SC -- dumb question

[Gregory A. Parmer]

On Thu, 20 Mar 1997, Tom Cloud wrote:
> it's been a long time since I've asked a dumb question
> on this list (how do I know .... it's been a long time
> since I've said _anything_ on this list  ;-)

Same here. What's this...only a week late? :)

> got to thinking:  if a nnn CID engine always pumps nnn CI
> of air/fuel per two revs, and the limiting factor that
> controls it is the 'density' (i.e. vacuum) of the air
> (i.e. throttle position), how does that work with turbo/
> super charging??  is the plenum always pressurized, or
> is there still the vacuum at low rpm's ???

I didn't notice a response to the first part of your
note, so...

An "nnn CID engine" always *attempts* to pump nnn CI
of A/F per 2 revs. Remember that the VE is a measure
of what percentage of nnn that actually flows thru.

Measuring the 'density' is almost always a relative
measurement since it'll be based on where and when
the measurement is taken (ie, at the base of the valve
upon opening or closing, at the piston at BDC or TDC).

Any way you look at it, a pump (TC or SC) will still
help you get more charge into the cylinder where it
can do some good.

$0.02
-greg