Date:         Wed, 23 Jan 2002 06:20:17 -0800
Reply-To:     Dana Morphew <kadm@PUGETSOUND.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dana Morphew <kadm@PUGETSOUND.NET>
Organization: Dana's Mobile Carpet Steam
Subject:      Re: '80 Westfalia-- best way to drive over passes
Content-Type: text/plain; charset=us-ascii

The 4.57 final drive air-cooled tranny has a third gear of 1.26, so the engine
will turn close to 1000 rpm for each 13 mph of road speed if the Vanagon has
stock size tires.  When spinning at 4000 rpm in 3rd you are moving at close to
52 mph.  3000 rpm will be close to 39 mph.  5000 rpm will be close to 65 mph.
All in third gear.

-Dana-

"G. Matthew Bulley" wrote:

> It is only when the driver places an exceptional load on the engine
> (full throttle under heavy load), while keeping the cooling system in a
> sub-optimum range (i.e. 3,000-4,000 rpm) that heat builds up. The crank
> speed is insufficient to push enough air across the cooling surfaces to
> displace the heat; only then does "engine heat accumulate over time".
>
> No-one proposed going 70mph in 3rd, as Stan suggests. What I said was
> reduce your speed to 45 and relax in 3rd at 45mph for the climb (which
> Stan also say he has done??). Again, this puts the cooling system at
> peak capacity, while at the same time reducing the load on the
> crankshaft.

> G. Matthew Bulley


From: Stan Wilder [mailto:wilden1@juno.com]

> I have no idea how long you expect your engine to last but I've seldom
> needed to turn my engine over 4200 RPM to keep up with traffic,
> accommodate persistent head winds and climb hills.

> I just can't envision turning my engine 4400-4800 RPM in third gear to
> maintain 70 MPH or for any other reason for an extended time frame.

> Stan Wilder
> 83 Air Cooled Westfalia


<gmbulley@BULLEY-HEWLETT.COM> writes:

> > Using our current Vanagon Westfalia (4speed manual on a 2.0 l stock
> > box)
> > as an example... on encountering a hill, if you reduce your speed
> > to
> > about 45-48 mph, and put it in 3rd, you have used the transmission
> > and a
> > reduction in speed to reduce the load on the motor. You've made a
> > mechanical exchange, sacrificing time, and distance to essentially
> > reduce the pressure required at the crown of the piston. The motor
> > spins
> > faster, under much lighter load to move you more slowly. That's the
> > idea
> > behind a transmission.
> >
> > Again, in my experience, by reducing my speed, and keeping the van
> > in
> > the "sweet spot" of 4,400-4800 rpm, even if that means downshifting
> > to
> > second, or driving only at 1/4 throttle for flatter stretches, I see

> > Thoughts on this appreciated.

> > G. Matthew Bulley