[bwilson4web]

Hi,

I finally got tired of not finding a good web page describing how a modern Atkinson engine works so I made my own.

Bob Wilson

[jdenenberg]

Bob,

A nice description. I noted the following:

"This cycle repeats for each cylinder, passing some of the charge from the first half of a compression stroke to another cylinder during the first half of the intake stroke of a second cylinder until the delayed-closing of the donor cylinder. But since the intake valve closing of the donor cylinder is variable, this also controls the amount of fuel-air charge in the donor cylinder. This provides another throttle plate function without the throttle plate restriction the source of 'pumping losses.' In fact, the next generation of variable valves eliminates the need for a throttle plate. "

I would go further. If we now have a binary valve (always open or closed, no partial opening) we have may have significantly reduced pumping losses. This is analogous to replacing a linear voltage regulator with a modern pulse width modulator in a power supply to get better efficiency (85-90% is typical in DC-DC converters and AC inverters).

JeffD