The Stovebolt Site Forums The Shop Area Engine Shop I'm re-using my 040 pistons. What do I do...

The 261 block is back from the machine shop. It's been cleaned, decked, sleeved, honed and measured.

That motor had been rebuilt not long ago, so wear was minimal (A ring broke loose). The shop says I can re-use my pistons, just re-ring. I just received FRESH rings from Patrick's.

The pistons do have some mild carbon build-up, what should I do to them? Sand? Buff? Polish? Bead blast? Leave them alone?

I'd like them to look shiny as new...

Any tips? tricks? I'm all ears!

Thanks in advance guys,
whizzerick

whizzerick,

Being a foundry type, you are familiar with sand. It's sort of nasty stuff and not the thing you want in your new engine. If it were me, I would NOT bead blast or sand blast any piston.

Clean them with solvent and a soft wire brush. If there is tons of carbon on top, you can scrape it off with a putty knife, or do the oven cleaner routine.

The ring grooves have to be clean and carbon free. If the pistons have any drain holes in the oil ring groove they must be clean too.

Stuart

Stuart, the oven cleaner! Great idea!
Should I use a brass bristle brush or is something stiffer okay?

whizzerick,

I think the brass would be great, although I don't think you could actually hurt them with any wire brush used by hand.


Stuart

You can buy a ring groove cleaner at a tool store or break an old ring into & use it to clean the grooves. You must get all the carbon out of the grooves. It has built up as the rings wear & the new rings may not go far enough back in the groove.

I wouldn't use oven cleaner on aluminum, Sodium Hydroxide (lye) is a common oven cleaner ingredient and will disolve aluminum.

Works great on cast iron or steel though.

That's great info, guys. Thanks a lot...

Sitting here looking at this lump of iron, I cant help to grin... Opening boxes with shiny bearings... Gaskets...

Silly how a fresh engine can do that to you, huh?

Oven cleaner will eat into aluminum.

I'll be dipping the pistons in the recirculating parts cleaner, followed by a scrubbing with a brass bristle brush and a blast of compressed air...

Use a wire wheel with out applying much pressure will polish them right up. How did a ring break loose without damaging a piston or a cylinder?
Scott

if it was rebuilt not that long ago shouldn't be alot of carbon in the ring grooves but still needs cleaned i agree with wrenchbender a broken ring makes a good cleaning tool.

The procedure that is quick and easy for the piston tops is: take an old compression ring, turn it so that it's edge is on a 45 and use it as a scraper. That always does a good job. For the grooves, use the proper tool. You don't want any left over carbon in there.

It did! 3 cylinders had to be sleeved...
But we checked the pistons carefully and see NO damage... :confused:

One explanation is that the gouges where present BEFORE the last rebuild and they decided it wasnt that much of a problem?

[img]http://www.whizzerick.com/261/gouge.JPG[/img]