Comment by kingsuper20
5 years ago
It's a lot scarier when you see things going under load at speed. Lots of wiggling, twisty magic, waves.
Smokey Yunick (blessed be his name) used to make see-through timing covers, oil pans, valve covers + strobe light + some sort of oscilloscope setup to watch the craziness. I think I remember seeing the results for small block Chevrolet timing gears on sprint car engines as the teeth wiggled more and more with rpm. Cam went backwards and forwards. Ooof.
> Smokey Yunick
Oh, man. I'm not a huge NASCAR fan, but that guy. That guy. He was an absolute master of "But the rules didn't say I couldn't..." and probably is responsible for half the thickness of the modern rulebook on his own!
"What? The fuel tank capacity can't have an inflated basketball in it that springs a leak during the race, leaving us with more fuel capacity?"
"What? The fuel lines have to be a short path between the tank and engine? Now, look, nowhere in this here book does it say I can't stuff the frame rails with a couple hundred feet of spiraled fuel line. It gets an extra gallon or two in the car? Really? Huh..."
"Nowhere in the book does it say the bodywork has to actually match the size or positioning of the stock car the race car is based on. I can't help it if nobody else has totally redone the bodywork to improve aerodynamics... oh, OK, you're bringing cardboard templates next season, got it, that trick is done."
The guy was an absolute master of "creative advantages that weren't actually illegal at the time they were used."
The aero belly of his 1968 Camaro was interesting. The SBC-powered Indy car (probably the last of home-garage built vehicles for that race), the time he drove a NASCAR car back from an impound without the gas tank, etc.
Not to say that cheating didn't happen elsewhere. Check out the front-end sheet metal of the Trans-Am Boss 302s. Use of the headlight holes for brake ducting. The inline Autolite carb. There were some good minds at Holman-Moody, Kar Kraft, Bud Moore, etc.
> "What? The fuel tank capacity can't have an inflated basketball in it that springs a leak during the race, leaving us with more fuel capacity?"
Pardon my ignorance- what is the motivation for temporarily reducing the fuel capacity in this example? And why was it disallowed?
Fuel tank capacity is required to be 10 gallons. Say, 20 laps or so.
They check, at the tech inspection, that your tank doesn't hold more than 10 gallons. Great.
Except, once you deflate the basketball (or get creative with routing fuel lines all over the car), you actually have 11-12 gallons onboard.
Which means, at the end of the race, when everyone else has to pit, you can make the "risky option" to skip the final pit stop, keep rolling, and, well, surprise of surprise, make it over the line (in first place) before you flame out.
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Your fuel tank was only allowed to hold a certain amount of fuel because if you had more, you could go farther between pit stops, thereby covering more laps while the other drivers were stopped for gas.
He would temporarily meet the small tank regulations during inspection, but under race conditions, the ball would burst, allowing for more space in the tank, which would get filled up with more fuel than his competitors at the first pit stop.
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I assume the rule book specified a maximum fuel tank size, to ensure that teams were making roughly equal pit stops for refueling, etc. Installing a larger fuel tank with the volume taken up by an adjustable air reservoir means the tank starts at legal capacity, and increases in capacity after the race begins, allowing fewer stops for refueling.
When you qualify, your fuel tank is only allowed to hold X gallons. With the basketball inside, it held X gallons.
When the basketball sprang a leak and deflated, the tank held X+Y gallons, netting a slight advantage between pit stops (an extra lap or two over 500 miles adds up)
Fuel capacities are reduced to minimize the fire in fiery crashes. But lower fuel capacity means more pit stops, which the racer wants to minimize.
Temporarily reducing fuel capacity means the car passes tech inspection, but really has more capacity.
I suspect that it increased the fuel capacity from the nominal "max" at race start, so when you hit a pit stop you can put more in.
He also had an infamous Fiero with a "hot vapor engine" that was claimed 50+ mpg and 250hp (when the stock 4cyl made ~90hp, it was the 80s after all): https://www.legendarycollectorcars.com/featured-vehicles/oth...
Reciprocating machines are fairly remarkable when you consider all of the components involved, forces, etc. Even more so when you think about how long a typical car engine lasts.
These incredible forces are why rotary and turbine engines are substantially more reliable. Some gas turbines have only 1 moving part, and in some applications this moving part experiences zero wear due to magnetic/aerodynamic/active bearings.
Rotaries are a funny case. Look good on paper. Thermal efficiency issues. Smog. Seals. Noise control difficulties. Weird patches like bridge ports.
For modern passenger cars, it's kind of like overcoming the difficulties of two-stroke.
In anti-defense of 4-stroke ICE, it seems to me like we are hitting peak wacky complexity of those. Variable timing cams, turn off the cylinders, direct port injection, turbos, variable intake, complicated ECU. It's a far cry from a flathead 6 or VW flat 4.
Thank God electric cars are becoming more available, although I fear increasingly complex cooling and battery management and the 1000 things a software guy is going to add to them.
> Thank God electric cars are becoming more available, although I fear increasingly complex cooling and battery management and the 1000 things a software guy is going to add to them.
I'm hoping lithium iron phosphate starts to be used more in midrange vehicles; partly because they can be scaled up while sidestepping the potential resource bottlenecks around cobalt and nickel, and partly because they're very durable and cooling isn't usually much of an issue. Though heating might be an issue in the winter time (most LFP cells don't like being charged when temperatures are below freezing; heating might be necessary in winter).
Salesman of the future: "This motor's got five-phase windings with third-harmonic injection, baby!"
That actually is a thing, its only worth a few percent of power at the same size, and I totally expect to see it happen.
The problem with ICE industry is that nearly nothing improves much in absolute terms.
If you take a look at list of ICE records, nearly all of them were made decades, and decades ago.
Biggest piston engines - early 20th century
Most powerful piston engines - fourties
Most efficient piston engine - Jumo 204 held the record until nineties
Most power to weight - eighties
Uncounted billions put into engine RnD were mostly about scraping last few percents off everything above, and environmental compliance.
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[*] more reliable in theory. Mazda RX8 and rotary engines are famous for being a bit maintenance heavy and unreliable.
The amount of engineering and brain power that has gone into making common ICE engines in cars in wide deployment reliable is staggering.
I've own an RX8 maintenance came down to adding oil every few fill ups, and changing spark plugs every 10k miles. If you treat the engine correctly, the will easily get to 100k miles, if you drive the engine incorrectly (run at low RPM), or run low on oil things won't last long. The car is a sports car and won't get you worry free 200,000 miles like Accord or Camry. Even the S2000 had similar oil usage.
Talking to the dealers I took the car too, many of the issues with related to people who didn't warm engine up, or baby the engine below 3,000 rpms causing carbon build up.
Agreed on automotive rotary. It's not in the same spirit as the gas turbine and others.
Kevin Cameron from Cycle World has written some of the most fantastic articles about these topics, in particular there's one that I'm struggling to find about the problems with solid camshaft mass when rpms started to get really high and resulted in cam oscillation and failure, so they were made hollow, only to then discover they got too hot, which led to making the sodium filled, and on and on.
Also a couple of great ones about the struggle to find alloys for radial engine cylinders that could flex without cracking. His writing is so insightful and concise!
You can get clear valve covers for some BMW motorcycles now. https://www.youtube.com/watch?v=BE71lpgJ4ng
We had a see through engine w/strobe system at the uni I studied vehicle engineering at, it was really really educational to be able to adjust ignition timing and fuel mixture and see how it would change the color & shape of the flame front.
Probably a ton easier to simulate it these days but at the time it was absolute magic and really helped me understand how to ear-tune an engine to at least good enough to get on a dyno.
How much of that was really metal elasticity and how much artifacts of the camera technology used, eg. rolling shutter?
I work with metals all day every day, and damn can it flex, but would have imagined the high carbon steels used in engines would he fairly still.
i just got a driveshaft balanced for my 240z, it was 2/3oz out on the front and 1/3oz out on the tail. I was thinking how much force would that generate at speed.
Hopefully the vibration problem is gone.