MTFCA Forum

I was impressed by the 1906 Compound car at Harrah's many years ago. It's engine "operated one of its cylinders from the force produced by exhaust gases from the two explosive cylinders. The result was a reduction in noise and saving power". That amazed and amused me. When I found this video of one running, I thought I should share it here.
https://www.bing.com/videos/search?q=19 ... M%3DHDRSC4 A more elaborate explanation "The outer two, 4-cycle high-pressure cylinders "explode alternately" and exhaust into the larger, 2-cycle low-pressure cylinder rather than into the atmosphere. Here the exhaust gas expands further and drives the piston down before exiting through a small muffler. This compounding of the exhaust gas allowed for more complete combustion that allegedly resulted in a cleaner, odorless and very quiet final exhaust. It also increased fuel economy."
"Of the 300 Compounds produced, this Light Touring Car is the only one known to survive. It is also one of the few cars in the museum whose provenance can be traced all the way back to its original owner, John Unser, chief engineer at the E.H.V. Company. After Unser sold the car in 1934, it passed through a number of owners, including Henry Austin Clark (Long Island Automotive Museum), Harrah's Automobile Collection, General William Lyon, Bill and Doug Magee, and Carl Schmitt. While at Harrah's, it received one of their famed Gold Star restorations."

Interesting.
I wonder if the second cylinders were prone to more carbon build up filth to the point of higher maintenance of those cylinders.

A three cylinder engine - the middle cylinder runs off the exhaust from the other two. Amazing. Were we informed in 1963 or sentient ???

Proves that EGR is not all that new in the emissions reduction world.

An interesting idea. Compounding was highly developed in steam engines. The problem with compounding a gasoline engine is not that there isn't a lot of energy in the exhaust stream, but that recovering it via expansion inhibits the function of the cylinders supplying the exhaust stream. It would be very interesting to see an accurate "BTU budget" for this engine.

And a bit more detail:

Double-acting pistons?

This idea is not dead by any stretch of the imagination see Bruce Crower's idea @
autoweek.com/a2063201/inside-bruce-crowers-six-stroke-engine/
Craig.

Where would we be without those freethinkers willing to pursue their ideas.
Thanks for the post.
Rich

Most interesting thing I’ve heard about all week

A supercharged, direct injection gasoline engine might be able to take advantage of the compounding principle.
Run the combustion cylinders well above atmospheric pressure, and expand the very hot, high pressure exhaust in expansion cylinders with ceramic pistons. Mechanical complexity would be an issue. Two cycle combustion cylinders might be advantageous, if you could keep them cool. Perhaps double acting 2 cycle combustion cylinders with one side being combustion and the other being devoted to fuel injection/vaporizing/supercharging would offest the cooling issue. The idea might be best applied to a stationary installation running at a governed speed, like a power plant, where weight, complexity, and flexibility would be less critical.

Actually, a typical turbocharged engine applies the same fundamental principle by extracting energy from the exhaust stream thrrough a turbine and appying the recovered energy to running a high volume compressor to supercharge the engine's intake tract, thus avoiding most of the issues with high heat, mechanical complexity, lubrication, and weight and ultimately recycling a good deal of the waste energy in the exhaust.

Then there's the jet engines used in modern aircraft, which are gas turbines running turbine air compressors in order to burn huge amounts of fuel and generate high volume, high pressure exhaust streams, which streams are applied directly to propelling the aircraft.

There is one (the only one left?) at the Fountainhead Auto Museum in Fairbanks, Alaska.

https://www.fountainheadmuseum.com/foun ... f-our.html