1980's 2.5L 250HP, 250TQ, 51 MPG Hot Vapor Engine

[Steve85]

It's a bit of a read but interesting if your into engine technology. Especially that developed by a legendary hot rodder and then right before going mainstream, squashed by GM.

http://www.hotrod.com/techarticles/engin...index.html

Cliffs:

Smokey developed a 2.5L (151ci) Iron Duke four-cylinder Fiero engine that met all '80s emissions standards (with a carburetor and no computer), made 250 hp and 250 lb-ft of torque (compared with about 90 hp and 125 lb-ft stock), went 0 to 60 mph in 6.5 seconds (stock was 12 to 13 seconds), and managed to get as high as 51 mpg on the highway running 93-octane pump unleaded premium gas (the stocker got about 35 mpg on 87-octane)

To completely vaporize the fuel, Smokey used heat from the water in the engine's cooling system plus exhaust heat to progressively warm the system's induction flow to the required temperature. There was a heat exchanger under the carburetor that used hot engine coolant exiting the motor to warm the mixture to around 200 degrees. The air/fuel charge then flowed through a second-stage generator, an exhaust-driven turbine wrapped with exhaust-gas ducting.

The '80s vapor motor's A/F ratio was well over 20:1.

It was the "not invented here syndrome" rearing its ugly head again. How could a couple of gearhead hot rodders know more than all of Detroit's best engineering talent? By this time, Detroit was committed to the computer, fuel injection, and the catalytic converter. Traditional theory was to get rid of or manage heat; Smokey was channeling heat for improved performance, the exact opposite of conventional engineering science.

For example, a typical small-block Chevy runs reliably at a 1,750-degree F stabilized exhaust temperature. At 2,250 degrees, you're definitely in trouble from engine-destroying detonation. But Ralph says "if you can take it to 2,600 degrees F, you can control the burn rate of the hydrogen molecule in the fuel, the major radical in the gas that's causing detonation.

paraphrasing: How to get from 2250 to 2600 without melting the engine is the big unknown. It's believed that the cam design was the big secret to doing it.

"The time will come when engines will be fully accepted as a heat pump."

A few companies are experimenting again with this. If the cam design was the key to getting over the temp hump, then direct injection, variable cam timing, and precise engine controls could yield some incredible HP-MPG combos.

[balactm]

that's really awesome. I love stuff like that. Like the ronn motor company scorpion. It has an on-board electrolysis machine that allows 42 mpg with a 4.8 0-60 time. SWEET

[BLINGMW]

cool article, glad you posted it. That is, BY FAR, the most attention the iron duke will ever get. 8)

Can you imagine tuning a carb to do this?! :vomit:

Very neat and amazing where it came from, but the idea's not shocking after you read it. Just like any turbo car, sure, if you could run it that hot for extended periods of time, you could have both awesome fuel economy and power. Build the whole engine out of ceramic (no problem, where's my potting wheel?) and you're set!