12 replies to this topic

[maieth]

...clean this up?



I've had my block, crank and camshaft professionally cleaned and they all look great. The pistons have been dipped too but the guy getting the work done didn't want to strip the pistons down so they haven't had the full cleaning (no problem here, job was a huge favour).
How can I now clean up the surfaces to remove all the burnt on coke without damaging the piston?

[ANON]

Ultra sonic cleaner or blasting.

[maieth]

Ultra sonic cleaner or blasting.

Preferably in my garage without having to send more parts away to someone else ;)

[OfMini&Men]

I used Brake and clutch cleaner and wire wool :)

[dow62]

Garage where i go use Wurth brake cleaner, for cleaning everything.

[ACDodd]

Before you waste time and effort cleaning them, measure the ring groove side clearance. If it is more than 0.004" scrap them and fit new pistons in fresh bores. If they are under the limit they are fit to be re-ringed as long as there is no excessive play in the wrist pin.

Ac

[maieth]

How do I go about checking that Mr Dodd?
They should be ok, everything that's come out has been in fantastic condition and the bores haven't even needed honing there's so little wear, but probably worth checking all the same. Will be borrowing a micrometer next week, or have feeler gauges, what do I need to do?

[ACDodd]

See video on how its done.



YOU MUST HONE THE BORES if you fit new rings or they won't bed in.

AC

[ACDodd]

Clean pistons by hand, and use a kitchen scourer (green one) to remove residue. You can scape the carbon off first but you need to be careful not to damage the piston.

AC

[antcole]

If you strip the pistons, get a washing up bowl and fill it with water and hoy in tons of biological washing powder, give it a good mix to dissolve it all and leave the pistons in the mixture for a couple of hours.
Give the mix a stir every so often and brush the pistons with a paint brush occaisionally.

The burnt on residues will fall away and it will also break down the carbon with very little effort.

I used this method to clean up the turbine and compressor wheels on a big napier turbocharger once.... the engine was running on crude oil and the washing powder mix just lifted all the seriously burnt on deposits right off.

[maieth]

Cheers for advice so far guys. Tried the ring groove clearances and they're good. Took block to machine shop for honing today, will start getting pistons cleaned up soon.

[maieth]

Piston #1 after a good soak in washing solution and a good rinse. That was a great tip Antcole!



Brake cleaner and scouring pad next...

[maieth]

And after brake cleaner.
New rings next then.