Cast iron block cleaning - what is current technology

[car4jim]

What is the current best practice for getting a block cleaned and prepped for rebuild?? It's been a couple of decades since I rebuilt an engine. Back in the day there was"hot-tanking" which I think has gone to the roadside due to EPA issues. I need to get my 1968 302 cast iron block cleaned. These blocks are rumored to shed rust and other contamination from the blocks cooling passages that can block the radiator. What is the current best practice for getting a block cleaned and prepped for rebuild. I live in So Cal if that makes a difference. Can anyone please point me in the right direction?

[rodneym]

Jim,
For California, the best you can do is some warm water with a little lemon.
I hope that helps.

[289ERAkit]

Drag it to your local car wash and use the outside high pressure sprayer. Bring a towel. Don't tell your wife about the towel....and throw the evidence away. The entire procedure could take up to a six pack maybe two if you bring a friend. Blow dry & sun dry the block asap.(If done via pickup truck....be sure to strap the sucker down).

[RICK LAKE]

car4jim Jim The best way is to goto a machinist and let them either boil the block or bake the block in an oven. If you can find a dealership mechanic with a Cuda machine, this will power wash the block with boiling solvent. It will clean 95% of all the crap out of the motor. The rest is with wire brushes and scrapping. Clean with simple green and warm water. Air dry and paint the block. all amchine surfaces like the cylinder walls spray with WD-40 and bag the motor to stay clean. Before cleaning you might want to run a tap through every hole in the block. This will get out the garage that ends up in the bottom of the holes. Good cleaning takes about 2-3 HOURS. Brush kit you can get from Jeg's or Summit. Rick L. Ps becareful where the waste water ends up.

[bobcowan]

Hot water, dawn dishwashing detergent, and some scrub brushes. The hard part is getting the cooling jacket clean.

[Dwight]

I took my block to a speed shop in Huntsville about 70 miles from my house a couple of months ago. At the time it was the only one I knew of. They wanted $40 to tank the block but it was not that dirt so I told them I would clean it myself.
When I got the block to my shop I found metal shaving inside of the block. I asked around and found two Old School machine shop just 40 miles North of me in Tenn. that could hot tank a block.

I took my block to one of them to hot tank clean for $45.

Ed's shop is like going back in time. Two cam grinding machines, head flow tester, Cam Doctor, everything to work on motors, any motor! One cylinder to large tractor motors. He does a lot of work for the local drag racers. I asked him how old he was and he responded 77. He started in a machine shop in 1955. He is old school.

Last week I took him a cam that I pulled from my GT 40 motor which I could not identify with the serial number on the end. He read the cam and printed out a spec sheet for $10. I learned a lot about cams that day.

I would check with shops that do machine work on motors. They will have a way to clean them.

[Bernica]

The pressure method on a turntable inside a cabinet seems to be pretty effective, as does hot-tanking. Regardless of which way you go, don't forget to remove the cam bearings first! I sent a block to a hot-tank shop years ago and asked that they press the bearings out first. They forgot, and it created quite a mess!

[Frank Messina]

Pull the freeze plugs then run a hook made from a coat hangar into the water jackets. You will dislodge a ton of rust and gunk. I use a shop vac to suck it all out.
Frank