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[Scirocco-l] Re: Was: Stretch bolts vs. studs... Valve springs



Anyone else still getting double posts?
Anyone else still getting double posts?

Larry   sandiego16V
Larry   sandiego16V



----- Original Message -----
From: Dan Bubb <jdbubb@ix.netcom.com>
To: rocco16v <rocco16v@netzero.net>
Cc: <scirocco-l@scirocco.org>; <Cmr446@cs.com>
Sent: Thursday, January 03, 2002 5:05 AM
Subject: Re: [Scirocco-l] Re: Was: Stretch bolts vs. studs... Valve springs


>
>
> rocco16v wrote:
> >
> > Steve-
> >   1. If you are going to run a STOCK exhaust cam on the intake (???),
then
> > run STOCK springs.
>
> I think it's fairly commonly known that the 16V exhaust cam is quite a
> bit more aggressive than the intake cam (20 deg more duration and .050"
> more lift) and if you're up for the machining required to convert it for
> intake use it will increase both the max power of the engine and the RPM
> at which it happens.
> Personally, I'm not sure why the stock springs properly shimmed wouldn't
> be adequate for street use. They'll handle at least .423 lift and they
> are the same springs that can control a 40mm intake at 7000 RPM in an
> 8V! Since the 16V valves are smaller and lighter they should have a
> higher valve float speed UNLESS the 16V cams have higher accelerations.
> I've never seen camshaft acceleration fiqures which is one of the
> primary factors to determine valve spring rate, but I'd be willing to
> bet they'd be comparable between the 8V and 16V.
>
> > 2. If you accidentally over-rev the engine, then heavier springs may
save
> > your bacon.  But, INTENTIONALLY over-revving is counterproductive to
going
> > fast.  Each engine has a point at which more revs equal LESS horsepower.
> > For a stock 16V Scirocco, that point is 5800 rpm.
>
> With an exhaust cam machined for intake use the max power speed will
> increase. It will probably be a waste of time to rev to 8000 RPM unless
> the engine is pretty radical, but revving into the 7's will probably be
> required for max acceleration with the engine Steve appears to be
> building.
> Dan
>

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