>Hmmm... I don't think my bus would go 60 in third without blowing up.  Even
>50 scares me, as I'm sure it is approaching 5000 RPM.  What year van is
>this that you are talking about?

Most buses I've driven '63,'67,'71, (this one is 1971) I have taken to 60 in
third, I used to take the squareback to 70.  I will rev that high if I have
a loaded, (this means four or five people and gear) and I'm on a long hill
that I know fourth won't quite hold if I shift.  I'd rather a lightly loaded
high rev than a bogged down 2250 rpm.  I reprimand any driver of my bus that
shifts too early, or too late on a down shift (~48-52mph into the hill).
I've followed trucks down hills at 90 and the engine sounded great.

>I agree with Eugene that one should watch their valve train closely in
>any case, but I don't see the need for dual springs in any type IV bus
>application.  The motors are not designed to be revved past 5,000 RPM.  
>IMHO, dual springs will just add wear and tear on the valvetrain and
>lead to premature cam or lifter failure.    

I believe my Haynes book, 4400 rpm limit on the bus, after that, HD singles
or duals.

>In a bus, I would go for reliability and get the lowest
>rate springs that could sustain 5,000 RPM (stock springs are more than
>adequate than this).
>
>Berg's pushing of dual springs and pooh poohing of hydraulic lifters
>is making me think they are only concerned with building race engines
>for Beetles, but I don't know that much about them.
>
Berg has done thousands of tests and drives and has driven buses of all
kinds himself.  His 1971 is famous.  I believe him, reliability is relative,
and...... .....4400 rpm, 65mph in a bus, no higher or you'll burn your stock
single spring exhaust valves.  As for the hydraulics, I think he's mostly
talking about the long run, 45,000 miles down the road situation when the
engine is hot, stopped, and then won't hold hydraulic pressure.  I believe
that too.

Sincerely,
Eugene
'71