Date: Wed, 5 Jul 2006 13:12:19 -0400
Reply-To: Kragen Sitaker <kragen@POBOX.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Kragen Sitaker <kragen@POBOX.COM>
Subject: Re: need new engine for air-cooled van (overheated one)
Dennis Haynes writes:
> That piston meltdown had nothing to do with driving over 45 mph during break
> in. This was ignition timing or maybe mixture related. The head also appears
> to show some combustion gas leakage past the top cylinder seal.
You're right! I hadn't noticed that. Thanks for taking a look at the
photos.
> This is often caused by a warped case. The combustion leakage may
> have contributed to the excessive temps that melted the piston
> and/or cracked the head. These engines rely heavily on a working EGR
> system to control combustion temperatures. It needs to be there and
> working for any extended highway travel.
Damn. Well, our EGR valve hasn't been hooked up for many thousands of
highway miles --- the linkage press-fits into two little plastic
inserts, one on the EGR valve lever and one on the throttle, and the
little plastic insert on the throttle is missing. We tried wiring it
into place with some electrical wire soldered into loops, but it came
loose again within a few hundred miles.
Did you notice the missing linkage in the photos?
Presumably the new engine won't have that problem, but I'm curious how
we should have solved it.
> Keeping these engines alive require a bit of a laid back, slow but steady
> driving style. When power is needed, let it rev, never lug it. Yes, it can
> be lugged at 3,000 rpm.
We had been driving like that --- but we didn't know this:
> At any speed, if more throttle does not make more speed, the engine
> is being lugged, slow down or down shift.
Thanks! This was pretty much always the case.
> The control flap over the oil cooler is deceiving. As the t-stat lets the
> flaps open, it appears to cover the outlet to the oil cooler. Actually, it
> moves away from the fan housing. There is duct space underneath that
> actually supplies air to the cooler.
Hmm, OK. Well, the thermostat was actually missing, so this flap was
all the way down on top of the cooler:
http://flickr.com/photos/blmurch/181761652/in/set-72157594187260002/
Does that mean it was stuck on "maximum cool", or "minimum cool"?