Valve Spring question

[Rabbit16v@attbi.com (Rabbit16v)]

>
> > Your right, Dan, it does depend on lift but the stiffer springs will
> defend
> > against valve float (I've had it happen with stock springs) and, like I
> > said, seems to make a crisper feel on acceleration.
>
> Well, like I said, if you're using radical cams that have high valve
> accelerations, then you'll need the HD springs, but I don't think the Kent
> 278 falls into that catagory. It's a high performance street cam and is
> unlikely to produce the power peak much higher than 6000 RPM, so no sense
in
> revving higher than 7K which the stock springs can handle.

I agree here but this says nothing more than you said before and neither
approves or disproves what I said in the previous statement.  But I would
think that most who would even think of installing performance cams
frequently go above 6K or even 7K.

> >As long as you have it
> > apart I'd DEFINEATELY install the HD springs especially when you never
> know
> > what the future holds!  You may want to spice it up a little more!  But,
> if
> > you are feeling the financial bind then I'd do what Dan did and stick
with
> > the old stock springs (although new stock springs may be a good
idea??!).
>
> You're putting words in my mouth. I didn't reuse the old springs! The
> springs were new, but they weren't HD. The point to made here is that
Colin
> at TT ported the head. He installed the valve springs and cam and setup
the
> valve tension. So, he clearly felt the stock springs, properly shimmed,
were
> up to the task of handling the valve accelerations produced by the 274
cam.

I didn't "put words into your mouth" I just thought you used the stock
springs that were already there.  It's cool that you used new springs but
you didn't say new so I didn't know.  It's nice that Colin set up your head
for you and I have a lot of respect for Colin and for what he has done for
VW Performance but he is the owner of TT and was the one behind the failed
TT springs dilemma.  I am NOT by any means saying that Colin is not
qualified to do the work he did but what I am saying is that just because
someone is qualified doesn't make everything they do right.  I believe that
Colin believes that stock springs are fine for your setup but at the same
time someone else who may be just as qualified may say differently.  So
saying that Colin built your head to justify your/his decision doesn't mean
that what he decided is necessarily the best possible setup.  Just a thought
and I believe that your head setup may be fine but you always gotta figure
that there could POSSIBLY be a better setup out there.  Now if it works for
you then that's all it really matters but someone else may be looking for a
little more i.e. room for a possible upgrade from a 278 later.

> > Although I don't see where stiffer springs will increase wear and lose
> HP???
> > More on this Dan??
>
> All you have to do is turn the cam in the head by hand. You can feel how
> much harder it is to turn. Harder to turn, more HP required. Stiffer
> springs, more pressure on all the rubbing surfaces. If you're engine is
> properly maintained the additional wear may be minimal, but it will wear
out
> the nose of the cam faster and will wear the bearings faster, particularly
> during startup.

First, you are right about it taking a little more to turn the cam to 'open'
a valve but what happens on the other side of that lobe?  Does it not snap
the cam back to the low spot faster?  So, do we come out even in HP?  No,
but I don't think it robs near as much hp as most people think.  As far as
wear is concerned, I also believe there would be slightly more wear in a
shorter amount of time but, again, minimal if maintained correctly.  The
biggest thing is the gains you will see with the bigger cam(s).  Whenever
you play with boosting your motor (however you do it) there is a downside
whether it is financial or compromising bottom end or higher wear rate there
is ALWAYS a compromise to more power.  It basically comes down to how you
want your car to perform.  I plan on having around 200hp but will only drive
it occasionally so I don't mind the slightly higher wear rate when others
may want to drive their cars everyday with less to normal wear rates.
That's what makes playing with all this stuff fun because there are sooooo
many ways to set them up and finding the perfect setup for yourself is the
task to be tackled, in my opinion.

> Clearly, if you're floating your valves, due to radical cam accelerations
or
>  extremely high revs then HD springs are required. In this case wear will
be
> extreme and Hp will drop in the toilet. A high lift cam will also require
HD
> springs due to coil bind.
> I'm just saying I have a fairly radical 8V, makes 132 whp @ 6200 RPM, revs
> clean to 7000RPM and uses stock valve springs setup by someone who should
> know. HD springs are NOT a power adder if you don't need them!

I don't see how the higher RPMs that are required by you to install the HD
springs will end up extremely wearing your parts and drop your hp in the
toilet?  This doesn't quite seem right since the need of HD springs is to
close the valves quicker so the valves don't float on high rpm monster
motors with monster cams creating high amounts of hp?  As far as not using
HD springs if you don't need them, define need?  Can you not set up a stock
1.8L 16v motor on CIS and rev it to 8K fairly easily?  Before you answer
that, I've done it before and it handles it fine but how long do the stock
springs hold up and why wouldn't you want to assure yourself that the valves
will be closed when that piston comes back around than installing a $150 set
of HD springs?

I am not necessarily arguing with you Dan just pointing out that there is
not ONE WAY of doing anything especially working on our little VWs that have
gobs of possiblities.  A buddy of mine who is into the air-cooled VWs has
always built big motors for his drag car.  He has consistantly been in the
low 12s and, like anyone, has struggled to find the right setup to go
faster.  He decided to go conservative this last year and built a 1914 (or
something like that) and installed a set of heads with stock valves and
stock intake ports (porting done between the intake ports and valves) and it
is the fastest motor he has built to date with 11 sec. runs.  He has ALWAYS
done the welded D ports with big valves etc. etc. but these stock sized
heads with the right porting blew everything he had ever done away.  If you
don't at least try something different you'll never know what could be!

To answer your question, Eric, you can use the stock valves but I depends on
what you plan on doing with your car.  If you plan on going bigger down the
road than you may want to install the HD springs but if 278 is the biggest
you'll ever go then you may want to stick with the stock springs.  Both will
work!

Dave
> Dan
>
> >
> > Dave
> > ----- Original Message -----
> > From: "Dan Bubb" <jdbubb@ix.netcom.com>
> > To: <scirocco81@vwmail.net>; <scirocco-l@scirocco.org>
> > Sent: Sunday, February 23, 2003 7:53 AM
> > Subject: Re: Valve Spring question
> >
> >
> > > Eric:
> > > I think the need for the HD springs is driven by valve lift unless
your
> > > talking about a real high duration cam with radical valve
accelerations
> > > (which I don't think the Kent 278 is. Kent durations tend to be
measured
> > at
> > > lower lifts, so their durations are generally higher for a comparable
> > cam.).
> > > I'm running a Schrick 274 with 11.3 mm lift using stock valve springs.
> > > Controls the valves to 7000RPM. Colin at TT setup the cam and valve
> > springs
> > > initially and shimmed up the springs as much as reasonable without
coil
> > > bind. I looked, but couldn't find a Kent 278, so I don't know the lift
> > > I don't know the actual limit, but I suspect anything over 11.3 lift
is
> > > going to need the HD springs.
> > > No sense running a stiffer spring than you need. It's just wasting
wear
> > and
> > > tear and lost HP.
> > > Dan
> > >
> > > ----- Original Message -----
> > > From: Eric S <scirocco81@vwmail.net>
> > > To: <scirocco-l@scirocco.org>
> > > Sent: Saturday, February 22, 2003 3:17 PM
> > > Subject: Valve Spring question
> > >
> > >
> > > >
> > > > Hey all...planning on installing a Kent 278 cam on my 83
Rocco....can
> > the
> > > stock valve springs handle this cam?  Or do I need to upgrade to HD
> > springs?
> > > If so, what brands are reccomended, and who has the best prices?
> > > >
> > > > --
> > > > Eric
> > > > Northglenn, CO
> > > >
> > > > 81 Scirocco S (*TDI* swap and complete restoration in holding
pattern)
> > > > 81 Rabbit Truck LX Diesel (Waiting for BAE Turbo Install)
> > > > 83 Scirocco Wolfsburg
> > > > 91 Cabriolet (2.0 Crossflow 8v swap and mechanical rebuild in
> progress)
> > > >
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