work in universals and, uh, I, I do.

01:02:10What are they, what was, um, Britain's first principles.

01:02:14Is that what it was?

01:02:15Yes.

01:02:16He'd like to work from first principles.

01:02:18Makes sense.

01:02:19He said with that boyish enthusiasm of his.

01:02:23Yeah.

01:02:24And that, that last time that, uh, I talked to him, he said, I think I'm, I'm done with the, this motorcycle thing.

01:02:32Now I'm, I'm into man powered aircraft.

01:02:36That was going to be next.