IC Engine converted to hybrid air engine

[mfritze]

I was thinking the other day about a possible hybrid conversion vehicle that could store braking energy as compressed air. The setup is like this:

The engine valves are all electric solenoid controlled. When the motor is running on gasoline it run like any other 4-stroke IC engine. There is another valve drilled into the engine head. This valve remains closed during IC engine operation.When the driver brakes, the engine cylinder changes into a compressor. It changes into a two stroke system --drawing air into the cylinder on the down stroke, and compressing the air through the extra valve into a storage tank on the upstroke.

When the car accelerates again, and the pressure in the storage tank is high enough -- the fuel flow is shut off and the pressurized air blasted into the chamber to provide the power stroke.

Please tell me why this won't work --some of the unsurmountable obstacles. I can already imagine that the piston heads might fail at compressing the tank to higher pressures. I don't know much about engines, and some auto engineer has surely thought of this --so why aren't there vehicles today that operate like this?

 

[brewnog]

Yes, it's technically possible. Is it worth it?

Work out the following:

- How much air, at what pressure, could you produce when braking from say 70mph to 10mph?

- How big would a storage tank need to be to safely transport that air under that pressure? How much would it weigh?

- How much power, for what length of time, can you get from expanding the air stored in the tank above?

 

[mfritze]

Well, as suspected, others have thought of this and even have prototypes. I guess the biggest hurtle to implementation is perfecting camless valvetrains.

http://www.treehugger.com/files/2009/02/compressed-air-car-pneumatic-hybrid-system.php

 

[rxfx101]

well, if i recall, Formula 1 and Moto GP have used pneumatic valve trains. I also remember reading about a diesel engine equiped with electromagnetic valve train as well. did a quick search on google for electromagnetic valve train: http://www.google.com/search?q=EMVT...romagnetic+valve+t&pbx=1&fp=ad1bf22abc99c3d7"

and searched pneumatic valve train: http://www.google.com/search?q=pneu...rls=com.microsoft:en-us:IE-SearchBox&ie=&oe="