Date:         Sun, 27 Jul 2008 17:51:22 -0700
Reply-To:     Jim Arnott <jrasite@EONI.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Jim Arnott <jrasite@EONI.COM>
Subject:      Re: Induction air flow rates
Comments: To: John Rodgers <inua@CHARTER.NET>
In-Reply-To:  <488D070D.8020406@charter.net>
Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed

It's really just simple math...

Every two revolutions the intake must pass the displacement of the
motor. Calc displacement into cubic feet (1 L = 0.0353146667 cu. ft.,
1.9 L - 0.067097 cu. ft., 2.1 L = 0.074160 cu. ft.), multiply by RPM/
2 That'll tell you how much air has to go through the intake.

If you REALLY want to get into it, pick up a copy of Philip H.
Smith's "The Scientific Design of Exhaust & Intake Systems."

<http://www.bentleypublishers.com/product.htm?code=G309>

 From Bentley's website:

For years, engineers, engine designers, high-performance tuners and
racers have depended on this book to develop maximim potential from
their engines.

Dr. John C. Morrison is one of the foremost authorities on the
analysis of the induction and exhaust processes of high-speed
engines. Together with Philip Smith, he gives a thorough explanation
of the physics that govern the behavior of gases as they pass through
an engine, and the theories and practical research methods used in
designing more efficient induction manifolds and exhaust systems, for
both competition and street use.

Another good reference work is A. Graham Bell's "Four Stroke
Performance Tuning" ISBN  9781844253142

Amazon's got that one:

<http://www.amazon.com/Four-Stroke-Performance-Tuning-3rd-practical/
dp/1844253147/ref=sr_11_1?ie=UTF8&qid=1217206044&sr=11-1>

Both books are indispensable reference volumes. If this is your
"thing" you'll find yourself referring to them again and again.

Jim


On Jul 27, 2008, at 4:38 PM, John Rodgers wrote:

> Volks,
>
> Can any of you really mechanically experienced folks give me some idea
> about induction flow rates - as in air intake flow rates that go to
> the
> engine through the intake manifolds. What would be the volume of air
> going into an engine at say, idle, cruise, top speed? Also the
> speed at
> which that air might be moving? This is an area about which I have no
> knowledge at all and could use such for some planning purposes.
>
> Thanks,
>
> John Rodgers
> 88 GL Driver