here's one I haven't seen..

new engine 460... rebuilt about two years ago... ran it to break it in and put it on the stand. Getting ready to add hoses and radiator and other 'start up' stuff.

I noticed that the hoses I used for break in showed a film of rust inside so I'm assuming the block is the same... would it be worth it to flush out the block before adding new hoses and pretty new alum radiator and antifreeze to keep everything clean from the get go ???

if so... just use Prestone block flush or is there something better to get it squeeky clean

edit... I'm not at a point to run the engine to heat it up... so ??? will a flush even make a difference on a cold engine ???


j

 

The best flushing agents are Sulfamic Acid and Cascade dishwashing detergent. They will remove any oily deposits too. Have used both in EMD engines, and they work very good. If you want to keep your cooling system squeaky clean from core sand, which keeps leaching out forever, install a coolant filter.

 

What proportions??

 

I had never heard of this acid before so I did a little digging:


Sulfamic acid is used as an acidic cleaning agent, sometimes pure or as a component of proprietary mixtures, typically for metals and ceramics. It is frequently used for removing rust and limescale, replacing the more volatile and irritating hydrochloric acid, which is however cheaper. It is often a component of household descaling agents, for example, Lime-A-Way Thick Gel contains up to 8% sulfamic acid and pH 2–2.2,[12] or detergents used for removal of limescale. When compared to most of the common strong mineral acids, sulfamic acid has desirable water descaling properties, low volatility, low toxicity. It forms water-soluble salts of calcium and ferric iron.
Importantly, sulfamic acid is preferable to use in household in comparison to hydrochloric acid for its intrinsic safety. If erroneously mixed with hypochlorite based products such as bleach, it does not form chlorine gas, where the most common acids would; the reaction (neutralization) with NH3, produces a salt as depicted in the section above.
It also finds applications in the industrial cleaning of dairy and brew-house equipment. Although it is considered less corrosive than hydrochloric acid, corrosion inhibitors are often added to commercial cleansers of which it is a component. Some of its domestic use, e.g. Easy-Off, for descaling include home coffee and espresso equipment and in denture cleaners.


I think that if I were going to try this on engine components I would do a bit of testing first with various concentrations to see what worked best. This is also used as an herbicide so I wouldn't drain it onto my lawn or any other growing plant that I wanted to keep alive.

 

Sorry, I don't know what the proportions would be for a small engine. The 16-710G's have a 300 gallon cooling system. But I can tell you that we used 15 boxes of Cascade followed by three clean water flushes.

 

Assuming you used 48 oz boxes that's 15 boxes at 48 oz or 720 oz total for 300 gallons or 2.4 oz per gallon.

 

Yeah, they were the big boxes. I don't recall the ratio we used for the acid wash though, but the system was squeaky clean. We also ran a quad coolant filter manifold and the cartridges were changed at each oil filter change of around 600 hours.

 

The big box is 125 oz the box sizes are 45 60 75 and 125 oz.

So there could be quite the variation in mix depending on box size.

 

household grade vinegar will do the same thing..........fyi

 

According to this rather cheesy video they used 8 oz by weight of sulfamic acid powder per gallon of water.


Now they were cleaning excess grout off tile but at least that gives you an idea of ratios.

 

They were the 60 oz. size I believe. You could buy them in a grocery store. I can't check the purchase order because I'm retired. There was an EMD "Pointers" letter describing the procedure and the doses, and I never saved a copy.

 

I've never been big on using chemicals in cooling systems, hate to possibly compromise head gaskets, water pump seals, etc. Best way to clean a block (even better than stripping and dipping) is using a flush gun. Air and water mixed together creates bubbles that slam into core sand and rust accumulations, knocking them loose and carrying them away. Basically just remove thermostat, hook up your garden hose and an air line and let 'er rip.

They're still available, this is one I've used for years, just shove the cone in a hose (disconnect engine from heater and radiator) :

You'd be surprised what comes out, even after the bare block has been tanked at the machine shop.

 

Nice, but core sand will leach out for many many years and hours/miles of service. That's why coolant filters, among other reasons. Head and other gaskets are inert and not harmed by automotive chemicals and mild acids. What you would be concerned about is the chemical interaction with aluminum parts and some O-rings.