Removing carbon deposits from engine components

[UK Pete]

Does anyone know what safely dissolves carbon from pistons and valves,? i have googled it and it seems like there is nothing

[hairygit]

Caustic soda will, but it also dissolves aluminium, so do not even think of trying it! I'm afraid a small scraper (an old feeler gauge works well) is usually the best bet, get the worst of it off, then use a polish such as solvol to remove the last traces and leave a nice shiny finish that carbon won't stick to so easily in the future. Make sure you remove all trace of the solvol, it is abrasive and you don't want even tiny particles of it inside your rebuild

[UK Pete]

Yes i was hoping there is some sort of safe to use stuff but it seems not, what i wanted to do was get the valve stems and pistons totally carbon free, i dont want to scratch the valve stems up incase there is some sort of stellite coating or something similar, i suppose i could use the caustic soda on the valves and do the pistons manualy with scrapers, soda blasting is an option but the expense puts me off
Pete

[steff750]

  don't use caustic soda on valves either don't forget the head is alloy aswell hairy git is right there is nothing wrong with a bit of elbow grease so get scraping ,but if your as lazy as me  get a wire brush and a drill no problem it will even put a bit of a shine on things for you

[hairygit]

Certainly wouldn't use a wire brush, and definitely not on a drill A wire brush is far too aggressive on alloys such as pistons or cylinder heads Back in the days of iron heads and pistons a wire brush was perfect, but it will gouge alloy really badly, manually scraping it off is the safest way Probably not what you need with your arm recovering Pete, but safer. How is the arm doing?

[UK Pete]

Thanks for asking Hairygit the arm is recovering well i am riding bikes again, the physio for the frozen shoulder is working well and i have about 80% movement, but i would say only 50% strength, even less in some positions. on the whole quite a fast recovery they are telling me
As for the cleaning carbon off , i have used every method known to man over many years of engine building i am well aware of what to and what not to do , i was just hoping there was a miracle chemical  lazy mans method of getting the job done Ha Ha
pete

[hairygit]

Lazy CAN be expensive! You could always pay an engineering firm to do it or go mad and send it to be gasflowed, then it would come back with a mirror finish, and maybe a couple of extra horsepower as well, then the thinking gets really expensive you think "Hmm, gasflowed head would be even better with a big bore kit " Ball's in your court!
 

[simongi]

Hi

I have been using one of those orange fibre wheels in the end of the drill. Its not to aggressive and its quite quick. I put my drill in the vice and off you go. But please use goggles. Some might disagree on this method, but you can only try it yourself.
Good luck

[Tomb]

I find a Brillo Pad works best, not aggresive to the ali but rips through the carbon, and the soap in them helps clean things up an all, including your fingers

[the-chauffeur]

Pete

With all the tools at your disposal, I'd've thought you'd've set yourself up with some kind of soda blaster assembly - not exactly lazy, but it's about the best way I've found to get stuff properly clean without the worry of any bits being left behind.

One spray I've had limited success with (albeit that's more than others) is gasket remover.  It seems to shift a whole lot of stuff that solutions like brake or carb cleaner won't dent.

Good to hear you're on the mend.

[K2-K6]

Hey Pete, that sounds like decent progress with the arm and good to hear.

Think the basic problem with carbon is that it's fairly stable and inert to many things (and why it's so useful) so anything mild will be unlikely to do much.

You probably need to ask an organic chemist for any informed opinion.

Didn't people use to soak it in "Reddex" to soften it? don't know if its works though but the logic seems to be heading in the right direction.

[florence]

If you bury the cylinder head in the garden for a few months the metal starts to corrode under the carbon and it all flakes off.  Sorry, only joking, I find careful use of a scraper is best, a hard wooden one will often get most of it off but it does take a lot of hard work.

[LesterPiglet]

I've used one of those small wire brushes on a wheel without detrimental effect. The aren't stiff enough to gouge the alloy of the head. The valves can take almost anything.

[steff750]

lesterpiglett wrote

I've used one of those small wire brushes on a wheel without detrimental effect. The aren't stiff enough to gouge the alloy of the head. The valves can take almost anything.

  at last the cavalry have arrived thank you lester ,i have done this for donkey's years i ain't seen a hole in a head yet , or even a piston for that matter,this little" pearl of wisdom "was passed on to me from my old man, years ago they used to be called de-coke sets and not gasket sets for that reason ,because every so often you needed to de-coke the engine i will stick to the tried and tested methods.i was talking to a guy at a show last week who had just paid £280 to have his engine vapor blasted,now that's what i call lazy

[UK Pete]

yes i priced up getting my engine vapour blasted, including pistons , and it was £240, i offered £200 cash went away and thought about it and relised i have bought whole bikes for less, so i am not prepared to pay that,