Right - the problem is that the heads will move away from the block with the
cylinders as the crank pushes the pistons outward. Compressed air is
unlikely to do the trick - the seal between pistons/rings/cylinder walls is
not an airtight one in the first place. The rings only inhibit the movement
of air past them, making it practically null in the nano-seconds of
compression and power stroke. The amount of air loss with everything just
sitting statically there is likely to be too great to do the job. And, if
you could seal the parts up to an acceptable level of air-tightness, the
pressure required to separate them might be unavailable, not to mention
dangerous. HMMM - how 'bout grease? If a person were to make a zerk-fitted
spark plug-threaded adapter with which to pump grease into the cylinder
(both valves are of course closed anyway), the grease might be dense enough
to do the job. The hydraulic pressure would be much greater than the 150 psi
max likely to be available from an air compressor, and the volume of flow
would be small enough that if the parts "popped" apart, they wouldn't tend
to move very far. Just a thought - I've never tried this, just made it up on
the fly. Use at your own peril!

Coby Smolens
Valley Wagonworks
VW Bus and Vanagon Specialists
"Intimately acquainted with VW Vans since 1959"

1535 SF Drake Blvd, San Anselmo, CA 94960
415-457-5628

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
Of Ed Sato
Sent: Monday, August 27, 2001 1:40 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Separating heads from cylinders

That would work with solid blocks. But the jugs on VWs need to be secured
to the case somehow. You could also use compressed air if you have the
cylinders somehow tied to the case. Aloha, Ed