Flush out motor with new radiator ?

What is the forum's recommendation to flush a motor that has not had cooling water for 10 yrs? I have now had the radiator re-cored but am concerned the new core will clog up. What product should I use & should I connect a temporary radiator & run the motor to heat up? (have pic but can't work out how to insert)

http://www.shutterfly.com/lightbox/view.sfly?fid=19743aee189a235dcf4ab00f16ca9e1e

Hi Stuart -

My Morris JB Van had a blocked cooling system when I bought it. I removed the head, which required a recondition anyway, and the radiator, which required a recore. I removed the water pump and drain tap, and set up a 10 litre urn beside the van for a constant supply of boiling water.

Then it was a matter of pouring boiling water into the water galleries from the top, and poking a piece of #8 fencing wire into the galleries to clear them. I started from the one over the drain, to get a flow happening, then worked away from there.

It took about 30 litres of water and 5 hours, but the cooling system came out as clean as a whistle, with no fear of passing the crud through the clean head or new radiator core. I now use Penrite Classic Car Coolant to keep the coolant in good condition.

Cheers - Bugly

Hi Stuart,
Here's the link to the 'How-To' of posting photos

hcvc.com.au/forum/YaBB.pl?num=1170808619

Thanks Bugly - but did you use anything besides the hot water to remove rust ?

Thanks also VKU3AO - pic now added ??

Here's a suggestion that is 100% effective, but entails some work. Obtain a 20-60 polyethylene drum or a clean 60 litre oil drum. Cut the top out, or part of the top (using an air chisel, or hammer and chisel on the oil drum - NOT a gas axe, unless you want to kill yourself!).

For the oil drum, obtain an offcut of exhaust tubing that is approximately the same size as the bottom inlet of the motor. Cut a hole near the bottom of the oil drum, that's the same size as the exhaust tubing. Braze the length of exhaust tubing into the hole, ensuring it's water tight. Connect a length of the corrugated, bendy radiator hose between the bottom inlet and the exhaust tubing. You'll need a stand for the drum. Milk crates and lengths of wood work, but a fabricated stand of the correct height is better ..
Connect another length of hose to the engine outlet and drop it into the top of the drum.

For a poly drum, you can use nylon or poly tap fittings to make a bottom outlet.

Fill the drum and the cooling system with a 5%-10% solution of citric acid. You can buy citric acid granules from food wholesalers, it's a food additive used in bread and a food preservative. It's 100% safe.
Alternatively, you can make your own, by using rotten citrus fruit (oranges, lemons, mandarins), and by throwing the fruit into a big drum, and adding water. This takes about 3 weeks, and the result is a little "pongy" .. but it works. You decant and use the liquid and dispose of the remaining fruit solids.

The citric acid doesn't need to be heated to work, but it needs to be circulated. A couple of days should see a vast improvement in the cooling system condition. The beauty of citric acid is that kids can dabble in it, if you have kids that are into everything, and it won't hurt them.
The citric acid will not affect the base metal, nor will it affect alloys such as aluminium alloys, brass, or magnesium alloys, nor copper.

You can use cleaning solutions of 3%-5% caustic soda or 3-5% hydrochloric acid, which are quicker-acting .. but these are dangerous, particularly if you have kids around. Hydrochloric acid gives off chlorine fumes and must be well ventilated.
Caustic soda can cause severe burns .. so caustic soda and hydrochloric acid both require isolation, safety gear, such as acid-proof gloves, eye protection, and protective clothing. It's wise to use gloves with Citric acid, it can affect the skin of sensitive people .. but overall, it's very safe.

Hydrochloric acid will eat the base metal as well as the rust, but you can slow it down by adding household detergent (this also works to release clay deposits in the rust and scale). Caustic soda will eat aluminium and all its alloys.

Here's some pics I took of a Cadillac manifold that I acid-bathed in citric acid. This engine had been out in the weather for nearly 40 years ..
The two top pics are the "before" pics .. and the bottom two pics, are after 3 days in the acid bath, and after being hit with a cheap little single phase, 1500 psi pressure cleaner ..

If you drain the citric acid after several days .. and then poke a pressure cleaner hose into the inlet and outlet of the motor .. you'll get out all the loosened and dissolved crap, and the inside of the block should resemble the bottom pics ..

Thanks onetrack - that looks the way to go - nice clean job - I will rig up a small electric pump to keep solution circulating (won't run motor). I have used 10% solution of molasses to disolve rust in the past, but your citric acid doesn't seem to leave a coating on the surface like molasses!

Stuart,
That's all good advice and to make sure no rust flakes get into the radiator core, for the initial runs put a foot from a pair of pantyhose into the inlet pipe of the radiator, held by the rubber hose over the steel inlet pipe.Clean it out frequently and you will be amazed how much rubbish you get from it. Don't need to keep it in there for long.
Murray

If you are not running the motor but using an electric pump would it be worth using a drum to circulate the water in and out of?

That way you can keep the dirty water out of the radiator and it can't get blocked. It is also easy to see if the water is getting too dirty

hmmm have to give the lemons a go myself,been using molasses ,and one day the neighbours will work out where that smell comes from!! also its not good for cast and alloys!! data plates gone! :'(

Hi Stuart -

No, I used nothing but the boiling water. There was a bit of scale in the block, but the poking and prodding with the #8 wire broke it up and it flushed out with the water. It was amazing the amount of solidified crud that was in the block. Hey Onetrack, judging by the photos the citric acid trick sure looks like a winner!

An engine shop would have used a hydrochloric acid bath, (in fact the head was acid-bathed when it was reconditioned at the same time I cleaned out the block) but I wanted to stay away from the acids.

Cheers - Bugly