How to clean engine parts covered with black burnt on oil??

[Adoom]

So I have a bunch of pistons, rods, caps etc...
They are pretty filthy with burnt on carbon.
I want to clean them to see if any are okay to reuse. 12 pistons/rods.
Degreasing them is easy.... but it doesn't remove the carbon and orange varnish stuff.

Since the pistons are aluminium, I cannot use anything alkaline like simple green or marine clean.
I have tried:
Hot water.
Super cheap degreaser cans. (and brushing with little nylon brush).
White spirits in paraffin spray gun. (brushing)
Kerosene (brushing)
Petrol.(brushing)
Gearbox oil (brushing).
Methylene Chloride. (soaking and brushing)
N-Methyl-2-pyrrolidone. (soaking then rinsing and brushing)

The last two are pretty bad, I'd rather use something else.

None of the methods I have tried get the pistons completely clean.

What do you use to get the burnt on stuff off?
Would diesel work?

I haven't even called the engine reconditioner to see what they would charge to clean the parts.
Since it's the weekend and they are closed, does anybody know what they would charge for cleaning an entire engine worth of parts?

[Townace]

Couple of cans of oven cleaner?

[fivebob]

Oven cleaner is often caustic and will damage aluminium.

You could try getting an old crockpot, put parts in and fill with undiluted propylene glycol antifreeze, enough to cover the parts, and leave it on high for a few days, then rinse and scrub the parts with a soft wire(brass) brush. Depending on how bad it is it may need a couple of treatments.

NB never use the crockpot for cooking afterwards, antifreeze isn't the best stuff to ingest.

The other option for cleaning carbon off pistons is steam. Also I've heard good things about Carbon Off but I don't know if anyone imports it here

[Makaveli]

http://www.enginerepairshop.com/cleanin ... parts.html

You can always call the local engine re-builder & ask for advice.

[Dell'Orto]

http://www.insinc.co.nz/webapps/p/78684 ... nleaf.html

This stuff here is one of the gruntiest degreasers I've ever used. I sat a set of 5K pistons in it overnight, and they came out like new. I didn't dilute it at all though, which is probably why it worked so well. Smells good too!

[Adoom]

http://www.insinc.co.nz/webapps/p/78684/149131/Bio-Clean-Degreaser-5Litres-Greenleaf.html

This stuff here is one of the gruntiest degreasers I've ever used. I sat a set of 5K pistons in it overnight, and they came out like new. I didn't dilute it at all though, which is probably why it worked so well. Smells good too!

How bad were those pistons? Just oily, or real burnt on stuff?

[Stott69]

Couple of 2.25L cokes?
What engine have you aquired with 12 pistons and rods?

[evil_si]

Go to a welding shop and get some aluminium acid, works great brush it on for 10-15mins and wash off in water with a dish brush or scotch brite

Tergo do a product called carbon off, We run it in one of our acid tanks, iirc $150 for 20litres

[Adoom]

Couple of 2.25L cokes?
What engine have you aquired with 12 pistons and rods?

Don't get too excited. It's more like two and a half engines. But I want to clean all the parts and use the best ones.

I've tried cleaning aluminium with coke before. I left it for a couple of days, there was no noticeable difference....

[Dell'Orto]

http://www.insinc.co.nz/webapps/p/78684/149131/Bio-Clean-Degreaser-5Litres-Greenleaf.html

This stuff here is one of the gruntiest degreasers I've ever used. I sat a set of 5K pistons in it overnight, and they came out like new. I didn't dilute it at all though, which is probably why it worked so well. Smells good too!

How bad were those pistons? Just oily, or real burnt on stuff?

Coked up massively, probably 200k worth of running. It only left small dots on the crowns, which came off easily with scotchbrite

[Adoom]

http://www.insinc.co.nz/webapps/p/78684/149131/Bio-Clean-Degreaser-5Litres-Greenleaf.html

This stuff here is one of the gruntiest degreasers I've ever used.

Do you know of anywhere that stocks it? Or do I have to order it online? I had a quick google but could not find any shops that sell it.

[JZCrazy]

May be Mitre 10 Mega has it, heading down that way shortly. I'll have a look see.

[KwS]

When i rebuilt the variable timing in my car everything was covered in baked on carbon from 20 years and 200,000KM of use. I ended up using a mixture of Wurth Brakeclean and Super cheap degreaser. Soaked the parts in it for a couple of minutes, scrubbed them with a stiff plastic brush and came up mint. Parts were aluminium too, didnt cause any issues.

[MrOizo]

Have heard Carbon Off is meant to be the bees knees!

http://discoveryproducts.com/products/carbon-off



http://www.youtube.com/watch?v=455g31uFsko

[Dell'Orto]

http://www.insinc.co.nz/webapps/p/78684/149131/Bio-Clean-Degreaser-5Litres-Greenleaf.html

This stuff here is one of the gruntiest degreasers I've ever used.

Do you know of anywhere that stocks it? Or do I have to order it online? I had a quick google but could not find any shops that sell it.

I bought mine from Bay Engineers Supplies

[Adoom]

I bought mine from Bay Engineers Supplies

$41. Out of stock in Lower Hutt, but they are getting me some overnight.

[Adoom]

So I got myself 5l of the Bio-clean that Dell'Orto recommended.
I chucked all of the pistons in a bucket and poured the Bio-clean in straight. Wow, after only a few minutes the varnish stuff inside the pistons just brushes right off!! And they smell AMAZING!
So I'm leaving them in there overnight.

[Dell'Orto]

It is good stuff, and also great if you have a cold

[jondee86]

There appear to be two similar products on that website...
This one... Bio-Clean Degreaser - Greenleaf (GE-Bioclean)


... and this one... Bio-Degreaser - Insinc (INS BD5)


Any particular reason for choosing one rather than the other ?

Cheers... jondee86

[Dell'Orto]

I used the former, purely as it was what was on the shelf at Bay Engineers