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Question for all those with a 16v 2.0 block and 16v 1.8 head
Add n2o... ;D
brian
On Mon, 13 Jan 2003, Rabbit16v wrote:
> snip
> Dave,
> I have the article on the TT head as well. You're stating that
> the 2.0 head flows better because its exhaust flows 15cfm more while its
> intake is 10cfm, leaving it with a net 5cfm advantage. I'm not so sure
> that it's so simple.
> snip
>=20
> Sure it is! One head next to another!
>=20
> sinip
> My first guess as to the reason people think that the 1.8 head
> flows better is that of the redline of the 2 motors. The 1.8 redlines at
> 7200; with Motronic, the 2.0 redlines at 6800. There's no sense getting
> into a discussion of whether that has any bearing on how well the head
> breathes (or whether the redline is in a reasonable place anyway), but th=
at
> certainly would give the impression that the head flows better.
> snip
>=20
> You answered the reasoning behind this yourself. CIS-E vs MOTRONIC. The
> redline has only to do with the computer/fuel system not the motor.
> Granted, the redline is based on the expectations of the motor but since =
the
> 2.0L 16v was built for torque and put into significantly larger vehicles
> than the 1.8 a redline of 400rpm less is understandable.
>=20
> snip
> Secondly, if you look at the intake ports themselves, the
> difference is *enormous*. It certainly looks like there would be more th=
an
> a 10cfm flow difference, and that's probably convincing people as
> well. The exhaust difference is not as noticeable.
> snip
>=20
> Size does NOT matter under these circumstances, believe me! A friend of
> mine races aircooled VWs and has always welded and D ported his heads unt=
il
> we started messing around with a flow bench (a Gene Burg flow bench!) and
> now he has relatively stock heads with stock sized valves and they out fl=
ow
> anything he's ever messed with. The heads were ported by Brian Steele (a
> friend of Gene Burg) for racing in the 70s. Now if you just want to make
> raw HP and using Turbos etc. then bigger is obviously better but for N/A
> stuff, the how is more important that the size.
>=20
> snip
> Thirdly, the fact of the matter is that the 1.8 head does make
> better power at high rpms. I've yet (unfortunately) to see a back-to-bac=
k
> same-car 1.8 head vs. 2.0 head dyno run. But I did do a stock 1.8 engine
> run and a stock 2.0 engine run on my car -- with the same exhaust, fuel
> injection system, everything. All I did was take the manifolds off, rip
> the 1.8 out and put the 2.0 in. Same tranny, same driveline, same
> everything. Therefore, the only difference on the dyno is the motor.
>=20
> What you see in the dyno runs is that the 2.0 has an enormous
> torque advantage over the 1.8 over most of the engine's range. In fact,
> the 2.0 made more torque at idle than my 1.8 did at its peak. However (a=
nd
> this is the reason that the stock 2.0 cars didn't knock any significant
> time off the 0-60 numbers vs. the 1.8) at high revs, this advantage begin=
s
> to dwindle, and by 7200rpm, the 2.0 head isn't making much (if any) more
> than the 1.8 did. Exhaust restriction comes into mind as a factor... but
> other than that, the only thing to explain that drop in advantage is that
> the 1.8 head is flowing better.
> snip
>=20
> Why would exhaust restriction come to mind? I thought you said everythin=
g
> was the same but the motor? At the same time you need to realize that th=
e
> 2.0L has more spinning mass. This doesn't add up to much as far as power
> loss is concerned but when comparing the two as closely are you are (a
> couple hundred rpm) then you need to take that into consideration. For
> example, the small block chevys are known for their high rpm potentials.
> Not that the big blocks can't, but it takes a lot more work on all aspect=
s
> of the engine to make a big block wind up like a small block. Same thing
> with 4 cylinders. What I am saying here is that the head, by itself, is =
not
> what made it fall flat at 7200. Plus, there is a possiblity that the blo=
ck
> had a mechanical problem or that something wasn't working just right in y=
our
> fuel system. Usually things start or go bad when you mess with them!
> Either way, this isn't enough to prove the point your trying to make. Wh=
at
> we need is for someone with a 2.0L with a 2.0L head and a 2.0L with a 1.8=
L
> head do back to back runs with identical mods and transmissions.
>=20
> I have had all possible setups in my car. I had a 1.8 with a 1.8 head, t=
hen
> a 2.0 with a 1.8 head and now a 2.0 with a 2.0 head. The 2.0 is much
> quicker than the 1.8 with similar porting and no other mods other than HD
> valve springs. If you have a 1.8L head and want to use it, go ahead, por=
t
> it, put cams it and use it. I'm not saying that the 1.8 isn't any good, =
I'm
> just saying that the 2.0L flows better than the 1.8L in stock form. Sinc=
e,
> for the most part, most of our cars are NOT in their "stock form", which
> head flows better is actually rather irrelevant. I chose the 2.0L head
> because of the TT chart AND because it is a lot newer than the 1.8. Sinc=
e
> it came from a 92 GTI with low miles, I didn't have to worry about the
> tensioner stud striping on me and having my new valves slam the pistons, =
I
> didn't have to worry about the cam bearings being all used up and littere=
d
> with streaks from crap running through the oil or how many times the valv=
e
> seats had been ground. It was easy, new valves, touch up the seats a
> little, deshroud and port with new guides. Plus, all the exhaust studs w=
ere
> still there in perfect condition!
>=20
> snip
> Furthermore, 87 octane is not the best gas for the 16V. If
> someone made more power using 87 on the dyno than 93, their engine is not
> tuned properly. With stock ignition advance and compression ratio, the 1=
6V
> will ping non-stop on 87. The knock sensor will retard the iginition to
> stop this, but in the process you'll lose power...
>=20
> It is true that the energy contained in 87 octane gas is
> (fractionally) higher than 93... but not nearly enough to make up for the
> difference in power lost by the knock sensor. If your car doesn't enter
> ignition retard mode on 87, something's up...
> snip
>=20
> Again, just saying all of this doesn't make it so. I run 87 in my 2.0L 1=
6v
> with CIS-E and it does fine with no knocking. I can even watch the timin=
g
> with a timing light and see it advance correctly. I realize it is differ=
ent
> under a load but this alone disproves your theory. Second, 87 octane has
> more energy and creates less heat so a higher octane fuel that would crea=
te
> more heat would also create a possibility to knock, thus be retarded also=
=2E
> Whatever you do to your car (suspension, wheels, tires, intake, cams,
> adjustable cam sprocket, etc.) to gain something, you will always be losi=
ng
> something on the other side. Gain more hp, lose torque. Add cams, lose
> torque, lose idle, gain more hp on top end, etc. etc. etc.
>=20
> In order to compare two things everything around those two things need to=
be
> identical. In your comparison everything was identical except for the blo=
ck.
> Give me something I can't disprove then I'll be more likely to believe it=
=2E
> Especially if your trying to go up against my pals at TT!! :)
>=20
> Dave
>=20
> At 05:53 PM 1/10/2003, Rabbit16v wrote:
> >The 2.0L head flows better than the 1.8L head in it's stock form. You g=
ot
> >that backwards. I don't know how many times the link to the TT flow tes=
t
> >site has been put up here on the list but it shows without a shadow of a
> >doubt that the 2.0L head flows better than the 1.8L head. And, with the
> >2.0L head being just plain newer than the 1.8L head, the 2.0L head is a
> >better choice you don't have to worry as much about the tensioner stud
> >pulling out or the cam bearings being worn so much, etc. And this is
> >without even mentioning the fact that the 2.0L head has more material fo=
r
> >porting than the 1.8L head. See, even though the 2.0L head has smaller
> >intake ports it depends on how it is ported not necessarily how big but =
it
> >does have larger exhaust ports so overall the 2.0L head flows better. S=
o
> if
> >you find a 2.0L 16v tallblock somewhere, just slam the whole thing into
> your
> >car and swap the manifolds.
> >
> >I wonder how this whole 1.8 is better than 2.0 thing got started? Maybe
> >someone who ain't into 16v. Hmmmmmmmm, MEZE?????
> >
> >HTH!!
> >
> >Dave
> >----- Original Message -----
> >From: "Allyn" <amalventano@sc.rr.com>
> >To: "Joe Doty" <Joe.Doty@lcnetwork.com>; "Nathan Frechette"
> ><desertwind16v@attbi.com>; <scirocco-l@scirocco.org>
> >Sent: Friday, January 10, 2003 10:36 AM
> >Subject: Re: Question for all those with a 16v 2.0 block and 16v 1.8 hea=
d
> >
> >
> >i've been wondering about this myself lately. the head chamber volumes o=
f
> >1.8 and 2.0 heads are both 45cc. so the head doesnt change c/r.
> >the advantage of a 1.8 head on a 2.0 block is that the 1.8 flows better
> than
> >the 2.0 in their respective stock forms. this could effectively make a
> >person think the engine has a higher c/r since it would get slightly hig=
her
> >max pressure readings during a compression check.
> >Al
> >
> >
> >----- Original Message -----
> >From: "Joe Doty" <Joe.Doty@lcnetwork.com>
> >To: "Nathan Frechette" <desertwind16v@attbi.com>; <scirocco-l@scirocco.o=
rg>
> >Sent: Friday, January 10, 2003 3:06 AM
> >Subject: RE: Question for all those with a 16v 2.0 block and 16v 1.8 hea=
d
> >
> >
> > > Nathan,
> > >
> > > The combustion chambers on the 1.8 16v and 2.0 16v heads are identica=
l,
> so
> >the head doesn't change the compression. The Bentley says the 2.0 comp.
> >ratio is 10.8:1.
> > >
> > > Joe
> > >
> > > -----Original Message-----
> > > From: Nathan Frechette [mailto:desertwind16v@attbi.com]
> > > Sent: Fri 1/10/2003 12:03 AM
> > > To: scirocco-l@scirocco.org
> > > Cc:
> > > Subject: Question for all those with a 16v 2.0 block and 16v 1.8 head
> > >
> > >
> > > What does the compression ratio come out to be. I have been searchin=
g
> on
> >the tex and haven't been able to find good answers. Thanks
> > >
> > > Nate
> > >
> > > IIi zz j)fj=7F b=CB=9D? (
> >
> >
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> >
> >
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