valve job question

[Matthew Harding]

>off the carbon that was on top of the cylinders. I used to rotate the engine
>around and bring the pistons up to tdc and whirl away with a drill bit
>mounted wire brush.
>
>
>nowadays I wonder if all it did was make the piston top pretty and introduce
>lots of debris into the engine especially the cylinder walls, creating years
>of wear in minutes.

Like you i've been known to do the same thing with the drill bit mounted
wire brush whilst the head is off (on my own motors), just filling in time
i guess and more than anything making it look shmick for any one who comes
by :P

when I do I simply make sure that I have someone else holding the
compressed air across the top of the piston at the same time, and rags down
the adjacent cylinders.  generally most of the debris gets blown away, and
any that is down the gap can be blown out with the compressed air.

When you rotate that piston to the bottom again, just carefully wipe up the
bore with a clean rag, that will get any lingering debris.

If you are really concerned, just turn the engine over by hand a couple
more times, and look for any more being dropped by the piston as it goes
down the bore.

just my thoughts :)

One thing i do think it can help with is a high compression engine pinging,
because (for a short time) there is no carbon deposits to stay hot enough
to ignite the fuel/air.

again just my thoughts, and some observation...

cya