any one got some good tips on what to use and how to clean the crown of a piston....

 

put them in boil with petrol and use the edge of one of the old piston rings to scrap the crap off!

 

I would say that the pistons are still in block?

I usually use petrol/thinners and a scotch brite pad(scouring pad)
and then either hoover or blow out with compressed air

I,ve done this for years just make sure all debree is cleaned from around piston rings move pistons up and down and wipe with clean cloths

 

As above, i also get all the pistons half way down the bores, cover the top of the block with masking tape then cut out the masking tape from around the bores. Bring the piston you are working on (or pistons on a 4 cyl) to the top and put rags down the other bores to prevent crap gettin down.

The masking tape will prevent crap gettin in the water and oil gallaries and also the head bolt holes.

 

nah the pistons are out the engine at the mo, just wanna clean them up before refitting them

 

This is something i was going to ask shortly.

Hope you don't mind me butting in, but also anyone got any good tips for polishing valves?

 

Put them in the end of a drill mount in a vice and use wet and dry

and them a scotch brite pad bling bling

 

Either in a drill as mentioned above but be careful not to damage the stems. Or you can clean them up on a grinder with a wire wheel attachment.