I've just about stripped down the Audi head, now, before rebuilding, I'll be cleaning up the old ones. The exhausts have the usual thick, hard, ceramic like coating on them, the inlets were a surprise, with the head being fairly clean, but the back of the valve, in the inlet port, there is quite a lot of tar like build-up on each valve.
Whats the best way to clean these up? Thanks Alan.
Carefully mount them in an drill with a bit of tape wrapped round them to stop them being scratched by the jaws & wire brush them. All normal caveats about goggles & common sense apply.
Wire wheel on a bench grinder. Mike.
IME the chances of damaging valve stems by gripping them in a drill chuck without any protection must be virtually zero. I've never damaged any by not using any, and I don't know of anyone who has. Mike.
Dishwasher? Handy divorce aid. ;)
You've got to try, but never underestimate the power of idiocy. You can chew up suprisingly hard things with keyless chucks.
As others have said, mount them in a drill (bench drill is best, but a normal drill stuck in a vise and the trigger held on is just as good).
For the inlets, give them a rough scrape with something sharpish (screwdriver/small scraper) to get the worst of any soft gunk of, then wire brush.
Exhausts, some coarse(ish) wet and dry (180-240 grit) or sandpaper (600 grit region). Just rub them enough to clean them.
If you want a spotless/mirror like finish, use some even finer wet and dry once you've got the worst of the gunk of.
** Posted from
The wife's dishwasher on a hot cycle. (pop the cylinder head in too, infact pop all the nuts and bolts in- they come up shiney new)
Tim..
I think keyless chucks are an abomination. Even those made by Albrecht, which are considered to be one of the best if not 'the' best manufacturer of them, are still no match for a decent cheaper keyed chuck IMO. The problem being that you have no control over how tight a keyless chuck grips. Mike.
WEll I don't generally put things that can be damaged by a chuck in one. And all my large drills still have keyed chucks. The Metabo Futuro all metal ones aren't bad though. Albrecht make very nice chucks but I don't own anything that runs that concentrically that doesn't get a collet.
That's exactly the point I'm making, and where a keyed chuck scores. As long as one is aware of the danger, a keyed chuck can be tghtened enough just to grip a diameter without damaging it. There's no fear of it tightening if the part does start to slip. Obviously though if it is being gripped very lightly one would treat the part accordingly.
Mine are all Jacobs. I do have a couple of keyless chucks, one is a Rohm I think, but I've never used them. Came with a job lot IIRC.
Albrecht make very
The only collets I use are those that came with a pair of Autolock chucks. And the only time I need concentricity is sometimes with a lathe job. Even collets can't give the sort of accuracy that one can obtain by using an independant 4 jaw chuck and clock or DTI.
Going back to the OP's question though, I still think a better result is obtained using a wire brush on a bench grinder. I've used bench drills to remove the worst of the crud from valve stems, then finished them of with a brush on the bench grinder. It results in a smooth glazed crudfree finish. Ideal IMO. I dont think using any abrasive like emery cloth is a good idea. Mike.
Slippings the really good way to chew something up though.
That's a bit tedious for mounting a slot cutter though :-)
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