Could 1980s technology keep internal-combustion engines on the road?

Read enough automotive-related articles on the internet and you will be convinced the internal-combustion engine is being hunted with a fervor typically reserved for villains in Liam Neeson movies. Okay, that conclusion may be extreme—but it holds some truth. Regulations regarding emissions and engine efficiency grow stricter with each passing year and manufacturers are faced with an impossible task: Take a centuries-old design and make it endlessly better—faster, cleaner, stronger, ad infinitum. At some point, progress will plateau, and the cost of ICE experimentation will simply outweigh the incremental gains in efficiency and power. The good news? The internal-combustion engine might have one more trick up its cylinder sleeve.

Fuel, air, and spark—the three things an engine needs to run. Air is one ingredient that it makes sense to leave alone. Fuel type is essentially decided by contemporary infrastructure. (Synthetic fuels are in the works, but we’re thinking of large-scale changes in the ICE design that would extend far beyond the top echelons of motorsport to the everyman (and woman) on the street.) That leaves spark as the low-hanging fruit in this equation. If a different type of ignition could more completely burn the fuel and air mixture, it would not only reduce emissions but also increase efficiency.

Enter plasma ignition.

This is what plasma looks like compared to the sharp spark of a traditional ignition system. Transient Plasma Systems, Inc

Traditional spark ignition is very simple. A coil transforms the 12 volts from the car’s charging system into thousands of volts that discharge quickly to jump between the electrode and the ground strap of a spark plug. This forms a sharp but small zap that lights off the chemical chain-reaction that expands the air and fuel mixture to push the piston down and thus rotate the crankshaft. In order for the fuel-and-air mixture to be lit by this type of ignition system, it needs to be fairly close to a stoichiometric mixture; right around 14.7 to 1. That ratio—14.7 grams of air to one gram of fuel—puts a ceiling on efficiency. But here’s where things get interesting.

If we were able to lean out the mixture by adding air but still getting the same in-chamber expansion, and the corresponding force exerted on the piston, efficiency would increase dramatically. A lean mixture is much harder to ignite, though. So hard that you’d need transient plasma to make it happen in any reliable fashion. Technically, the spark on a standard spark plug does create plasma when it ionizes the gasses between the electrode and ground strap; transient plasma takes that small arc and dials it up to 11. If a spark plug is a zap in the chamber, plasma ignition is a TIG welder mounted in a cylinder head.

difference between spark ignition and plasma
Ionfire Ignition

This much more violent mode of ignition can regularly and predictably ignite extremely lean air/fuel mixtures. One of transient plasma’s most obvious advantages, besides a higher-efficiency combustion cycle, is that relatively low amounts of energy are used to perform a lot of electronic “work.” (The difference between energy and power, for those of you who enjoy recalling high school chemistry class.) The spark itself is not lighting a fire to burn the fuel; rather, a rapid-fire sequence of low-range electronic pulses generates a highly potent electric arc, which then breaks the bonds holding the oxygen molecules together and allows the electrons to shoot out, essentially attacking the hydrocarbons (fuel) and creating combustion. This means we are not waiting on a flame to consume the fuel and, in the amount of time between combustion and exhaust strokes, we get a more complete burn.

The most fascinating part? This technology is not new. We traced the basic concept to patents from the 1980s, but technology has obviously come a long way since then. Outfits like Transient Plasma Systems, Inc. and Ionfire Ignition are reviving the concept and the reintroduction is timed quite nicely. (If you’ll forgive the pun.) TPS ignition systems have been tested and show a 20 percent increase in efficiency while also decreasing harmful emissions like NOx by 50 percent. Numbers like that aren’t a silver bullet in the ICE gun, but plasma ignition could keep our beloved internal combustion engines on the road longer than we’d expected. TPS claims it is working with manufacturers to integrate its ignition tech into production engines, but we are still a few years away from seeing the fruit of that collaboration.

The internal-combustion engine has undergone constant evolution for centuries, and at this point we’re extracting incremental gains. Plasma ignition could be one of the last significant improvements to be found in the ICE story. Here’s hoping that this ’80s tech, refined for the 21st century’s needs, makes its way onto the streets.

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    If you want to reduce emissions and increase fuel economy, go to smaller engines in smaller cars. Learn to drive stick shift. Drive slower (reduce Interstate speeds back to 55). Live closer to where you work and shop so that you drive less. Nobody needs 750 HP in a car or an 8000 lb pickup truck (unless you use it for work). Look at Europe and the UK to see what they drive. Their gas has been 2-3 times the cost of ours so they HAVE to be economical drivers.

    “Air is one ingrediant that it makes sense to leave alone”. WHY? Air is only 21% oxygen. The remaining 79% nitrogen dilutes the reaction process and creates nitrous oxide pollution. Why not concentrate the air to .. 25% or 30% oxygen using some device like a molecular sieve or bottled O2 supplement. Of course this would not work with a conventional ICE as the burn would be hotter. But we should think out of the box and not dismiss the air component.

    The legendary Smokey Yunick (self-taught mechanical wizard, inventor, NASCAR and Indy car crew chief) experimented with plasma ignition systems. Good to see others taking a look at ideas promoted by him decades ago.

    Any port in a storm, re: the above tech, but if we’re serious about a world in which our i.c. cars can exist, consider that according to the UN and other vetted studies, animals raised for meat and dairy produce more greenhouse gas than all the world’s cars, trucks, buses, trains, planes, ships combined, and every poll of scientists shows them agreeing overpopulation by far our biggest problem, their words, “bigger than climate.”

    Internal combustion cars are a convenient whipping boy.

    Making education, contraceptives available to everyone in the nation and planet, adopting the win-win-win of a plant based, vegan diet would seem our hope; the latter hardly slowing down 78-year-old rodder rocker Jeff Beck, and Lewis Hamilton, world’s leading Formula One driver.

    There is also Pulstar spark plugs that have a unique design to provide similar or near benefits of a full plasma ignition system. I’m running Pulstar spark plugs on my daily driver. The downside is that they are very expensive (~$16 per plug) but I do get 1-2 mpg increase in fuel economy. I’m involved in engine development and unfortunately, even with volume purchasing, it’s an expensive spark plug over a Denso/NGK/Autolite platinum or iridium equivalent and when multiplied by 8, the accountants have heartburn and and us engineers can’t make the business case work. Then to really get the full benefits of the design, you have to lean out the fuel mixture to the get the most efficiency. In the real world, it’s not very likely a customer is going to pay for a 4 times more expensive spark plug and will put in an off the shelf part. Now you are stuck with a control system biased lean, prone to misfire, and possibly out of emissions compliance. Lots of roadblocks to implement this technology. Like the Ionfire system, amplifier and ignition leads present a EMI (Electro Magnetic Interference) that can disrupt the EFI systems, sensor signals, and CAN networking wiring. There are disclaimers on their website for EMI. That is a big no go for todays modern engines. With all of that said, I do like the Pulstar technology and it does allow you to add the technology to any engine and if you have the ability to lean out the fuel mixture or reduce the amount of advance, you can tune in added efficiency.

    There was some comments about melting engine parts but its generally safe for all engines, including LPG and CNG fueled. The only issue is that it does increase the flame front speed which could cause spark knock. Knock will damage the pistons and internal engine parts. The requirement to retard the spark would be dependent on the combustion chamber design however if its a fuel injected engine with knock sensors, it will automatically retard some spark if needed.

    Loved the article. We keep hearing that “this could be the last…”…when reading about cars like (for some examples) the Lexus IS500, Caddy CT5 BW, and C8 Corvette Z06…recent examples that I’ve read about. If new ICE tech/improvements become viable (and there’s market demand), these kinds of cars shouldn’t have to be the last of their kind…

    This concept is fundamentally parallel to what Honda did in 1975 with their CVCC cylinder head. They filled a small pre-chamber with a rich mixture that had the spark plug in it; and filled the main combustion chamber with a very lean mixture. After the rich mixture started burning, an auxiliary valve opened to release the flames into the main chamber to burn the lean mixture. The CVCC system produced exhaust that was cleaner than that of a standard cylinder head / combustion process could do with a catalytic converter. This revolutionized the automotive marked during the oil crisis, giving drivers the option to use the unleaded gas that was required by catalytic converter equipped vehicles, or the less expensive leaded gas; in a time where there were fuel shortages and huge lineups at gas stations for unleaded gas.

    I have a military mindset on EV’s. Would we want military vehicles/equipment of all types powered by battery(s)? I see the threat of EMP (Electro-Magnetic Pulse) being used against us by known potential enemies in any future confrontations. Use of that technology, already “standing by” in space and on earth, could “deactivate” our technology driven forces (to include EV’s) and leave us impotent. Spread that same thinking to our country’s electric grid and….well. Sorry, wandered from engines quite a bit but we need stop the craziness and maximize the efficiency of what we have.

    Back to basics: the Holy Trinity of internal combustion engines is fuel, ignition and compression. More precisely a combustible fuel mixture, compression and adequately timed ignition.

    Taking Anthony Thomas’ comments and some of the others about heat; is the path going forward to use diesel engine transmissions for the lower speed and water injection for the temperature?
    Just wondering

    People like Bob and Dal are jumping on a bandwagon too — the anti-“tree hugger” bandwagon, and exaggerate the environmental problems with EVs. I don’t think plasma ignition stands a chance alongside EV technology. There are two enormous advantages to EVs: 1., they are dead simple, requiring no radiators and antifreeze, no regular oil changes, no fancy automatic transmissions or torque converters (they have a simple transmission system but really require no gears, torque on an electric motor being independent of rpm) and this simplicity eliminates a lot of pollution sources; 2. They produce no pollution whatsoever directly. The pollution Dal mentions associated with mining and disposal is localized and therefore much easier to deal with and much less damaging to the atmosphere than internal combustion cars spread all over the landscape. As for the battery disposal issue, these EV batteries last an amazingly long time, AND even when they become sufficiently degraded to seriously shorten range, they are still useful for solar and wind power storage, so actually disposing of them is way down the road, and recycle technology will probably catch up with that. The nuclear power analogy is a gross exaggeration — they aren’t radioactive or anything and can be recycled in various ways. So we are going EV, like it or not boys, and I wouldn’t hold my breath on plasma ignition even making a dent.

    Great Article but it amazes me to no end how we are trying to save the world with never ending Fixes the Root Cause of almost all of Humanitys Problems needs to be solved but nobody ever even dares to mention it

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