4 replies to this topic

[maccers]

Hi all, I’ve got the head and s/charger off the engine block for a once over, and wandered if there is any value in cleaning up the carbon build up on the top of the pistons? 
 

what would be the best method and chemical to use if it’s worth doing?

[Homersimpson]

Hi all, I’ve got the head and s/charger off the engine block for a once over, and wandered if there is any value in cleaning up the carbon build up on the top of the pistons? 
 

what would be the best method and chemical to use if it’s worth doing?

If there is much of a build up then yes but if its just a colouring on top of the pistons I wouldn't bother.

 

I used to start with a rag and some petrol and then if it needed more than this move to a brass scraper.  Be careful not to push any of the carbon down the sides of the piston and use an air line to blow it all out when your finished.

[Bobbins]

Mask off all holes in the block face as well and overlap masking tape over the bore edge to the edge of the piston.

I remember someone many years ago cleaning the piston tops with a wire brush in a drill and nothing protected ... no the engine didn't last long afterwards and snapped a con-rod!

[maccers]

Thanks all, they are dished pistons if it helps/matters..?

 

Assume I can turn the engine to get each one at the top with the pushrods out? It’s a 1275cc based without the back plates..

[andyapanel]

Use a piece of wood to gently scrape it off and leave it untouched round the perimeter. Proceed gently.

As mentioned, twists of paper down all those holes in the block.

You can jack the front end up, put it in gear and rotate the wheels; the pistons will move to where you want them.

 

In the past, I have always found a blown head gasket is the best way to clean at least some of the pistons.