Hi all,
First time I've done work on the B in ages. I decided to clean the head
up a bit, remove the carbon, remains of the gasket etc before I give it
to a friend of mine to turn it unleaded, bigger intake valves and a bit
of port blending/polishing etc.
Well on all the exhaust valves there was a light beige/whiteish-brownish
build up. On #2 exhaust valve this buildup was around 2.5mm thick!
Anyway after removing all the carbon and white stuff etc I was very
surprised to see the #2 exhaust valve was of a different type to the
other 3. The other three are dished whereas this one is flat and
protrudes a further erm .5 ml or so into the chamber. Now I was under
the impression as the second owner of this car (20K miles when we bought
it) that the head had never been removed, I have every receipt since
new. Is it possible the valve was this way from the factory or is it
more likely that this problem (what burnt valve?) occured very early in
the life of the motor and was replaced under warranty? Who knows I
guess. Well the good news I guess is the valves must be sealing ok
because they're not losing a drop of fluid over an hours test.
Can someone explain what the offwhite buildup is on the exhaust valves?
As I'm intending on fitting slightly harder springs to go with a
different, higher lift camshaft, should I also replace the exhaust
valves while it's all apart? I was intending on replacing the lot along
with the guides and I figure it's false economy not to replace the
valves now.
Cheers,
Neil.
|