When I used to work as a mechanic (not VW), I would adjust the rockers just
slightly loose on a rebuild, then adjust them down once it had run up the
oil pressure. Of course it was easier on American iron, since you could run
the egine without the valve covers if you used those little clip-on rocker
covers so the oil didn't spay all over the place.

I know of a guy back when I was in high school installed a new cam and
lifters in a V-8, and cranked down the rockers a turn or so past contact.
Started the engine and as soon as the oil pressure came up, the lifters
pumped up and then slammed the valves into the tops of the pistons! Had to
get a valve job right after that, as compression was terrible.

My recommendation would be to leave them a little loose on the initial
startup and let them get pumped up with oil. Once you have established oil
pressure for a good 20 minutes or so, shut off the engine. Go through the
valve adjustment procedure just like it had solid lifters (finding TDC for
each cylinder) except then give the lifter 1 turn past contact. Do this
immediately after shutdown, so the lifters don't have much time to bleed off
pressure. Start it back up and listen for tapping. If there is any, you
should be able to hear which side it is coming from and give that cylinder
another 1/4 turn or so. Repeat as needed.

Compression is relative, depending on your starter motor, battery, gauge,
etc. but you should see over 100lbs and even on all cylinders.

TomC
tcarrington@relitech.com

> -----Original Message-----
> From: Phil Marston [SMTP:pmarston@INSTECH.CO.UK]
> Sent: Tuesday, January 11, 2000 8:11 AM
> To:   vanagon@GERRY.VANAGON.COM
> Subject:      Hydraulic lifter valve clearance settings on a 1600
> aircooled
>
> Please excuse me raising this subject again but there has been so much
> too-ing & fro-ing that I just wanted to summarise what had been said in my
> own mind that I can actually go ahead and put it into practise this
> weekend.
> When I recently re-built my engine I followed the Haynes manual when
> adjusting the tappets and pre-loaded the hydraulic tappets by getting to
> the point where the assembly took up all of the slack and then added a
> couple of extra turns.
> It now appears that general concensus is that I should have in fact made
> not pre-loaded but instead backed off slightly & set a gap of about .006".
> (This is with a cold engine that has been standing overnight).
> Is this correct or have I mis-understood ?
>
> I have not checked the compression yet with my present settings but the
> lack of power and ease of turning over the engine indicates that something
> is not quite right.
> What compression should I be after with a new set of pistons, barrels &
> heads ?
>
> Thanks in advance
> Phil
> 81 Type 25
>