like the title says..have a b18a bare block and its filthy..

what should I use and how should I go about using it?

 

brake clean

 

93 octane works too. might have to soak it in it but it works like a charm. ive done it many a time.

 

*misread the block you want cleaned up

Hot tank is a no due to it being aluminum

The machine shop can do something called a jet wash

 

cleaning the top of some b16 pistons... should I do the same? they have like black build up on top..not much but can I do that with the pistons too?

 

Drop it in a vat of ATF. That or hot tank it

 

+1 best way to go

 

+2

 

Wear gloves, face mask, PROTECT YOURSELF from the
water/cleaner mix. Don't get the mix on you!

Remove all aluminum, copper,....anything thats not steel/cast iron
from the block. Remove any plugs and fittings. Attach a balanced chain to lower, and get the block out with, later on......so you don't get wet, and don't get anything on you, and don't knock over the drum.

Cover the block with water in a good metal drum,
carefully dump in caustic soda, or lye or maybe drano,
but not all three, heat the water until boiling, if needed.
Heating will take a while with so much to heat. Open fire works
pretty good, with the barrel up off the ground with concrete blocks
at sides/edges of barrel.

Filling the barrel with boiling water from the tap will speed the heating,
but fill barrel BEFORE dumping in the chemicals.

Wear gloves, face mask, PROTECT YOURSELF from the
water/cleaner mix. Don't get the mix on you!

Hoist the block out with the chain when sufficiently boiled.-Bob

 

that would work but b series blocks are aluminum