saw this on motoring TV, this could be a game changer. Not sure how to post the video of how it works, maybe one of you techies can?
Anyone recall a guy running a top fuel car probably back in the 80’s using rotary valves? Looked like a cool concept that got rid of the cam, pushrods, valve springs and valves! Just relied on a pressurized horizontal tube that had openings for intake and exhaust.
Take a look at the Achates engine design ... about half the displacement of current engines puts out almost the equivalent high power traditional ICE (internal combustion engine). The design is extraordinarly "power dense" (the power stroke drives two pistons simultaneously = torquey son of a gun) and the valvetrain is far simpler with far fewer moving parts (less friction and parasitic power loss). A pair of opposed pistons share the same single combustion chamber ... the power stroke pushes on the two literal opposing piston tops. Think of a boxer type engine with horizontally opposed pistons, but there are two crankshafts at the outer ends where the heads and valvetrain are on a traditional boxer design so that the piston tops move to the enter of the engine where the common intake and exhaust are located. The company has a new contract with the Pentagon and Cummins for development of a 1000 hp engine 5 or 6 liter or so turbocharged engine estimated to put out some serious torque. The Calif. Air Resources Board (C.A.R.B. ... the people who want to ban your musclecar from being driven on the street) recently contracted with Achates Power for a build of an ultra low emission engine for a class A semi ... it is a 10 liter 3 cylinder engine (remember, that's 6 pistons) and is is 15% lower emissions, 450hp and 1750 lb./ft. of torque. Here's one catch, though: each cylinder has two opposed pistons which equates to twice the stroke-to-bore ratio of a traditional ppiston engine and it is effectively a two stroke in that the combustion cycle (power stroke) occurs every time the top of pistons in each cylinder are at TDC. So, a 3 clyinder Achates engine has 6 pistons because each combustion chamber drives two pistons in the opposite direction. The tops of the opposing pistons have unusual shapes which work together to help "swirl" the air to aid in optimization atomization of the fuel/air mixture for maximum power with as little fuel as possible. Pay especially close attention to the displacement for comparisons because each cylinder has two pistons. The engine design can be made for gasoline or diesel and also in a gasoline compression ignition system. Not "dual fuel", rather some minor changes to the engine and fuel system are required for each version - gas or diesel. For packaging sake, the engine can be flat like a boxer or vertical or diagnal like an I-6 or Slant 6. A look at how the Achates engine design works: https://youtu.be/JoQkTIfAB2U An 3 cylinder 2.7 liter Achates engine in a test F-150, 37 mpg/270hp/480 lb./ft. torque & 50% efficiency gain: * a diesel version of the same gas engine above would get 42 mpg combine CAFE rating. This video is probably the best for technical explanations and facts/figures: https://youtu.be/UF5j1DvC954
There was also a guy making V-twins with rotory valve heads back in the late 90s/early 2000s for the custom chopper market that was so big then. Can't remember the name and been Googling it, but I read an article on it in Cycle World back then. Pretty neat concept. Here's a pic of rotary valves for the guys that don't know what we're talking about: EDIT: found the bike engine. It was Coates engineering make them, called CSRV heads:
German mediam sized airplanes in WW2 flew with these engines. Of course, the modern technology is what makes them low pollution emitters now (simple open ports or Reed valves on older engines do not offer modern intake and exhaust gas control) and a host of other improvements.
