Flushing rust from the engine

[IndyCuda]

I bought a '72 barracuda about 6 months ago. I recently pulled my 340 out for a cam swap and new paint. When I removed the radiator and hoses..you guessed it...the coolant looked 35 years old. After removing the water pump I see all kinds on rust inside the jackets. I found a thread on about a citrus product from Mercedes Benz they use to get rust and deposits out of the engine. They start with diluting a suds free degreaser like Shout. Then they flush, then use the citrus before flushing again. They say it works great. I also saw a post from naval guys where they use citrus on pipes in ships. Has anybody ever heard of anything like this? I plan on putting a nice aluminum radiator on in the spring and would love it if it did not have to circulate that stuff or is a regular flush ok and I am just being paranoid?

[72cudamaan]

You will want to flush the system for sure. Auto parts stores sell flush chemicals, but if your system is marginal at all these are likely to exaserbate the problem ( cause a leak).  One thought process is at least you will find the weak spot and can fix it before it strands you somewhere. The other thought is with a citrus cleaner you may not create a leak, hence no leak, no problem. my says to use the harsher cleaner and fix anything else before it does become a problem.

[Moparal]

engine out?   hard part is done.   Take it apart, pull all the freeze plugs and fittings, heads off, you can get down to the serious removal...and rear seal, fresh valve job n seals.   Go for it

[Aussie Challenger]

   While engine is out and freeze plugs out scrape out the rust and sand/dirt build up first, you will be suprised at how much build up there is. A good high pressure blast inside the core area will dislodge plenty before you use the chemicals.    
Make sure that you at least flush out the radiator as well.

[Bullitt-]

I was the one that posted this originally & your problem is that the motor is out & not running. All of the methods I've read about depends on heat & circulation so I don't know how they may work as a soak. I have casting sand in the lower parts & none of these methods deal with silca sand. Right now a I have Cascade dishwasher detergent in mine to degrease & plan on using Coka-Cola  as my acid. The cost of the Oxalic acid was going to be $20+ and from what I read works no better than cola. Then I plan on running a 10:1 molasses mix through to take care of the rust, then I will remove the freeze plugs & scrape out the sand.

[Aussie Challenger]

I have casting sand in the lower parts & none of these methods deal with silca sand. Then I plan on running a 10:1 molasses mix through to take care of the rust, then I will remove the freeze plugs & scrape out the sand.

  While engine is out and freeze plugs out scrape out the rust and sand/dirt build up first, you will be suprised at how much build up there is. A good high pressure blast inside the core area will dislodge plenty before you use the chemicals.    
Make sure that you at least flush out the radiator as well.

When you use molasses you will need to leave it in there for at least a week other wise it won't work. I used to use molasses to clean the rust off of my 1926 dodge 4 panels I was restoring many years ago.

[Topcat]

I did a re-build of a high torque Accel starter using Molasses. Put it together and tested it at a CSK store bench tester. It worked fine.

The links posted within aren't working anymore unfortunatly. It showed an engine being done in Molasses.

http://www.cuda-challenger.com/cc/index.php?topic=48206.0

Do it outside. It can get pretty nasty smelling. Keep it covered up well too. Critters will get attracted to the smell and want to go for a swim.

 If doing an engine block that's dis-assembled, you can buy a large quantity of powdered molasses at feed and grain stores.

[brianz426]

Are you having the engine rebuilt? If so wouldn't the hot tank process that most shops use take care of the rust?