cleaning carbon deposits of pistons and valves.

[spookey]

Hi everyone. Today i finaly got around to having a look at my g40 engine after pulling it out of the car nearly a year ago.
I removed the head just to have a nosey at the pistons and bores and every thing seems to be in order but as you would expect there is carbon build up on the pistons and valves. I obviously want to remove all of this before i put it all back together. Idealy i dont want to remove the pistons from the block but i may take the valves out of the head (suspect valve stem seal leak) so does anyone sujest any product or way or doing this without damaging anything i have been sujested nitromers but it can eat away at steal and i dont want to damage my bores if i havnt cleaned it off quick enough.

any help appreciated

Thanks Luke   

[scotsjohn]

Piston to top of bore and power drill with brass brush. Vacuum round piston when finished then lower piston and wipe away anything on the bore wall. DO NOT USE ANYTHING LIKE NITROMORS-CONTAINS PHOSPHORIC ACID IIRC.

[Yoof]

Scotchbrite and petrol is as good/cheap as most stuff, just make sure that when you're done cleaning all oilways and rings etc are clean from deposits.

[Nick_S]

Nitromors, or at least the one in the green can doesn't contain phosphoric acid. Its a blend of methanol and dichloromethane, the DCM in there what gives it its kick Chlorinated solvents are the best degreasers and used by rolls royce on their titanium. i have a aerosol of Trike - trichloroethylene (old tipex thinners from way back in the day) which comes out for those stubborn occasions, but you can't get it in the shops anymore   Paint thinners will do the job well enough. Don't go near valve stem seals with chlorinated solvents though as these easily dissolve rubber and plastic!

[type-r-dunk]

Hi
Well I find alloy wheel cleaner works really well
Dunx

[randombadger69]

For the valves stick them in a drill and clean with scotchbrite and petrol, parrafin or diesel. Drill soon pisses through these!