Cleaning coolant passages...in car

[64rocksprite]

Okay folks..
Once again, my poor storage practices many moons ago have cropped up /bcforum/images/%%GRAEMLIN_URL%%/wall.gif .
The cylinder head and water passages around the pistons are badly corroded, with chunks of rust visible. I've cleaned all I can reach, but that is not much.
Before replacing the water pump, I filled the engine block with a mild acid, let it sit for about an hour and then flushed with the garden hose. Lots of rusty water and some flakes came out.
Problem is..I have a newly re-cored radiator..I dont want to install it when surely more of this crud is going to come loose the first time the engine is up to operating temperature.
Anyone have any ideas on cleaning it SHORT of taking the block out and having it hot-tanked?
I thought about rigging up a 'temp' tank reservoir (bypass the radiator completely) that I could run hoses to and circulate a cleaning solution with the engine running to get it nice and warm. (?)
Open to suggestions!!!
Last one for tonight..this is a 64 MK II (downflow). I had always assumed that hot engine water exited the cylinder head at the thermostat housing, thru the rad, then returned at the bottom hose..is this right or do I have it backwards? Looking at the water pump, seems like it might go the other way..I'm going to install a elec fan..and want to get the sensor at the inlet. I would imagine the stock temp bung is at the hottest point, after the t-stat.
THANKS ALL!!
Devin

 

[aeronca65t]

There is some additional ideas about this subject that were just posted on our Mini forum here at BCF

~CLICK HERE~ to see them.

 

[JPSmit]

Disclaimer - I have never tried this and accept no responsibility BUT - seems to me I have heard of putting some pantihose as a filter to catch the crud before it enters the rad. FWIW

 

[JerryB]

""""""is this right or do I have it backwards? """""

your right.

What I wud do is remove the small plate on the back of the head and the heater valve.....remove the thermostat housing, and also the petcock or plug on drivers left rear of the block. run a lot of clean water thru the case....


You can also bypass the rad. ...... use a piece of tubing to join the two radiator hoses and fill the motor at the thermo housing.....run the motor till the water is warm then go back to the above paragraph.

BUT....there still will be some pieces of scale that will work there way thru the system when you start putting some miles on the car which will end up in the botom of the block and the rad.

""""""""""""The cylinder head and water passages around the pistons are badly corroded, with chunks of rust visible"""""

BUT....it might be too far gone ?

 

[AweMan]

Here is a link where you can purchase Phosphoric acid Industrial grade.
https://coasty.com/phosphoric_acid_industry.html

Uses

Metal Finishing
Phosphatizing compounds for rustproofing and improvement of paint bonding of steel; as the major ingredient in solutions used for the chemical and electro-chemical polishing of aluminum, stainless steel, and copper alloys; and in metal cleaning and pickling.
Chemical Manufacture Production of phosphate salts.
Equipments Maintenance Descaling of boilers and heat exchanger tubes.
Ceramics and Glass For ceramic colors chemically-bonded fire brick for steel furnaces;
Petroleum - Polymerization of propylene; alkylating catalyst.
Plastics As catalyst to speed up setting action of some synthetic resins.

 

[Keoke]

Coca Cola Hits the spot and will remove the ROT!---Fwiw---Keoke- /bcforum/images/%%GRAEMLIN_URL%%/grin.gif
\

--Ops, Sorry my error this is not an in car technique used in stripped blocks only.

 

[Sarastro]

With all the sugar in it, I don't think it would be good to put Coca Cola in your engine for rust removal. It only works because it contains a small amount of phosporic acid, plus a wee bit of carbonic acid from the carbonation.

Any acid will remove rust--the nice thing about phosphoric acid is that (1) it attacks the iron only slowly, converting it to iron phosphate, but (2) attacks the rust much faster, converting it also to iron phosphate. So, I think it makes more sense than, say hydrochloric acid (AKA muriatic acid) which attacks the iron much more vigorously.

Problem here is that you need some way to monitor the whole process, and make sure you are removing all the rust but not damaging the metal any more than necessary. Not sure how you would do this, since you can't look into the block and watch the process take place. Then, as JerryB suggests, you'll never get every last rust flake out, so you need to be prepared for a lot of little pieces circulating, and maybe even some bigger pieces that didn't come off on the first try. But, I suspect, if you do a really good job of flushing the block, the remaining bits might be small enough that they don't cause much trouble.

Sorry, I know this is a lot of speculation, but these are the issues I'd think about if I were doing this.

 

[tony barnhill]

Is there a way to remove one of the freeze plugs near the rear of the block to install one of those backflush kits? Then, you could force high pressure water through the block & out the opening where the water pump will go.

 

[jlaird]

Shoot guys lets not make a big deal of this. Flush it well, drive it till good and hot, flush again, drive again, flush again.

Call it done for a month or so. and do it again.

 

[Keoke]

Some good speculation. However, sugar desolves in water and can be flushed out-ROT does not!--Keoke

 

[jlaird]

Yea I agree Keoke, a bit of coke would be fine of course.

 

[Keoke]

Yes Jack, some of the available radiator flushes will do just that, then a good commercial back flush will clear most of the rest.---Keoke

 

[AweMan]

Phosphoric acid would take an extended time frame to do much damage to the "Good" Metal in the block & head. You may end up changing the freeze plugs tho, {with the amount of rust you are telling us, I`m almost sure you`ll need to anyway.}
Another alternative is caustic soda, you used to be able to buy a "kit" at most any auto parts supply {It`s been a long time sence I`v used one of these kits so I can`t say if they are still available, the way the E.P.A. is these days.} This treatment would require running the engine for a few days {normal driving} with part one in the cooling system. Then you drain and add part two {the nutraliser} and run it for a few days. Then you drain and flush and repeat as necessary until you get clear water. Again, if the freeze plugs are rusted they possibly will begin leaking. replacing them after any kind of severe rust treatment is almost a must. you say you have an old radiator? Put it on and give it a go.

 

[64rocksprite]

Hey, thanks everyone! I posted this and then had some extended meetings..haven't checked back until today.
So I think I have a direction..I only allowed the previous acid flush to sit for about 15 mins...(I know, not long enough) I was a bit scared to let it sit longer...and I wanted to see how much crud came out. I may have given the impression of the passages being REALLY bad, water seems to flow quite freely through the system. I think a longer mild acid flush with the block warm will do the trick to remove the 'clingers' I think it might be more precipitates than actual rust. I will try to scape a bit off and do a small 'bench test' to see how the sample dissolves (or doesn't!)
My gas tank is still at the radiator shop being hot tanked or at least I hope it will be soon so I can get the car running again.

I am a bit worried about using only a hose to bypass the rad. I did this once for about 5 mins..and believe it or not, the system built some pressure..enough to make taking the hose off with a mild acid solution a scary proposition. I'm going to try to make an open bucket reservoir so I don't build pressure on a temp hose.
John-Peter--pantyhose!! perfect! I was trying to find a faucet strainer that I could somehow fit in the t-stat housing...but that might be a better idea.
JerryB - thanks for the clarification on the fluid path..thought so, but the more I looked at it..just confused me.
AweMan - I will check those products out or perhaps the "Green" stuff from Autozone.
Thanks to all..I will update you on how this went as soon as I get it done.
Appreciate all of your collective help!!
Devin