The mathematics of the 8V vs. 16V problem

[juliemac57 at hotmail.com (Julie Macfarlane)]

Adrian, I am constantly amazed at the intelectual capabilities of this 
group. These are some really smart people...

Excellant description by the way....

Now. Having inflated ego's acroos the list, I go get ready for a meeting 
then to go work on my car....
(Nice to work from home)

Julie Macfarlane
Menlo Park Research & Development
Internet Application Developer
www.menloparkrandd.com
www.montgomeryweb.org
Amsterdam NY





>From: "Adrian" <adrian.culda@sympatico.ca>
>To: <scirocco-l@scirocco.org>
>Subject: RE: The mathematics of the 8V vs. 16V problem
>Date: Mon, 20 Oct 2003 22:56:01 -0700
>
>Wow .. hehehe ..
>I guess this one got everyone busting out pens and pads along with the
>calculators :)
>
>I wonder after thi who will pick on Josh's Injector size :P
>
>Adrian C.
>Project Scirocco R2.oT - "The Turbocharged 16Valves of Fire Breathing
>Fury"
>( 2.0L 16V T66 )
>
>
>-----Original Message-----
>From: scirocco-l-bounces@scirocco.org
>[mailto:scirocco-l-bounces@scirocco.org] On Behalf Of Adrian
>Sent: October 20, 2003 7:12 PM
>To: scirocco-l@scirocco.org
>Subject: RE: The mathematics of the 8V vs. 16V problem
>
>Well here is my non-biased opinion, engines are engines.
>
>Doesn’t really matter how many valves it has (I seen engines having 1,
>2, 3, 4, 5 and even 6 valves for each cylinder!!!), it still performs
>the same task: Takes the gas, burns it and turns that thermo-chemical
>energy and turns it into mechanical energy. But what really matters is
>how much air can flow through it!
>
>As we all know engines are like big air pumps. The more air you can get
>into it the more power it will make. So here is the scientific aspect of
>it...
>
>Air Capacity (in CFM) = ((CID * RPM) ÷ 3456) * VE
>
>Where a 2 valves per cylinder engines, use a VE of .8-.85 at torque peak
>and .7-.75 at power peak and 4 valves per cylinder engines, use a VE of
>.9-.95 at torque peak and .85-.9 at power peak.
>
>To find out Displacement in CID = # Cyls * 0.7854 * bore * bore * stroke
>Or you can convert CC to CID -> CID = CC*061037
>
>If you want to get the results in Lbs/min then -> Lbs/min = CFM * 0.069
>
>The pressure ratio is simply the pressure in compared to the pressure
>out of the turbocharger. The pressure in is usually atmospheric
>pressure, but may be slightly lower if the intake system before the
>turbo is restrictive, the inlet pressure could be higher than
>atmospheric if there is more than 1 turbocharger in series. In that case
>the inlet let pressure will be the outlet pressure of the turbo before
>it.
>
>Injector Sizing
>lbs/hr = ((BSFC / #Cylinders) * HP / Injector Duty Cycle
>
>Brake Specific Fuel Consumption is normally (lb/HP x hr)
>     0.42 BSFC - Race Engine
>     0.47 BSFC - Hi Performance Engine
>     0.52 BSFC - Stock or with Light Modifications Engine
>     0.57 BSFC - Supercharged / Turbo Charged Engine
>
>Injector Flow Rate Conversion
>CC/Min = LBS/HR * 9.71
>LBS/HR = CC/min * 0.103
>
>BTW Most Injector burst pressures are at 125 PSI.
>
>The density of air also varies with its temperature. A cubic foot of
>cold air weighs more than a cubic foot of hot air. A round average for
>airflow vs. hp is 1.5 to 1.6 cubic feet per minute for each hp
>developed.
>
>So as we can see here the more flow the more power the engine will
>produce.
>Sorry for the Long post but someone got to put an end to this.
>Each engine has its advantages and its disadvantages.
>
>If anyone might have any other concerns or questions please email me.
>I used this as a Guide to Build my engine that is about to be completed.
>I more information regarding engine builds and operation.
>
>Thank you, for reading this and taking your time to understand where im
>standing at in this 8V Vs 16V Feud.
>
>Have a Good Night.
>
>Adrian C.
>Project Scirocco R2.oT - "The Turbocharged 16Valves of Fire Breathing
>Fury"
>( 2.0L 16V T66 )
>
>
>-----Original Message-----
>From: scirocco-l-bounces@scirocco.org
>[mailto:scirocco-l-bounces@scirocco.org] On Behalf Of C Boyko
>Sent: October 19, 2003 6:53 AM
>To: scirocco-l@scirocco.org
>Subject: The mathematics of the 8Vvs16V problem
>
>This is a preliminary post resulting from my dyno yesterday, and I
>though
>I'd better post it, since this is such a popular topic for discussion. I
>
>believe this should lay to rest forever the 16V vs 8V discussion...(as
>if)
>
>Hypothesis:
>That doubling the number of valves doubles the horsepower
>
>Method and all that crap: Toss my two cars on the dyno
>
>Observations:
>1987 16V 132.8 hp to the wheels
>1979 8V 66.6 hp to the wheels
>
>Analysis and Conclusions:
>2^3 = 8  (or 6 in certain circles, when used in probability questions)
>2^4 = 16
>
>2^4/2=8, or 16/2=8
>132.8/2= damn close to 66.6
>
>Next Experiment:
>Toss a 20 V on the dyno....WTF, over 300? Well, now we need a formula I
>guess...
>
>
>Seriously, dyno day was fun as usual, and after all that tuning (with
>Klaus
>making the day's low, and Josh C's red beast making the high)
>Since Klaus was supposed to have 76 at the crank according to the
>owner's
>manual (and you lose a bit getting that to the ground) , 66.6 (though a
>bit
>evil sounding) is damn fine for a car with 171000 miles on the engine
>(just
>nicely broken in). I guess there is even a picture with his needle
>buried,
>despite the fact that you could go have lunch while he got to redline.
>(see,
>there is that time component in the hp formula...)
>A few surprises, but most dynoed about where they figured they'd be.
>
>I'll post more about the weekend later, but that should get the flames
>fanned...
>cathy, resident stirrer of the poo
>
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