The mathematics of the 8Vvs16V problem

[jason at scirocco.org (Jason)]

At 07:41 AM 10/20/2003, Dan Bubb wrote:

>Just don't go thinking that because you have a 16V or even a 2.0 16V you're
>going to kick sand in the face of every 8V you run across.

Yeah yeah yeah, and I'm sure there are lots of girls out there who say 
"Size doesn't matter..."  And just like in the 8V vs 16V debate, there are 
numerous websites devoted to the micropenis -- but the fact of the matter 
is, their admirers are the exception rather than the rule.

>  The 16V guys also need to make some effort beyond chanting:
>"16V,16V,16V........"

lol - okay so providing all the quotes from the auto industry blasting the 
8V and unanimously declaring the 16V better in every way without any 
penalty wasn't enough, how about this:  Show me one dyno plot from one 
normally aspirated 8V motor that has as powerful and broad of a torque 
curve as a 16V motor.  Yes, any engine can be tuned to make a lot of power 
at peak, but I've not seen a single 8V that can do what a 16V can from idle 
to 7000rpm.

Case in point, please see the following curve: 
http://www.scirocco16v.org/dyno/16V.jpg
This is a dyno plot from one of our veteran list members.  It's a 2.0 16V 
with a slightly P+P and shaved head; Schrick 260/276 cams, and an 
exhaust.  That's a relatively stock motor in my book -- the entire bottom 
end is completely stock.

You'll see that not only does it peak out at 144whp and almost 133 lb-ft of 
torque, but the torque curve itself is tremendously broad and beefy:  This 
engine puts more than 120 lb-ft of torque to the wheels from 3000 until 
6250rpm.  That is a simply awesome number from a 2-liter engine... and 
flies directly in the face of any complaints of the 16V being a dog down 
low.   And further, this particular motor puts down about the same torque 
at 2000rpm that the 1.8 16V does at its peak -- just under 100 to the 
wheels -- which is, as we know, more torque than any VW 8V motor (including 
the ABA) did from the factory.  So there's monumental high-rpm power (VR6 
territory) with low rev torque besting all other VW 4-cylinders.  You just 
can't do that in an 8V VW motor.

>Hoping I'm the first to take the bait!

Okay, so now that I've taken yours:  My joke(s) above aren't meant to 
offend anyone.  They're for laughs.  If you don't find them funny, I'll try 
harder next time, but save your criticism please.

And to be completely honest, my "summary" of the 8V vs 16V war is 
follows:  There should be no question in anyone's mind at this point that 
in general as well as in the case of Volkswagen engines in particular, 
multivalve engines are far better all-around performers.  If that weren't 
the case, you'd see all kinds of new 2-valve-per-cylinder engines being 
introduced from the world's great engine builders - BMW, Ferrari, Honda 
etc...  Aside from inexcusable "updates" from the world's worst engine 
builders (our pathetic US car makers) based on 1960s technology, we see no 
new 2-valve motors... *especially* in any small 4-cylinder application with 
"sporty" aspirations.

The VW 8V engines are not without merits.  Their longevity is world 
class.  They're relatively smooth and economical.  They have fantastic 
throttle response everywhere in the rev range - better than the 1.8 16V 
certainly - and are eager to please.  Their torque curve is ideally suited 
for around-town driving -- the torque is concentrated down low where you 
need it most.  They breathe decently well at high revs, but their most 
happy place is under 4000rpm.  They are fantastic engines for daily use - 
which is where they've found themselves these days.  They are, however, at 
a distinct disadvantage at high revs, which makes them less suited for 
high-performance applications.  The high-performance versions of VW cars 
now all use 4- or 5-valve per cylinder engines... and for a reason.

Sure you can have a powerful 2-valve per cylinder engine.  An 8-Liter 16V 
V8 Viper engine is powerful.  And my 2 favorite engines of all time are 
both 2-valve per cylinder powerplants:  VW's VR6 and BMW's M20 
2.5-liter.  Both of these inline 6s, however, wear very aggressive cams and 
are tuned for high-rpm power...  and they scream.  But admittedly they've 
both been replaced by 24-valve variants.  And as much as I mourn my old 
engines, and as much as they both have a few benefits over the new ones, 
the 24V motors are more powerful everywhere in the rev range.  And so I 
keep my VR6 and 325i -- but understand their limitations.

And you 8V boys should, too.

:)
Jason