[tech]: compression ratio: 9a vs. pl

[pbureau@attbi.com (pbureau@attbi.com)]

JH/3a yeilds about 9.5:1 if head shaved, you can get 9.8-
10.1:1 maybe

--
====
ATS - Patrick Bureau
1985 8v Euro GTX 3A/JH Project
1988 16v Euro GT Project
> So what does the compression wind up being when you mate a 1.8 head to a 2.0
> block? 
> 
> 
> 
> Joshua Hignight
> Student Services/IT Services Coordinator
> (505) 821-4800 ext. 2116
> 
> 
> -----Original Message-----
> From: Michael Abatzis [mailto:abatzis2@hotmail.com] 
> Sent: Tuesday, May 07, 2002 3:34 PM
> To: scirocco-l@scirocco.org
> Subject: RE: [tech]: compression ratio: 9a vs. pl
> 
> >From: "Scott F. Williams" <sfwilliams@comcast.net>
> 
> > > how high a cr can you
> > > run w/o blowing headgaskets/pinging,
> >
> >I'd be nervous to run anything more than 11.5:1 on the street. Ability to
> >reach even that point requies some high-octane fuel. A healthy combustion
> >chamber (no glowing carbon deposits or other problems), proper engine
> >fuel/ignition mapping, and adequate cylinder head cooling should permit 
> >this
> >CR on 94 octane.
> how much needs to be taken off a stock head to get this cr?
> 
> >
> > > hmmm--this is actually a thread that hasn't been beaten into the
> > > ground before, has it?
> >
> >I don't think that the CR topic has been beaten into the ground at all. In
> >fact, I was just sweating about the same thing. See the recent thread
> >entitled "Cincy: hotrod plans/what to do? ACK!". I was considering the
> >purhase of a motor that supposedly had a 12:1 CR. It turns out that the
> >ratio is actually higher. Thus, I'm passing on the deal.
> >
> >P.S. The difference in CR between PL and 9A motors is due to the different
> >bore and stroke -not a larger combustion chamber volume in the PL. The 9A
> >bottom/1.8l head combo is demonstrably faster than a 9A bottom/2.0l head 
> >set
> >up.
> 
> i've got a 2l/1.8 that begs to differ--are there any actual dyno reports 
> showing a difference, or just that flow graph (at tt?) that shows 
> intake/exhaust flow?
> -michael
> 
> >--
> >Scott F. Williams
> >NJ Scirocco nut
> >'99 Subaru Impreza 2.5 RS
> >Mazda 323 GTX turbo "assaulted" vehicle
> >Golf GTI 16v "rollycar"
> >ClubVAC: "Roads found. Drivers wanted."
> >
> >
> 
> 
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