I'm part way through my engine re-build. I have had the head cleaned but there is a lot of carbon on the valves. I have left them soaking in some degreaser over night but that didn't really help.
Someone told me I can shot blast them. Is this a good idea or will it damage the vales?

Alluminium oxide or soda might be kinder to the valves - I think shot is a bit too harsh and you will peen the mating surfaces - in any case you will need to grinf them in again to be sure.

pillar drill and some emmery cloth did it for mine.

Valve stem held in a peice of fuel pipe to stop the chuck marking the valve.

regards

agriv8

What about some oven pride?

oven cleaner is supposed to be good for carbon.

not so sure what it might do to aluminium though.

I have always used a scaper on them followed by a wire wheel. Use the edge of the scraper to tap the carbon if it's thick and often it'll crack off fairly cleanly, then scrape the rest and finally wire brush.

I know this thread is dead, but Cillit Bang Oven Cleaner is no use for this at all.

Just tried it over night.