DIY Cleaning Piston Tops

[smestas]

I'm currently in the process of replacing my lower head studs since I had a broken one and currently my motor is disassembled. I am not going to split the case as my car was running quite strong with 130,000 miles and I am operating on a limited budget. I removed the pistons in the cylinders as recommended since I believe them to be Alusil and they are going to be reused. I was wondering is there a DIY way to remove the carbon or clean the tops of the pistons without removing them from the cylinders. I’m thinking some solvent and some sort of cleaning brush.

Is this a good/bad idea?

[ChrisBennet]

Once the carbon gets wet it seems to soften. Maybe you could let them sit with some hot soapy water on them and then scrub them with a vegetable brush? I'd put a little vaseline around the top edge of the piston to keep the water from leaking out while they soaked. Brake kleen them off when you are done.
-Chris

[smestas]

Chris,

Thanks for the reply.

I'll give it a shot and see what happens.

Regards,

[Langers]

There are two methods for this: mechanical and chemical. I'm sure you can figure out the chemical for yourself, just use a strong solvent and a wire brush. The mechanical method involves using a wire wheel on a bench grinder to remove the carbon. It should not cause any damage to the piston as long as you stay away from the ring lands.

[smestas]

Thanks Langers,

I think Im going to start with water and if that doesnt do it Im going to bring in the big guns and use solvent. I was really concerned if this all would be OK while the pistons are still sitting in the cylinders.

[Langers]

Originally posted by smestas
Thanks Langers,

I think Im going to start with water and if that doesnt do it Im going to bring in the big guns and use solvent. I was really concerned if this all would be OK while the pistons are still sitting in the cylinders.

Woops didn't read the part about the pistons still being in the cylinders. You may have to devise some sort of system (using a vacuum cleaner maybe?)to try and keep the very small pieces of carbon getting between the piston and cylinder and scuffing the cylinder wall upon startup.

[jriera]

Simon, follow this thread --> de-carboning with water --> De-carboning with water...

I hope it helps.

[stevef]

Just did my pistons last night. Dropped then upside down in a tin can of kerosene (poor mans parts cleaner). Let tham soak for 30 mins and scrubbed the tops with scotchbrite. Finished off with 320 wet and dry. They came out really nice.

[ChrisBennet]

I'm probably as guilty as the next guy when it comes to this, but it might be a good idea to read the question a little closer before answering.
-Chris

[stevef]

Yeh, I realize the pistons are still on the engine but I wanted to share the Kerosene, scotchbrite, wet and dry method. Thanks

[snowman]

Be sure to check the side clearence in the rings. Simple to do with a feeler guage. Should be less than 0.004". If its a lot more, like 0.008" I would seriously reconsider reusing the pistons.

With this many miles on the engine you will have a great deal of trouble getting, keeping the ring grooves clean. The carbon from the piston tops is very difficult to keep out of grooves with the rings left in, and removing rings with this many miles is porbably not a good idea. YOu may need some real good luck to have it come out running like it used to.

Personally I would recommend removing and completely cleaning the pistons, use new rings, and have the cylinders honed using a ball hone to prep them for the new rings. Rings are relatively inexpensive.