1.8 Vs. 2.0 Revisited AKA why 1.8 instead of a 2.0 head

[Rabbit16v@attbi.com (Rabbit16v)]

I feel I need to chime in here.

First, I think Haygood's got a good point about the availability of the
heads and that this would defineately need to be taken into consideration
before using TT's record of what type of head they used in 93.

Secondly, most of what is on our cars are not in stock form so stock numbers
are actually rather irrelevant unless you are going to go through the hassle
of rebuilding a head, installing cams, springs, etc. etc. and not touch the
ports.  Even then, unless you can find a 1.8L 16v motor with low miles, I
would defineately think that the lower mileage 91-93 2.0L heads would be
more attractive since they are newer with less wear and tear.

Lastly, using both the EC stats and the TT charts you can see that the
amount of difference in the 1.8L heads favor when comparing the intake ports
is dwarfed by the amount the 2.0L flows over the 1.8L on the exhaust side.
I realize that you have to get air into the head before it can leave the
head but two things are significant here.  One is that on both heads the
intake ports flow better than the exhaust ports so the air that is coming in
is larger than the air going out.  Plus, the air going out is based on the
piston shoving it out which is (I believe) a stronger force than the vacuum
created by the piston to get air into the head (thus the larger intake ports
for the lesser force vacuum has). Secondly, a better flowing exhaust port
will scavenge the heat away from the head/motor better.  That means lower
heat and a more efficient burning of the fuel.  I think we all know how
significant it is to get cooler air into the combustion chamber.

Overall, I don't think you can beat the 2.0L head since no one that realized
that the differences are miniscule and are a little tipped in the 2.0L
head's favor.  What that means is that you can get more money for your 1.8L
head and pay less for a 2.0L head.  I got mine for free and it only had 60K
on it!!

Oh, and one last little item.  Although I agreed with BH that the
availability was an issue, I need to correct him when he says that a larger
port is better.  Larger would be better with high boost race cars and even
then the shape is still more important.  The fact that the 2.0L head has
more material in it's ports is a very good thing not only for even better
shaping but also for added cooling.  Remember that hot oil and coolant run
through the head and weave in and out of the ports throughout the head.
Plus, a little low end torgue is nice when you have the monster top end
power that a 2.0L 16v with the right mods can give you!  HTH!!

Dave
----- Original Message -----
From: "Haygood" <haygood@aemail4u.com>
To: <JoshuaA.Conner@VerizonWireless.com>
Cc: <scirocco-l@scirocco.org>
Sent: Thursday, January 16, 2003 1:59 PM
Subject: Re: 1.8 Vs. 2.0 Revisited AKA why 1.8 instead of a 2.0 head


> keep in mind that the article was from '93.  TT could prolly get the
1.8heads more cheaply since the 2.0l heads hadn't been around as long and
weren't in as many cars (I'm guessing) at that time.  Also, 2.0l needs more
material removed before benefits are seen in flow bench.  2.0l head is not
simply worse flow in stock form.  Flow benches only measure constant peak
flow.  Real engine operation involves pulsed flow and factors like low rpm
performance.  The 2.0l head was built for low end torque.  I'm just saying
that's what it was for, not that that is what we want.
>
> BH
>
> --- JoshuaA.Conner@VerizonWireless.com wrote:
> >Taken from E/C Jan 1993 article written with Techtonics.  All numbers
were
> >derived from testing on a Superflow SF-300 flow bench.
> >
> >
> > Intake port flow testing on Superflow Flow Flow
> >bench at 28-inches
> >
> >Valve lift .100-in .150-in .200-in
> >.250-in .300-in .350-in .400-in
> >
> > 1.8 16V Head 75.7 107.8 138.2
> >161.2 175.3 181.0 183.4
> > 2.0 16V Head 67.7 101.4 130.7
> >143.3 163.2 197.9 171.1
> >
> >TT Streetport 16V 75.8 110.9 146.5
> >175.0 190.6 199.1 209.4
> >
> >
> >
> > Exhaust port flow testing on Superflow Flow Flow
> >bench at 28-inches
> >
> >Valve lift .100-in .150-in .200-in
> >.250-in .300-in .350-in .400-in
> >
> >1.8 16V Head 67.4 96.1 114.9
> >121.1 124.2 125.2 126.3
> >2.0 16V Head 60.9 91.1 115.9
> >129.3 136.5 138.3 140.8
> >
> >TT Streetport 16V 66.8 99.2 125.4
> >138.7 152.3 160.2 165.6
> >
> >
> >It is interesting to note that TT at the time of this article was using
1.8
> >16V cores for there Streetport 16V($1000).  Thus it seems there is quite
a
> >valid argument for using the 1.8 stock head versus 2.0 stock head.  That
> >being "out of the box" performance is greater with the 1.8.  Porting is
very
> >much a craft "BEST" done by those very experienced and with a flow bench.
> >However if you got a spare head give it a shot, you never know until you
> >try.   Summary:  if you got serious porting skills or serious cash for a
> >already ported head prolly get a 2.0.  Cheapasses on a budget get the 1.8
> >and go fast( not as ultimately fast, but remember the budget?)
> >
> >Joshua C.
> >'88 Red 16V 2.0block 1.8 head
> >
> >
> >
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