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1.8L head on 2.0L block
Yup I know, I just want to bug 16V peoples ;)
Marc
'83 Scirocco
'88 Scirocco Slegato
> -----Message d'origine-----
> De : Euroroc II [mailto:flaatr@yahoo.com]
> Envoy? : 28 juin, 2003 14:25
> ? : Marc Scirocco Qu?bec; scirocco-l@scirocco.org
> Objet : RE: 1.8L head on 2.0L block
>
>
> I think this argument is for the 16V heads... it has been
> argued since the
> beginning of time about the differences and benefits of the
> 1.8L 16V head
> vs. the 2.0 16V head...
>
> I don' t think you 8V'ers have this silly problem, lucky.
>
> -Raffi
>
>
> At 12:58 PM 6/28/2003 -0400, Marc Scirocco Qu?bec wrote:
> >I have an 8V Audi 2.0 head. It is already ported a bit.
> >
> >Cheers.
> >
> >Marc
> >'83 Scirocco
> >'88 Scirocco Slegato
> >
> > > -----Message d'origine-----
> > > De : scirocco-l-bounces@scirocco.org
> > > [mailto:scirocco-l-bounces@scirocco.org]De la part de ATS
> - Patrick
> > > Bureau
> > > Envoy? : 28 juin, 2003 12:51
> > > ? : Dave Ewing; scirocco-l@scirocco.org
> > > Objet : RE: 1.8L head on 2.0L block
> > >
> > >
> > > well I have a stock 1.8L on a 2L block , but its 8v, npw
> > > anyone has a stock
> > > 2L engine 8v on hand and we can compare..
> > > I need to get a dyno run though.. :)
> > >
> > > ATS - Patrick Bureau - txrocco@sbcglobal.net
> > > Http://www.longcoeur.com/scirocco/
> > > ============================================
> > > '85 2.0L Prowler Orange Kamei X1 Rocco
> > > '85 1.8L Titian Red Rocco (daily driver)
> > > '98 4.0L Jeep Cherokee
> > > '91 7.3L F250 diesel Super cab,8 Ft box.
> > >
> > >
> > >
> > > =>-----Original Message-----
> > > =>From: scirocco-l-bounces@scirocco.org
> > > =>[mailto:scirocco-l-bounces@scirocco.org]On Behalf Of Dave Ewing
> > > =>Sent: Saturday, June 28, 2003 11:47 AM
> > > =>To: scirocco-l@scirocco.org
> > > =>Subject: Re: 1.8L head on 2.0L block
> > > =>
> > > =>
> > > =>But who in the world has a stock 1.8L head on a stock 2.0L block
> > > =>and a stock
> > > =>2.0L head on a stock 2.0L block?? Anyone??
> > > =>
> > > =>Dave
> > > =>----- Original Message -----
> > > =>From: "Dan Bubb" <jdbubb@ix.netcom.com>
> > > =>To: <scirocco-l@scirocco.org>
> > > =>Sent: Saturday, June 28, 2003 6:44 AM
> > > =>Subject: Re: 1.8L head on 2.0L block
> > > =>
> > > =>
> > > =>> I've been thinking about this alittle more. We all know
> > > what that means!
> > > =>> I was thinking about the conditions in the cylinder during the
> > > =>intake and
> > > =>> exhaust and how that is related to flow.
> > > =>> The power an engine produces is largely related to
> how much air
> > > =>it burns.
> > > =>> >From that is subtracted the various inefficiencies.
> > > Pumping losses,
> > > =>> inefficient combustion, heat losses.....
> > > =>> If your intake is restrictive then you get less air and
> > > proportionally
> > > =>less
> > > =>> power. So, 7% less air pretty much starts you at 7% less
> > > power. The
> > > =>probable
> > > =>> most important secondary effect on the intake side is intake
> > > =>velocity. The
> > > =>> same amount of air at a lower velocity will generally
> > > produce less
> > > =>> turbulence in the combustion chamber, slower burn and
> less power.
> > > =>> Flow thru the exhaust is not a power producer. It's a
> > > power loss. The
> > > =>> exhaust valve starts to open well before the piston
> > > reaches BDC on the
> > > =>power
> > > =>> stroke while the cylinder pressure is still very high.
> > > So, alot of the
> > > =>> exhaust gets a huge boost out the port due to the really
> > > high pressures
> > > =>> (compared to intake pressures or the average pressure level in
> > > =>the exhaust
> > > =>> system).
> > > =>> Once this slug of exhaust is out the piston still has to do
> > > =>work to force
> > > =>> the rest of the exhaust into the pipe, but the general
> > > exhaust system
> > > =>> pressure isn't that high (on the order of a couple
> psi even for an
> > > =>> inefficient system) so the power lost pushing the remaining
> > > =>exhaust out is
> > > =>> not huge. Now, obviously, the lower the exhaust port flow
> > > the more power
> > > =>is
> > > =>> lost pushing the exhaust out and you also will get more
> > > charge dilution
> > > =>with
> > > =>> high exhaust back pressures that will have an effect on
> > > the amount of
> > > =>power
> > > =>> produced by the incoming charge.
> > > =>> The main point is; power is directly related to
> intake flow, it is
> > > =>> secondarily related to exhaust flow. i.e. the cylinder
> > > =>pressures producing
> > > =>> power (in the area of 1000 psi) are directly related to
> > > intake flow and
> > > =>the
> > > =>> cylinder pressures loosing power (<10psi) are directly related
> > > =>to exhaust
> > > =>> flow.
> > > =>> Having said all that it seems like intake flow is the most
> > > =>important (and
> > > =>as
> > > =>> Dave points out, it's not just the port. it's the
> entire intake
> > > =>tract) and
> > > =>> exhaust flow of secondary, although not
> insignificant, importance.
> > > =>> On the topic of intake velocity; I'm not sure the 2.0 head
> > > =>necessarily has
> > > =>> better velocity despite the lower flow. I haven't seen an
> > > =>actual 2.0 head,
> > > =>> only pictures, so I could be wrong, but it seems the
> > > primary restriction
> > > =>to
> > > =>> flow is the center divider between ports is a big chunky
> > > lump on the 2.0
> > > =>and
> > > =>> is more streamlined on the 1.8. So, it could be lower
> > > flow without the
> > > =>> benefit of higher velocity.
> > > =>> Anyway, having now shot my mouth off again in favor of
> > > the 1.8 head, I
> > > =>still
> > > =>> would like to see dynos comparing the two heads.
> > > =>> Dan
> > > =>>
> > > =>> ----- Original Message -----
> > > =>> From: L F <rocco16v@netzero.net>
> > > =>> To: Dave Ewing <MK1Scirocco16v@attbi.com>;
> > > <scirocco-l@scirocco.org>
> > > =>> Sent: Saturday, June 28, 2003 7:34 AM
> > > =>> Subject: Re: 1.8L head on 2.0L block
> > > =>>
> > > =>>
> > > =>> Dave,
> > > =>> You are right; the exhaust is positively expelled,
> > > whereas the intake
> > > =>only
> > > =>> relies on vacuum to fill the cylinder (NA engines).
> > > =>> However, the intake isn't more "restrictive" per se, it just
> > > =>doesn't have
> > > =>> the irresistable force in action that the exhaust has.
> > > This is why the
> > > =>> intake valve(s) is almost always larger than the exhaust
> > > valve(s)....the
> > > =>> intake needs all the help it can get.
> > > =>> You stopped short on one sentence; the exhaust has to exit
> > > =>the tailpipe
> > > =>> into the atmosphere....not just into a pipe. (that's why
> > > low restriction
> > > =>> mufflers/cats, mandrel-bent large diameter tubing, etc.
> > > are important)
> > > =>> It's one reason to try to put the end of the tailpipe in
> > > a low-pressure
> > > =>area
> > > =>> of the vehicle rather than a high-pressure area;
> helps scavenging.
> > > =>> Good disscussion.
> > > =>>
> > > =>> Larry
> > > =>> sandiego16v
> > > =>>
> > > =>> ----- Original Message -----
> > > =>> From: Dave Ewing
> > > =>> To: scirocco-l@scirocco.org
> > > =>> Sent: Saturday, June 28, 2003 1:10 AM
> > > =>> Subject: Re: 1.8L head on 2.0L block
> > > =>>
> > > =>>
> > > =>> Along with Chris's statement, wouldn't you think that the
> > > =>pressure that
> > > =>> the
> > > =>> piston creates when forcing the exhaust out of the
> > > cylinder is greater
> > > =>> than
> > > =>> the vacuum that is created via the throttle body? As far as
> > > =>exhaust is
> > > =>> concerned (atleast the type of exhaust that most of us
> > > are running,
> > > =>fairly
> > > =>> free flowing) I would have to say that the intake is
> > > more restrictive
> > > =>than
> > > =>> exhaust. I realize you can increase intake flow by
> > > adding a cam or
> > > =>bigger
> > > =>> TB or whatever but it is limited to some extent or another,
> > > =>the exhaust
> > > =>on
> > > =>> the other hand only has to exit the head into a pipe.
> > > It doesn't have
> > > =>to
> > > =>> pass through the air filter, intake boot, TB,
> intake, etc. I
> > > =>don't know
> > > =>> if
> > > =>> this is relevant but something that makes sense to me.
> > > =>>
> > > =>> One other point to consider is that I would rather have the
> > > =>exhaust flow
> > > =>a
> > > =>> little better than the intake (whether the intake ports
> > > are hogged out
> > > =>or
> > > =>> not, either way) so that the heat is leaving the motor more
> > > =>efficiently.
> > > =>> 16v motors run hotter due to their increased compression and
> > > =>the higher
> > > =>> rpms
> > > =>> needed to make useable torque.
> > > =>>
> > > =>> I understand the importance of velocity, speed, etc.
> > > but when you
> > > =>consider
> > > =>> that you could make a smaller port flow better than a
> > > larger port then
> > > =>> this
> > > =>> would be an argument against the 1.8 head considering that
> > > =>the 2.0 heads
> > > =>> are
> > > =>> newer and more technology has gone into the port
> > > design. I don't know
> > > =>the
> > > =>> specifics but wouldn't you agree that VW wants to
> > > consistantly improve
> > > =>> their
> > > =>> motors especially with tighter emmissions standards?
> > > =>>
> > > =>> Actually, all of this is rather irrelevant as most power
> > > =>hungry listers
> > > =>> have
> > > =>> already ported and polished their 1.8 or 2.0 heads so
> > > stock standards
> > > =>> don't
> > > =>> really apply but I, again, would much rather have a newer
> > > =>head on my car
> > > =>> that hasn't seen as many miles or as many kids beating
> > > it to death.
> > > =>Since
> > > =>> the 1.8 heads came on the scirocco/jetta/golf and the
> > > 2.0 heads only
> > > =>came
> > > =>> on
> > > =>> the jetta/golf/passat, I'd think that the 1.8 heads on
> > > the sciroccos
> > > =>have
> > > =>> taken the most beating.
> > > =>>
> > > =>> Dave
> > > =>> ----- Original Message -----
> > > =>> From: "Chris DeLong" <green536@hotmail.com>
> > > =>> To: <amalventano@sc.rr.com>; <jdbubb@ix.netcom.com>;
> > > =>> <scirocco-l@scirocco.org>
> > > =>> Sent: Friday, June 27, 2003 3:52 PM
> > > =>> Subject: Re: 1.8L head on 2.0L block
> > > =>>
> > > =>>
> > > =>> > Ok so then you are saying that increased air velocity due
> > > =>to port size
> > > =>> and
> > > =>> > shape DOES NOT flow more air? Hmm, I would think that
> > > INCREASED air
> > > =>> velocity
> > > =>> > would yeild more flow due to the forced induction
> > > =>characteristics that
> > > =>> you
> > > =>> > mentioned below.
> > > =>> >
> > > =>> >
> > > =>> >
> > > =>> > Chris DeLong
> > > =>> > Fine Tuning
> > > =>> > 206.367.5503
> > > =>> > www.finetuningperformance.com
> > > =>> > Seattle, WA USA
> > > =>> >
> > > =>> >
> > > =>> >
> > > =>> >
> > > =>> >
> > > =>> > >From: "Allyn" <amalventano@sc.rr.com>
> > > =>> > >To: "Chris DeLong" <green536@hotmail.com>,
> > > =>> > ><jdbubb@ix.netcom.com>,<scirocco-l@scirocco.org>
> > > =>> > >Subject: Re: 1.8L head on 2.0L block
> > > =>> > >Date: Fri, 27 Jun 2003 14:05:54 -0400
> > > =>> > >
> > > =>> > > > More airflow=better efficiency=more power.
> > > =>> > >
> > > =>> > >umm
> > > =>> > >depends on runner diameter/taper / rpm
> > > =>> > >rpm change = different intake air pulse size/speed,
> > > therefore some
> > > =>> > >configurations make more power at low rpm, where
> > > some others make
> > > =>more
> > > =>> > >power
> > > =>> > >at higher rpm.
> > > =>> > >just boring the crap out of intake doesnt give you
> > > more airflow in
> > > =>all
> > > =>> > >situations. narrower intake passages cause faster air
> > > =>velocity while
> > > =>> > >filling
> > > =>> > >the cylinder, and that very momentum can actually
> > > cause a forced
> > > =>> induction
> > > =>> > >effect, as it squeezes that much more air in the cylinder
> > > =>just before
> > > =>
> > > =>> the
> > > =>> > >intake valve closes. this is how some engines can
> > > have a volumetric
> > > =>> > >efficiency approaching (and possibly exceeding) a
> > > value of 1. the
> > > =>> narrower
> > > =>> > >intake is not perfect though, as it begins to
> > > restrict airflow at
> > > =>> higher
> > > =>> > >rpm.
> > > =>> > >
> > > =>> > >so... from an intake perspective, a stock 1.8 head
> > > is meant to flow
> > > =>> most
> > > =>> > >efficiently at a higher rpm than a stock 2.0 head is
> > > meant to.
> > > =>> > >Al
> > > =>> > >
> > > =>> > >
> > > =>> > >
> > > =>> > >_______________________________________________
> > > =>> > >Scirocco-l mailing list
> > > =>> > >Scirocco-l@scirocco.org
> > > =>> > >http://neubayern.net/mailman/listinfo/scirocco-l
> > > =>> >
> > > =>> >
> > > _________________________________________________________________
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