The Stovebolt Site Forums The Shop Area Engine Shop Cleaning water jackets

The 302 GMC sat in the hot tank for a week at the machine shop, still was looking pretty cruddy inside when ya looked through the freeze plug holes.Not so much rust but heavy mineral deposits,specially in the bottom rear left side.The shop said it could be chemically cleaned by a local company, about 80 bucks.
Ain't got 80 bucks to spare on this project,man, this GMC stuff is pricey,the parts guys weak ski masks. .
Since I had to drill the block for a full flow filter before the pistons come, I dragged it home,down the steps into Tony's shop of horrors.
Took an old plumbers snake,the cheap 1/4 inch spiral flex type, cut off 16 inches.Chucked it in a drill, fed it into a hole,engaged the drill motor.Lots of dusty stuff flying out the holes,good. Then I bent a few kinks in the snake,better yet lots more dust, and louder noise,spanking that crap right out of there.
The shop vac blew out the dust,looks pretty good.Drag it back to the shop,into the tank again.

If there's no rust prolly no biggy--Crappy water--wonder if that block is from the south? Lotta folks with old engines down here drain em and run water only in the summer--suppose to help with temp. Of course, if water is hard--calcifies everywhere--destroy a radiator in no time. I gotta water distiller here--waters so crappy get a teaspoon of minerals out of every single gallon--wouldn't drink tap water here or put it in my radiator either. If ya know somebody with a pressure blaster--might try it in each freeze plug--Ive seen a lotta crap come out that way.

How's the intake manufacturing project comin?

Get a gallon of phosphoric acid. Close the freeze plugs and the hole where the water pump sits.

Mix the acid with water until you have enough to fill the block (and the head later).

Let it sit over night.

The phosphoric acid ( the same stuff like in coke by the way) not only cleans out all the gunk it leaves a surface that prevents rost.

Drain the block and flush it with a garden hose or better a steam blaster for half an hour.

Do it outside or in a well vented room because it stinks awfull. Use glasses and wear gloves. The acid will not burn a hole in your hand but it is nasty stuff.

This is - by the way - the same thing what this company does for 80$.

Buzz,the engine came from the Kanas City area,was in an old church bus.Must have been a poor congregation, couldn't afford proper coolant The hot tank has a lye solution,pretty much takes care of rust,but not heavy mineral deposits,they need to be mechanically removed.A long screw driver poked down through coolant passage holes in the block deck helped loosen the mess too.
Stovebold,I've used phrosphoric acid before,also used Muriatic(sulfuric) acid to clean mineral deposits . The cleaning process mentioned by the machine shop is done by "baking" the block and seems to involve something more hi tech than acid alone.

We used to use tsp in solution to clean hot water heating boilers.
There is a followup treatment also to prepare the metal surfaces for corrosion resistance. This is rubber glove stuff, and the used solution should be properly disposed. Can you put the head on with an old gasket so you circulate the solution all the way through? The nozzles in the head are another area to look over very carefully.
When all this is over, will you use tap water to add new mineral deposits? No free lunch, that's for sure.

Truck: One of my many hats here at work is Boilers, if I lived closer we would boil that bad boy out. For home use, use something that removes scale, calcium, lime. THEN use tsp to flush then clean water to rinse.

Can't send you what I use here the Fed. Govt. would throw both you and I in jail! Ben

popcorn The Truth is Out There (Just take your time us guys on a budget have more of that then funds)