On Tue, 15 Sep 2009 22:11:00 -0700, "Bill Noble"
wrote:


wrote in message
...
On Sep 15, 10:18 pm, "Bill Noble" wrote:

snip

So, any ideas? (I've used spray carb cleaner and fuel injector cleaner,
the former works a lot better than the latter) - I've tried wire probes
(access is quite limited), a micro rotor-rooter type thing I made from a
speedo cable, and other mechanical means - none worked worth a darn.

so, there is no politics, and it has a modest relationship to real metal
working, and someone may have an idea to help....

--
Billwww.wbnoble.com

Rifle-cleaning brushes on the end of a flexible cleaning rod is about
the only other thing I can think of, saw something similar for
cleaning oil passages on one of the big 3's V8s in an overhaul book
one time, so they're out there. Combine that with the carb cleaner of
choice. If the other end of the passage is open or can be made so,
maybe a shot of ground walnut hulls or corncob with some air can clean
the carbon out. At a guess, a Porsche?

Stan

----------------------

yep, good guess. Last of the air cooled ones. Sadly, the mechanical
approach won't work unless I remove the engine - there just isn't access -
if I pull the manifold, I can see the ports above the exhaust valves, and
I've tried mechanical means of working on the ports - but they make a couple
of turns pretty quickly after then enter the head so that doesn't work.
Trying to go the other way is worse - the bank of cylinders that has the
more severe problem is the one farther from the pump (obviously), and to get
to it involves running the rod through about 3 feet of cross over tubing,
then a 90 degree bend, and there is no access to disconnect the tubing. I
guess this is what happens when you put a 500KW power plant in an engine
compartment that originally held a 45 HP VW engine.... it's like working on
a fighter - everything is squirreled away behind something else. You even
have to pull the mufflers to change the spark plugs....

I would love to try blasting the carbon out, but I can't figure out a way to
blast effectively into a 1/8 inch hole that is directly behind a valve stem
(thus no straight line access).


So is the carbon in the ports, or in other passages? If you are
getting excessive carbon in the ports you are either running too rich
or burning oil???