F1 engines did 20,000 rpm in the ’90s? Honda’s did it in the ’60s
Hang around car people for more than a few hours, and the conversation turns to engine sounds and exhaust notes. Everyone has their personal favorite, but a few soundtracks are favored by almost all. One is the characteristic scream of a V-10 Formula 1 car, whose engine’s crankshaft spins at nearly 20,000 rpm. The insane howl of these cars, which raced between 1989 and 2005, is a wild thing, but nearly three decades before, a motorcycle engine spun just as fast . . . with four fewer cylinders.
The six thimble-sized pistons in the engine of Honda’s 1960s-era RC166 bounce up and down at a frequency that puts each piston at top-dead-center over three thousand times per minute. Piston speed is in the range of 68 feet per second.
But, you say, most of the motorcycle engines during that era of Grand Prix racing were two-strokes; with no valves to operate, that kind of engine speed isn’t as impressive.
Wrong. Well, at least kind of. Most bikes of the ’60s were, but the 250cc RC166 had a double-overhead-cam four-stroke engine. Soichiro Honda was putting all of his company’s racing and production eggs in the four-stroke basket: He believed it, not the smoky and cantankerous two-stroke, was the future.
Since a two-stroke engine has a power stroke on every revolution of the crankshaft, and a four-stroke has a power stroke on every other, Honda engineers used additional cylinders and rpm to smooth the power pulses as they went back through the bike’s transmission and were eventually absorbed by the tire.
One of those power pulses likely wasn’t significant by the time it reached the contact patch; each of the RC166’s cylinders displaced merely 41 cubic centimeters. For scale, the combustion chamber of a Chrysler Hemi V-8 displaces 85 cc. Despite these minuscule pistons and valves, the engine in Honda’s RC166 produced nearly 65 horsepower. With Mike “the Bike” Hailwood holding the handlebars, the RC166 handily won the 1966 and 1967 Grand Prix championships. Sadly, after ’67, Honda put its motorcycle GP program on pause, switching focus to Formula 1, where it worked to scale up some of the engine technology that it had used to create such dominant racing motorcycles.
The RC166 will always be remembered for more than its spec sheet; it was a wild feat of engineering that actually worked. Hearing its screaming exhaust note is just a reminder of what is possible when an engine designer puts their mind to a task.
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I think you mean 850 cc per cylinder on the hemi.
He said “combustion chamber” of a Chrysler Hemi V-8 but my lawnmower can put its piston at TDC “over three thousand times per minute.”
Per cylinder the displacement for a 426 Hemi would be roughly 875cc (7000cc total divided by 8 cylinders.) The 85cc is only the volume of the combustion chamber in the cylinder head.
You failed to mention the other Honda GP bikes that were fielded at the time. I remember a 50cc/4 banger the also won that class & turned over 20k rpm. I believe they also had a winning 125cc /4 DOV turning in the same RPM range. They were the pinnacle of GP motorcycle racing at the time that was the time. When they brought out the Honda 450 cc dual overhead cam street bike the CB 450 also known as the black bomber because of the butt ugly tank.
I was stationed in Okinawa at the time in the Marine Corps and bought the very first Honda 450 that hit the island. It was one awesome bike at the time.
I had one also, 1967, guess I pushed it up to 13,000 rpm one time too many and the right side con rod came out the front of the cyclinder, wiped the trans also.
“…a two-stroke engine has a power stroke on every revolution of the camshaft…”
Got my shafts mixed up. Fixed it. Thanks for pointing it out.
It was in the mid sixties that I was at the Ulster Grand Prix outside Belfast … just 14 or 15 years old. Mike Hailwood was battling Agostini riding an MV Augusta. In the pits, the Honda had a very unique exhaust note. You didn’t need to be near the bike to hear the sound. When the throttle was first cracked open, it sounded like a dog bark, but then changed to the sound of an angry tea kettle when the RPM skyrocketed. Great to have been able to be there for that.
20k rpm is pretty crazy
Memories-Oakland Airport 1960s motorcycle races. A thumping Norton Manx goes by at full chat in the straight followed by the incredible RC166 with a rather shrill 20K RPM scream.
Don’t forget the 125 cc five-cylinder Honda racer, if you’re talking thimble-sized pistons.
Wow: Metal parts spinning at 20k rpm, right there by the family jewels.
-But who thinks of consequences when you’re racing.
Ten years before the RC166 Moto Guzzi built and raced a 500cc V8, DOHC, 12000rpm. Perhaps some of the Guzzi Otto technology made it into the Honda.
Ford’s SHO V6 did 11,000 rpm on a test stand at SVO in 1989 . . .
and the motor actually got put in a Road Car that drove to the Grocery Store. Of course it was limited to about 7500 on the street to keep the Alternator & AC Compressor from coming through the hood.
I think my COX motor in my model airplane would hit 30,000 . . . lol
The “Ford” SHO V6 was designed and built by Yamaha.
I love seeing how everyone thinks that RPM isn’t impressive for that time (or even now!),Yet…………..Honda bike engines (UNLIKE ALL 4-wheel vehicle engines) can endure those impressive RPM’s and STILL be more reliable than any 4 wheeled vehicle out there! Your welcome.