Search results for query: *

But you see. Pumping losses are about 4% at what throttle? At full throttle I can see a 4% loss because it doesn't work against much as there is no vacuum or anything. At part-throttle you have a big vacuum, and while there might be a spring back it's not near as much pull as when the valve was...

Most testing i've done to date involved single cylinder OHV/OHC engines. We tested alot at 50% throttle because that's where most poeple spend time accelerating at in most cars before they let off to 5-25% depending on speed. We drove the engine by electric motor to measure power required to...

Because it takes less power to pump the air twice than it does to work against the vacuum. Especially the larger the engines displacement is.

I understand that there will be a little bit of a vacuum. I guess i was too vauge in either my description and title or i had just assumed that everyone would understand that the only vacuum that won't be there is the one created in the intake manifold for engine throttling. I guess the closest...

The throttle is controlled by closing the intake valve later and later. Like idle might be closing the intake valve 45 degrees BTDC on the compression stroke(never been done so i just have to throw a number out there. So instead of working against a strong vacuum at idle it pulls a full charge...

Does anybody here know if someone is working on an engine that has no manifold vacuum? I have a few things i've gome up with that involve an IC engine with no manifold or chamber vacuum at part throttle. The engine basicly purges the charge from the cylinder again into the intake...