Date:         Wed, 27 Jul 2011 21:34:37 -0400
Reply-To:     Mike <mbucchino@CHARTER.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Mike <mbucchino@CHARTER.NET>
Subject:      Re: dumb fuel injection question
Comments: To: Mike S <mikes@FLATSURFACE.COM>
In-Reply-To:  <20110727230354.BFC25A007C@locke.alientech.net>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
              reply-type=response

This is why there's very little time actual "waiting" for the intake valve
to open.
Effectively almost none at all.  'Closed' is a relative term; it behaves
more like a superfast pulse.
BTW, the fuel droplet is not starting at rest; it's under both a high
pressure and a high rate of flow.
So, it has a running start; that way it sprays in a nice conical pattern and
atomizes to mix well with the air for optimum combustion and complete
burning.
Yes, the newer sequential timed injection systems are both more fuel
efficient and have lower emissions, and as a bonus, higher power output!

Mike B.

-----Original Message-----
From: Mike S
Sent: Wednesday, July 27, 2011 7:03 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: dumb fuel injection question

At 05:32 PM 7/27/2011, Rocket J Squirrel wrote...
>Three out of four fuel injections get squirted at a closed intake
>valve.
>What possible difference does the injector pattern make then? And what
>does the fuel do when waiting around for the valve to open? Puddle?

At 2040 RPM, each intake valve opens 17 times per second.  In the 59 ms
between valve openings, a droplet starting at rest would only drop 0.7
inches. Of course, there's a lot of turbulence in there, so things get
mixed up. There's simply not enough time for the fuel to puddle. It
just hangs around as a mist, waiting to get sucked into the cylinder.