[s-cars] Bottom-End...

[Mihnea Cotet]

Actually, if he's using the 7A head, stock undished pistons and metal head 
gasket, the CR will be 9.0:1.

The 7A head has the same combustion chambers volume as a 3B/AAN/ABY/ADU and 
the difference in CR in 20vt vs. 20v NA engines is only due to pistons dishes.

The 9.0:1 is due to the metal head gasket that's thicker than the original 
paper unit, and the RS2 (equipped with a metal gasket from the factory) had 
9.0:1 CR.

HTH,

Mihnea

At 08:33 14/01/2004 -0800, you wrote:
>Do it, you wuss.
>
>Might want to consult mlp on this one, as you're not
>going to have 10.3:1 or 9.3:1 for your compression
>ratio, but somewhere in between because your mix and
>matching heads/pistons.
>
>I would swain tech those pistons, too, and keep boost
>down to 15psi...or go with 8.5:1 pistons?
>
>Pizzo
>
>--- Cody Payne <cpayne at bconnected.com> wrote:
> > I see that the 20V 7A is 10.3:1 where the 20VT AAN
> > is 9.3:1
> > http://20v.org/specs.htm
> > http://www.s-cars.org/urs4s6/Tech/tech.html
> >
> > A VW Compression Ratio Article:
> > http://www.tunacan.net/t4/tech/cr.htm
> >
> > So I guess this tells me that if I am running 10.3:1
> > that:
> > -1) May have a detonation issue and need to
> > adjust/retard the timing a
> > bit
> > -2) Heat could be an issue
> > -3) Engine Longevity could be an issue?
> > -4) Increase HP and bottom end torque?
> > -5) More potential then normal to bend stock rods w/
> > above increases?
> >
> >
> > Let the fun begin...
> >
> > cp
> >
> > -----Original Message-----
> > From: mlp qwest [mailto:mlped at qwest.net]
> > Sent: Tuesday, January 13, 2004 10:06 PM
> > To: mlped at qwest.net; Charlie Smith; Cody Payne
> > Cc: Audi S Car List
> > Subject: RE: [s-cars] Bottom-End...
> >
> >
> > Whoops -
> > http://www.sae.org/automag/newenginereview/audi.htm
> >
> > ~-----Original Message-----
> > ~From: s-car On Behalf Of mlp qwest
> >
> > ~FWIW, Audi still seems to be doing something like
> > this with its "low"
> > vs. ~"high" output 1.8t motors.  I.e., the high
> > output apparently runs a
> > CR of ~8.9:1 and a K04 turbo to make 225hp/165kW &
> > 280Nm/207 ft-lb while
> > the "low" ~output 1.8t runs a 9.5:1 CR with the
> > smaller K03 to make
> > 180bhp/132kW and ~235Nm/173 ft-lb. ~ ~Why, lower
> > compression? ~ ~Mike ~
> > ~ ~~-----Original Message-----
> > ~~From: s-car On Behalf Of Charlie Smith
> > ~
> > ~snips
> > ~
> > ~~If you need to rebuild the rest later, you
> > absolutely will .....
> > ~~fitting oversize forged lighter, lower
> > compression, pistons ~
> > ~~    - Charlie
> > ~
> >
> >
> > _______________________________________________
> > S-CAR-List mailing list
> > S-CAR-List at audifans.com
> > http://www.audifans.com/mailman/listinfo/s-car-list
>
>
>=====
>-------------------------------------
>The following statement is false.
>The preceding statement is true.
>-------------------------------------
>
>__________________________________
>Do you Yahoo!?
>Yahoo! Hotjobs: Enter the "Signing Bonus" Sweepstakes
>http://hotjobs.sweepstakes.yahoo.com/signingbonus
>_______________________________________________
>S-CAR-List mailing list
>S-CAR-List at audifans.com
>http://www.audifans.com/mailman/listinfo/s-car-list