Inventor catalytic converters

The Gainesville Sun. As far as I understand it, ideally one would want a backpressure wave for optimal scavenging during valve overlap on a four cylinder engine. Free flow of exhaust isn't a great idea, as one coul. Phony advertising claim. They also whiten your laundry, freshen your breath and improve your sex life. I agree. However, compared to other emissions reduction technologies retarding timing, CVCC, etc. Cleaning up emissions after combustion allows engine designs that are more fuel efficient, but higher in emissions, while still achieving the same results at the tailpipe.

This is particularly the case for NOx emissions. So while the catalytic converter doesn't improve fuel efficiency itself.

It can be an enabler of other fuel efficiency technologies. This graph [energy. Higher compression ratios yield higher efficiency, both theoretically and in reality. However, high compression ratios typically result in higher NOx emissions. You can see that compression ratios reduce and level off when stricter emissions standards come into effect in the s. However, once catalytic converter technology was well developed, compression ratios began to increase once again. You're not wrong.

In fact, the higher the octane rating, the less energy you get per liter, but it's almost insignificant. Long ago engine designers and builders learned that higher CR Compression Ratio result in higher power and efficiency. In gasoline and alcohol engines you want combustion to start when you cause an electric spark in the spark plug. But higher CR can result in preignition and detonation, which are a result of heat and pressure.

Preignition and detonation are a bad thing and even s. Mixing exhaust back into the intake system cools the combustion and reduces NOx, but obviously you lose some power and efficiency. EGR is actually a means of keeping combustion chamber temperatures steady when reducing fuel burned. It reduces NOx by reducing oxygen, since the exhaust has less of it than a fresh intake charge. If you simply injected less fuel for a given amount of air, NOx would go up.

I've always heard and read that NOx is created by peak temperatures, therefore cooling combustion reduces NOx. Regular 87 octane is just fine. I refuse to own a car that requires at least As many miles as I drive, fuck that gas bill!

I had a car for 13 years that required Back when I bough it, 91 was regularly 20 cents more per gallon than The increase in compression ratio, resulting in better fuel economy, made the situation pay off economically.

However, a few years later, gas stations stopped advertising their price on high octane fuel. Instead of being 20 cents more per gallon, it was often as much as 1 dollar more expensive than regular I put up with it for a few years, and then sold the car. I'll never buy anoth. It permits a small richly charged volume to ignite a larger, leaner one.

But it was only a carbon reduction technology, it increases NOx [google. Ultimately, instead of mandating the desired result, that is reduced emissions, regulators mandated the technology. This closed of any further innovation. I am of the opinion that things would be very different if the government just told us what it wanted, instead of telling us what to do. This is unfortunately a side effect of the way governments operate. Regulations are not written by law makers, or experts in the field, they are written by lobbyists.

Lobbyists don't care about the end result, they only care that you use their client's product to get there. Most laws would be far better off talking about end result rather than method of achieving it, but that's not how laws will ever likely be written. You want reduced tailpipe emissions? Don't say "you must use X technology to achieve this". They may come up with a different technology that achieves the same goal, in fact it may even end up being better, but because you said they had to use X that can never happen and you're stuck with that one technology and no real progress beyond it.

If I were king I think I would abolish all lobbyists. That or establish a law that there would be a People's Lobby, funded in equal parts by all the other lobbyists.

I think the govt. Sometimes I genuinely feel sad for the govt. Yes, but it's a bit more complicated. In the s they started adding the AIR system to some cars. As well as higher thermostat temps. It's just a small low-power air pump squirting air into the exhaust system. Annoyingly in the way, very noisy sometimes, but draws so little power BTW 2: American cars were essentially required to have cats in model year so beginning in Unfortunately, it increased NOx, so they had to go to a catalyst like everyone else to meet NOx standards.

In the 80s we used to routinely remove them, at the same time we fitted exhaust headers and dual exhausts with free flowing mufflers. Newer cars are more temperamental about such mods, but catless downpipes are still a popular mod on my current car. Not street legal in most places, but depending where you live you may be more or less likely to get caught. I bought a Vega not only the worst car that I've ever owned, but the worst car anyone I've ever known ever owned which had the catalytic converter hacked off and a splice welded into place.

When that bit of stupidity rusted out a couple of months after I bought it I ended up clamping a new splice into place with a layer of asbestos between the layers of pipe.

Every few months the asbestos would blow out and I'd have to cram some more in there. Damn that was a terrible piece of junk.

Cosworth Vegas were well regarded back in the day, but not many were made. I recall a few with transplanted V8s around here as well. I had one too when I was a teen. The stock unsleeved aluminum block engine would warp and burn oil like crazy as soon as you overheated it a bit.

My friends used to joke about how bumpy the ride was when I drove over the painted lines in the road. At one point the frame was cracked and there was no consistent position to hold the wheel in to drive straight. But it had a lot of room back there with the rear seat folded. Ah the good old days :. Between burning, leaking and just generally throwing oil everywhere it used a quart of oil a day, grass would not grow in its parking spot in the back yard for a decade.

I had to carry a 50 pound weight in the back just to keep the damn thing from sliding all over the road, and how Detroit could design a car the rusted out so fast is beyond me. I did win my high schools informal parking lot donut contest that winter, I even beat the guy with the Fiat Spyder. Learned a lot about how to fix cars that year.

Meh, modern cars' catalytic converters aren't really restrictive unless you're modifying the engine and need more flow. Even then, you can just buy a larger sized full flow cat and have no difference in performance. I would not personally do a catless downpipe as a standalone mod, but certainly in conjunction with a tuner chip and a free flowing intake.

It is amazing how much more horsepower you can get from a lot of todays stock engines with just a few relatively inexpensive bolt on mods. Yes, but you can just buy a bigger freeflow cat from the likes of MagnaFlow and have both, but again, people are cheap and catless it is. If you live somewhere where regular emissions testing is a thing I can totally see how that might be useful insofar as exhaust components are not easily swapped. The chip and the intake are much easier.

They are the primary reason your car is limited in the first place, no matter how high tech it is. In the 70s and 80s the USA couldn't figure out how to make an efficient engine. You could buy a Cadillac with a 7L or 8L V8 that didn't even make horsepower. They kept enormous displacement and kept de-tuning and adding air pumps. The fundamental problem was a lack of sequential fuel injection, which makes a massive difference.

The Japanese had that by the mid-eighties but most American engines didn't have it until the mid-nineties. I certainly don't miss carburetors, distributors with points, or any of that. Modern engines with overhead cams, variable valve timing, turbocharging, direct injection and ECUs controlling everything are obviously better in most every respect.

But one thing that has not changed is they can still be improved on if you enjoy that sort of thing. Today you are as likely to use a laptop as a wrench, but it is still an enjoyable hobby for many to mod their cars. Cats by themselves, no. But they had an important side effect: catalytic converters can't handle unburnt fuel in the exhaust gases. So when the cat was introduced, it provided an incentive to switch to fuel injection and closed-loop exhaust monitoring lambda sensor to make sure you're not injecting too much fuel.

Carburetted cars routinely dumped too much fuel into the intake. So much so that you could smell the unburnt fuel coming out of the exhaust. Thank you- I never looked in detail at cat operation. I never knew the cat broke up NOx. That explains a LOT- I've done some PCM tuning and there's a fairly big section of parameters for the cat, including that they somehow calculate guess cat temps, etc.

Now a lot of things are making sense, including aft-cat O2 sensors. Time to put thermocouple on the cat. Thanks again! The thing was put to use in the s when fuel-injection was rare. These days, engines are vastly superior that a cat converter isn't necessary. Sadly, regulation never keeps up with technology.

One unpleasant side-effect of requiring them is that they get stolen regularly in shady parts of town. They actually can't improve fuel efficiency. You need to have a sightly rich mixture in order to have enough leftover fuel in the exhaust to feed the reaction in the catalyst. Stoichiometric air fuel ratio is Typical three way catalysts operate around 0.

The only way that could make sense is if, by reducing NOx or whatever , the catalytic converter would make higher engine compression or whatever possible without increasing emissions, making for more efficient engines. Doesn't improve efficiency, however it allows us to continue to live. This is not a smart remark. I remember those days. Los Angeles used to be cloudy, all the time. Today it's nothing like it used to be. I'm in my mid 50s.

They predicted I'd be dead by now if something wasn't done. Thank goodness for the Republicans taking the lead and creating the EPA. Reigned in a lot of bad stuff. In other words, a blockage interfering with smooth and efficient flow.

Seems appropriate. On the other hand A little back-pressure is actually a good thing. From Do vehicle exhaust systems need back pressure?

As the pulses move along, they generate an exhaust flow. If you have a restrictive exhaust system, it can generate back pressure that works against the positive flow of the exhaust gas that's trying to exit your vehicle. As Jason explains, a restrictive exhaust flow that builds up back pressure is only hurting the power your vehicle can deliver because it's not working efficiently. However, a little back pressure is a good thing. In fact, it helps. The right size pipe is large enough to breathe well but small enough to create a high exhaust flow.

Steps in the exhaust system also create negative pressure waves that travel back to the cylinder and help empty the cylinder of those gases. Stop spreading this BS. It's scavenging you want, NOT back pressure.

You're correct, but it seems it's the slight back pressure that creates or supports the negative pressure waves that cause scavenging. From the article:. If the exhaust pipe is too large or missing , there won't be the conditions required to support any negative pressure and, therefore, no scavenging Backpressure itself doesn't create or support the pressure waves. Backpressure is a negative side-effect of containing the existing pressure waves in a pipe in order to create constructive interference.

Pressure waves are generated by the exhaust valves opening. Constructive interference is a product of these generated waves either merging with waves from adjacent pipes, or reflecting from the open end of a pipe. The optimal tuned exhaust is designed such that the advantage from the constructive interferenc.

He was awarded United States Patent for his work. Catalytic converters were further developed by a series of engineers including John J. Mooney and Carl D. Keith at the Engelhard Corporation, creating the first production catalytic converter in William C. Pfefferle developed a catalytic combustor for gas turbines in the early s, allowing combustion without significant formation of nitrogen oxides and carbon monoxide.

Catalytic Converters.