strange question.
in terms of them both  being a four stroke gasoline opposed four engine ..
yes.
in terms of the cooing fan mounted on the crankshaft ( assuming you are
asking about the Type IV air-cooled engine used in the Vanagon and from 72
on in Bay Buses ) ...
the air cooling has a small sound of it's own...
from the fan and air blowing through the engine.

that shriek that older 911 Porsches make..
that has a lot to do with the cooling fan they use and how fast it's being
driven..,
being part of the alternator, it's driven about 30 % faster than crankshaft
speed, like most alternators.

why do you ask anyway ?

here's one, when the metal sealing rings at the tops of the barrels leak on
an air-cooled VW engine ..you get a popping sound under acceleration or
load.
on a waterboxer it's doesn't make a sound when they do that ....
until it overheats....then there's gurgling and other sounds of an
overheated water cooled engine in distress, like the owner crying.

Scott
www.turbovans.com
----- Original Message -----
From: "Mark L. Hineline" <hineline@OCOTILLOFIELD.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, November 21, 2010 7:13 PM
Subject: Sound

> Does a WBX engine sound like an AC engine?
>
> Mark