[Vwdiesel] rabbit head

[James Hansen]

Sorry to hear of this Peter.
Probably too tight a belt, you get wear on the injection pump input shaft
bushing, and it pushes the belt off as the pulley tips.
Belt should be final tight when cold so that you can still slide the belt
back and forth on the grooves of the cam sprocket.  Since the motor grows
taller when it heats up, you set this cold.  If you can't slide the belt
around at all on the cam sprocket, it's too tight.  The new tensioners are
spring loaded, but the old ones, you have to do it just so.

Other reason is the injection pump bracket might be loose, or loose bolts
holding the pump, particularly the one closest to the injector pipes.

You should be able to make one head out of the two, but that was a pretty
hard tap dance.  As long as the lifter bores are still good, you should be
okay and just swap parts.  I would be tempted to renew the exhaust valves,
as they get the hardest life.
-james

-----Original Message-----
From: vwdiesel-bounces at vwfans.com [mailto:vwdiesel-bounces at vwfans.com] On
Behalf Of peter blake
Sent: January-22-12 10:59 PM
To: diesel
Subject: [Vwdiesel] rabbit head

  So I now know what happens when the timing belt jumps a tooth 
or two.  The exhaust valves did a tap dance on the pistons and
managed to snap the cam at the no. 1 cylinder.  
  The real question is why my new belt walked off the pulley and
self machined against the cover.  When I pulled the cover off the
belt was about 1/2" wide and loose. I haven't investigated further.
  I cleaned the top of the block and the bottom of the head and
tried to slip in a .003" feeler gauge and couldn't.  So I'm hoping
it is still flat enuf to be usable.  
  My plan now is to take the head off the Jetta, which has the burnt
out injector hole and remove the valves followers and camshaft and
use them in the rabbit head.  And then put that head on the Jetta so
that I have at least one functional vehicle.
  A couple of problems I have r removing two of the followers from
the head.  The valves punched up far enuf to put a crown in the face
of the follower.  The other problem is whether or not I can even use
the valves at all. I'm hoping to just lap them in and be done with it.
Any thots as to why the belt would walk off the pulleys and then 
stretch?  New belt new water pump and new tensioner, why wouldn't
it track straight?  
Peter
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