Re: DOHC or not?

["Billy T." <btylaska@onramp.net>]

no.

Brandon Wilson wrote:

> Can you get the 24v VR6 in the US????
>
> Brandon Wilson
>
> ----- Original Message -----
> From: Christopher Morgan <cmor@home.com>
> To: <jettaglx@igtc.com>
> Sent: Sunday, March 05, 2000 7:26 PM
> Subject: Re: DOHC or not?
>
> > Regardless of what some of the engine covers say, the 12v VR6 is really a
> > SOHC motor.  The front cam has the intake and exhaust lobes for the front
> > cylinders as does the rear cam for the rear cylinders.  In other words, if
> > you look at any one cylinder, the intake and exhaust valves for that
> > cylinder are actuated by a single cam.
> >
> > ...however...
> >
> > The 24v motor is DOHC.  It still has only two cams, but the they are
> > separate intake and exhaust cams (thus allowing the use of variable valve
> > timing).  For any one cylinder, the intake valves are actuated by one cam
> > and the exhausts by another.  It's a pretty clever set-up.  Somewhere I
> saw
> > pics of the valvetrain, which showed how each cam uses regular-length
> valve
> > stems for its 'local' valves and extra-long valve stems that reach across
> > the head at an angle for the valves in the opposite bank.
> >
> > The same write-up also mentioned that the other design goal for the 24v
> > motor (besides the 30 extra hp) was an increase in fuel efficiency.  Did
> > anybody else notice that the 12v VR6 is not a gas mileage champ?  :-)  For
> > comparison, the 174 hp GTI/Jetta GLX 5 spds are rated at 20/28, while the
> > 190 hp Audi A4/Passat V6 5 spds get 20/29.  The 24v VR6 is 204 hp and is
> > supposed to get the same, if not better, mileage as the 12v.
> >
> > FWIW, the number of cams does not necessarily relate to the number of
> > valves.  Using BMW motorcycles as an example, the K75/100 (but not
> > K1100/1200) motors are 2 valve per cyl DOHC, while the newer R-bike motors
> > are single cam 4 valve units.
> >
> > -Chris
> >
> >
> > From: <VW155mph@aol.com>
> > > In a message dated 02/28/2000 4:43:56 PM Eastern Standard Time,
> > > sundie@lunaticfringe.org writes:
> > >
> > > > So my question is this!  Does the VR6 have 2 cams or 4?
> > > >
> > > >
> > > >   Breathlessly awaiting answers....
> > > >
> > > >
> > > >  Sundie...
> > > Just 2..
> >
> >