Date:         Fri, 26 Jul 1996 22:44:19 -0700
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Douglas <douglas@praxis.net>
Subject:      Re: GEX update (fwd)

natasha!kombi@adobe.mv.us.adobe.com wrote:
> 
> >
> > I just returned from the garage and hada look at the head in question. The
> > intake vlave seat on number was not dropped or dislodged by pushed
> > in a fraction. There was exhaust etc from where the head was not meeting
> > the cylinder. Any one familiar with this one?
> >
> This problem sounds like failure due to pre-ignition (knocking, pinging,
> etc.). 


Detonation -- cheap fuel and to much timing!


> Also check for damage on the piston crown.  VW buses have their
> engines rather far from the ears of their drivers, pull large loads with
> itty-bitty engines, heat up alot, etc. alltogether a bad mixture for this.
> The pinging occurs when the mixture explodes rather than burns.  It sounds
> like a rather tinkly rattling under load (like going up hills).  If you
> don't stop what you're doing (downshift, take the foot off the gas) you
> continue to hammer the inside of the engine.  On most engines, the piston
> crown, being aluminum is the weak point, and you blow a hole in the piston.
> Veedubs break in other formats, including driving a valve through the head.
>


Check your ring side clearance. If it is excessive your got detonation.

If your ring lands are good, it could be as simple as loose head bolts! 

>(snip)
> Good luck -- I hope I'm wrong, and am not expert on this...
> 
> malcolm

-- 
Respectfully

Douglas

                 "He who knows he knows, knows nothing.
                  He who knows he knows nothing, really knows."

                                                            Spooky Tooth