Cleaning flathead water jackets?

My shoebox starts overheating after 30 mintues or so of driving, so i dumped some rad flush in the radiator, flushed it all out, then dumped some drano in it and flushed it all out. Had water running crystal clear out of the rad drain ****, fired it up, took for a drive and it was still over heating. So i pulled off the heads and one the p***enger side the water jackets are plugged solid with mud. What is the best way to clean it out with out taking the entire motor apart and getting it tanked. It runs really good otherwise, no smoke, good compression so i dont really want to pull it all apart. Do you think sticking a pressure washer wand in the p***ages will work? any other tips or ideas?
Thanks

 

Buy several differant sizes of bottle brushes from McMaster-Carr or similar source. You can work them around the cylinders with a lot of effort and water to flush. I've often wanted to try the moll***as trick in a block too. But I'm afraid it might do TOO good of a job and make the core plugs leak. Anyone try it yet on a running engine?

 

whats the moll***es trick?? Never heard that one before.

 

Do a search on the board, it's 3 parts water to 1 part cattle feed moll***as. KILLS rust, same stuff as the Rustbeeter stuff at flea markets but way cheaper.

 

You can go as high as 6:1........

**** it takes time 4-5 weeks

 

Bluto, do you think it would work on a running engine? I've wanted to try it, just haven't had the need yet. I'm afraid it might make stuff leak that you don't want leaking, but it would get rid of the rust and ****.

 

Funny thing I was jus' thinking about that...... maybe we have someone here that would tell us what temp sugar crystals form an gum up the works when the cooling system cools

I kindda thing that's the drawback..... since you live in Choc town no one would notice the smell

 

I would throw a some Muratic acid in that engine.
Same as the vinegar clean but stronger.
Can be bought at hardware stores. Be careful with the stuff.
Throw a whole gallon in it and run the engine for a while.
A single acid run through may not do the trick. You may have to repeat it. Sounds like a really bad case of rust.
Clean your p***ages with a brush and high pressure first. throw the heads back on and then give it the acid treatment.
Lots of info on the Hamb about cleaning these engines.
When you are happy with it. be sure to rinse it well and throw in a neutralizer like baking soda.
Do a search.

 

Try a speedometer cable on a drill motor for the holes plugged on the deck and flush with a lot of water before you reinstall that head then install head and flush as Petejoe says.

 

Might want to try something like rustaid www.rustaid.com
that I think is oxalic acid. I used it at room temp on the aluminum
Clifford head on my flat 6 Hudson and for the most part it looked
like a brand new casting after 3-4 hrs. Whatever you use I'd test
on a small area first. I'm not a big fan of muratic acid(although I
buy it by the pallet for a commercial swimming pool) as even the vapors will attack any metal in the vicinity(not to mention your
lungs) Let us know what you come up with and how it works.
Pics would be cool.

 

Are you talking about the head p***ages or the block? Before you resort to anything drastic, I'd just get some long 1/4" - 3/8" steel rods and poke around thru the deck holes, flushing with warm water. The problem if you don't pull the engine is that there is a lip almost 3/4" at the water pumps that prevents really draining the cavity, made worse by the angle of the engine (sloped to back). High-pressure wash would work too, but would be REAL messy!

 

Years ago Prestone used to sell a heavy duty 2 part acid radiator flush. A powdered acid was added to clean water, run for an hour or so and then flushed. The thing that I remember is that they supplied a second powder to be used after the acid was drained and flushed. A neutralizer that killed the affect of the acid. You refilled the system and ran it for a while with the neutralizer. The neutralizer made me think it was pretty strong stuff. The EPA has probably outlawed this stuff today.

The neutralizing step may or may not be important but if I were using an acid I'd check into a neutralizer to stop the acidic action. A weak acid solution could damage soft metals over a period of time. Just something to think about.



I will soon be doing the same thing. I'd like to use the acid but I'd like to use a neutralizer after it. Anyone have any ideas what to use as neutralizer?

 

Phosporic acid will work on the rust but not eat up the metal it mite attck aluminum tho after any acid treatments use baking soda dissolved in a water solution to nuetralize everything
Ken

 

Baking Soda = Neutralizer.
oops... posted at same time.

 

use a piece of 1/4 " rod with a point on the end and a slight curve .poke it down in the water jacket and dig the crud loose. might have to use a hammer to chisel it if its hard. remove the pumps to flush the junk out.

 

I used M/H2O in an old truck that had rusted the pump shut

The cool thing is that you flush it with water an there is no acid to worry about...... won't screw up alunimum or warerpumps. The question is can you drive around with it in the motor?

 

Thanks I should have remembered that from the battery cleaning trick. DOH!

 

This wont help the plugged holes but its another tip. Get one of those telescopic rods with a magnet on the end. Used for hard to reach dropped screws etc.
I ran one back in my water p***age on my 49 when replacing the pumps and I got two small palm fulls of steel crud out of my block.

 

I have used ant poison, it's made of boric acid check the lable for percentage. More is better. Basicly it's the same stuff in radiator flush. Just much cheaper.
I have also used CLR in the coolant, they both seemed to work about the same to me....

 

Good advice on here. Without pulling the block, you're going to be limited on what you can get out though. If it's as bad as you say, I'd pop the heads, use the long rods as mentioned, jack up the rear of the car to get the angle working for you, block up the engine, pull the pumps & work really hard at digging, prodding, poking, & generally disturbing 60+ years of baked in mud.

If it's rust, I'd fill the entire cooling system with vinegar & run it a week or so. Drain, flush multiple times, neutralize with lots of baking powder, flush a few more times, & see how it does.

 

I don't think a flathead has any core plugs. The casting sand was removed through the water pump holes.

 

Here is the flatdog method,Take a e-brake cable chuck it up in a low speed drill and go at any water jacket holes you can fine.It don't hurt to let the end flair out like a roter-roter thing.After this treatment do same with speedo cable.Flush with lots of water.