The theory is the reason why engines with bad headgaskets have cleaner pistons is because the water/radiator fluid is getting into the cylinder and breaking carbon up. But i read that it takes hundreds of miles for that to happen, not just spraying some water into the intake.
And I would assume chunks of carbon might clog the cat also.

 

Not to make an enemies...but no. Lead (tetraethyl lead, to be specific) was added to gasoline beginning in the 20s and was championed by none other than GM because it provided superior knock resistance DESPITE the poor quality gasoline available at the time. Hot rodders LOVE to rant about the "low quality" fuel today, but the reality is that hydrocarbon purity has never been higher. The "high octane" gas of the muscle car golden age was cheap swill hopped up with "looney gas" brain poison.
https://www.google.com/amp/s/www.wir...d-history/amp/
Leaded gas began to be phased out in the early 70s in the U.S. because of its harm to catalysts, not for its detrimental effects on human development.

Regarding the hot air engine, the resources are available to repeat the experiment:
https://www.google.com/amp/s/www.hot...ir-engine/amp/
All engines suffer from inefficiencies resulting from heat management. Though the exact figure depends on the specific engine in question, most estimates are between 75-90% energy loss through heat and friction. Master those and you boost power and efficiency. Modern common rail diesel engines use direct injection and high pressure injectors to achieve more than 30,000 PSI. The atomization of the fuel is as complete as any engine known to man up to this point (perhaps barring LNG/propane, of course!). With ceramic piston coatings, turbocharging, water meth, high-purity fuels, and other technological advances it is difficult to see how the same excellent mileage couldn't be achieved today. Perhaps if cars and there driver's hadn't bloated so substantially in the last four decades we would have our answer.

 

Hotdogstand, I read your linked article, which supports what I wrote.
Although GM and Standard Oil had formed a joint company to manufacture leaded gasoline – the Ethyl Gasoline Corporation – its research had focused solely on improving the TEL formulas. The companies disliked and frankly avoided the lead issue. They’d deliberately left the word out of their new company name to avoid its negative image.

You wrote, Leaded gas began to be phased out in the early 70s in the U.S. because of its harm to catalysts, not for its detrimental effects on human development., but the article says In 1926, citing evidence from the TEL report, the federal government revoked all bans on production and sale of leaded gasoline. The reaction of industry was jubilant; one Standard Oil spokesman likened the compound to a “gift of God,” so great was its potential to improve automobile performance.
The resulting comparison of street dirt in 1924 and 1934 found a 50 percent increase in lead levels – a warning, an indicator of damage to come, if anyone had been paying attention.
It was some fifty years later – in 1986 – that the United States formally banned lead as a gasoline additive. By that time, according to some estimates, so much lead had been deposited into soils, streets, building surfaces, that an estimated 68 million children would register toxic levels of lead absorption and some 5,000 American adults would die annually of lead-induced heart disease.

So TEL was banned (eventually, 50 years later) because of health effects. And as always, it's ALWAYS about the money - even back in the 1920s.
Face it, auto makers build cars. Cars run on gasoline. Why wouldn't they want to get into the gasoline business? And a 200 mpg carburetor would certainly threaten their profits, even back then with gas costing only 10 cents/gallon.


But this is not what this post is about. So sorry to the OP for hijacking.
Back to our regularly scheduled program.

 

The federal government banned TEL in the 80s, as you state, but it was already phased out in most of the country because it destroyed catalytic converters. Note the 10+ years between catalysts becoming standard equipment and the (now worthless) ban of leaded gas. If no one was selling it, who did it hurt to ban it? Follow the money indeed...
Never trust a corporation- they owe all they are to the customer, but they seek the approval of the board, and the board seeks profits above all else.

My point was that lead was a CHEAP way to make cars run better, rather than producing higher quality (and higher octane) fuels or make any significant increases in engine technology. Heck, the variable cam, direct injection, computer-controlled, 200 mph death machines we all drive now are gifts from the EPA's CAFE mandates. Do you think GM (or anyone else) would have spent the money R&D if the government hadn't forced their hand? The free market is a wonderful thing, but history has shown that the consumer prefers cheap, and new technology is anything but.

 

You are wrong. Many years ago this was a common practice. I have sprayed a garden hose set to mist directly into many carb intakes while reving engine with the linkage. I was amazed at how much water an old V8 could ingest . A steady spray no problem, just keep the revs up to about 2000. There would be clouds of black crap blowing out of the exhaust. I haven't done it in years, could be bad for catalytic converters

 

The black cloud is misfires fool.

 

Have you ever actually sprayed water into a running engine? I have, different engines, many times. I was told about it by an old aircraft mechanic in the early seventies. It worked and did no harm to the engine, however cars did not have catalytic converters then, the removed carbon may block or damage a converter. Here is another example, a leaky head gasket can let engine coolant (mostly water) enter a cylinders combustion chamber, these engines will often run fine like this for some time until the condition is noticed.( low coolant level, wet exhaust, high oil level- coolant in the oil) Have you ever encountered this or dismantled such an engine? I have. The wet combustion chamber is the cleanest one in the engine, very little or no carbon remaining. Water injection is nothing new, it has been used for years for various reasons. Google " water injection".
After you have read and learned more do this, Google "fool", now go look in the mirror.
Hey I'm kidding you, I'm joking. We should not be trash talking here, lets promote knowledge.

 

Yes, misting water into the carb does clean the engine. Back during World War II people connected water bottles to their vacuum connection on their carberator so they could lean the fuel consumption way down. Extra fuel is drawn through the carberaor to add engine cooling and is waisted out the tail pipe. The mist from the water bottle replaced the waisted fuel used for cooling and the water vapor did clean rthe inside of the engine and exhaust system. The water bottle had 2 metal tubes attached to the lid, 1 was long and shaped like a candy cane, it extended down through the center of the lid with the tip almost touching the bottom. Nothing was attached to that tube, The second tube is very short and only extends down to the inside bottom of the lid. That short tube was connected to the vacuum which caused the water to boil creating a mist inside the jar. (Note, you do not want to allow any water droplets or raw water to enter the engine while it is running.) By the way, I was an aircraft mechanic in the Military for 20 years..

 

These pictures shows the type of device that was used back during the war to aid in fuel consumtion. The short tube was connected to the carberator causing a vacuum inside the bottle which caused air to come through the large tube causing the water to boil making a water vapor to be sucked into the carborator through the short tube. With this device you did not have to rev your engine, you just let it run normal as you drove