16V Cam Sets & Idle Characteristics

[fahrvegnugen at cox.net (David Utley)]

> 
> From: "Rick Kellner" <rfkellner@snet.net>
> Date: 2004/12/21 Tue AM 07:52:03 EST
> To: <scirocco-l@scirocco.org>
> Subject: 16V Cam Sets & Idle Characteristics
> 
> The more aggressive cam sets for the 16V list rough idle, on fuel
> injected cars, as a side effect.  Other than switching to carbs or MS
> type management does anyone know of a solution to the idle problem?  Is
> it vacuum related or is the fuel current signal causing the poor idle?
> Does a larger, i.e. 50 mm intake help or hurt the problem?  Lightened
> flywheels help/hurt the problem?
> Finally, anyone with different cam sets want to comment on how bad the
> idle is?  The worst idling car I have ever driven is my brother's built
> to the hill 69 Chevelle 454. 
> Rick.

As I understand it, it is vacuum related.  The air metering plate works because it is moved by the air on its way to the engine.  The agressive cams can cause a pulse of air that works its' way back to the metering plate.  This is why the idle is affected so quickly.  I would assume that 16Vs are worse about this than 8Vs for the fact that they move more air too.

I would think that EFI is the only way to completely cure this...

HTH

David

Nothing can bring you peace but yourself. 
--Ralph Waldo Emerson