I always thought VW/Audi went to a 5 valve head for emision reasons and not for performance, might be wrong tho.
Réjean Langis 93 Corrado VR6 [email protected] http://user.fundy.net/langisr ----- Original Message ----- From: "Mark Radelow" <[email protected]> To: <[email protected]> Cc: <[email protected]>; <[email protected]> Sent: Wednesday, June 27, 2001 3:37 PM Subject: Re: OT: 1.8T stuff(my project-for those interested) > Well Five-Valve technology doesn't mean it's the best. After all look at F1 > that TRIED 5-valve heads but after they found out they couldn't get as good > of cam profiles and the cylinder filling wasn't that good they went back to > four-valve heads. Regardless if whether the 20v was built for turbo or not > I believe the head isn't THAT great for anything other than turboing...like > you said :) > > Mark > > > From: John Caldwell <[email protected]> > To: Mark Radelow <[email protected]> > CC: <[email protected]>, <[email protected]> > Subject: Re: OT: 1.8T stuff(my project-for those interested) > Date: Wed, 27 Jun 2001 12:08:24 -0600 (MDT) > > On Wed, 27 Jun 2001, Mark Radelow wrote: > > > I think the jury is still out as to whether the Five-Valve head is really > > that superior to the 4-valve design. In Europe the normally aspirated > > 5-valve 1.8 liter makes approx. 130hp (72hp/liter) compared to the 150 > made > > by the 2.0 (75hp/liter). The 5-valve head has a lot more reciprocating > mass > > in the head along with the rocker design which limits cam profile design. > I > > doubt the costs justify the end result. For me, if I were to turbo a VW > I > > would use a G60 head. Same thing, designed for boost and you can easily > get > > 250 HP out of that motor with a turbo. > > > > That motor wasn't built to be naturally aspirated.. in the great tradition > of giving people 9,000 engine choices to put in their golf, some dudes at > vw and audi said "wouldnt it be cool if we made a NA 20v?" With the same > displacement, as you approach max efficiency for a head on the motor, the > gains arent going to appear that big. If you could rev a 20v to 10krpms > or above, I guarantee that it would make more power than a 16v. That > whole game changes though when you start cramming air into the motor... > you don't need to rev it to 10k to get the power out of it. > > > _________________________________________________________________ > Get your FREE download of MSN Explorer at http://explorer.msn.com > > _____________ > List Sponsor: http://www.netsville.com > To remove yourself from this list, send mail to [email protected] with 'unsubscribe a2_16v' in the body of your message > See us on the web at http://www.a2-16v.com > Visit the 16V Homepage at http://www.gti16v.org > _____________ List Sponsor: http://www.netsville.com To remove yourself from this list, send mail to [email protected] with 'unsubscribe a2_16v' in the body of your message See us on the web at http://www.a2-16v.com Visit the 16V Homepage at http://www.gti16v.org
