I got an email...
from Ron of Chicago. He brings up a very valid discussion we all face with every classic engine. I hope he doesn't mind me sharing this with you:
"I just wanted to drop you a line and tell you what a great graphic that was showing the sludge that is in an engine when you take out the freeze plugs. I would like to copy these photos if it's all right with you. I work on classics for a living and it's great to show people what can be happening inside their engine.
If not I understand
Of course I gave him permission, and I offered the larger pics if he needs them.
For many years, we have known the affects of old (or no) antifreeze in our blocks and we think things are ok inside because it did't freeze. What about the water pump lubricant or the anti-corrosion properties? Some folks don't believe it when told what's really going on inside their engine. When our engines left the factory they were all capable of cruising across the Mojave desert. Now, these same engines need seven-blade fans and shrouds just so we can 'live with' the temp gage as it rests on "p". Why? Brass 1-3/4" core plugs are cheap.
The only time anyone pulls their core plugs is when one leaks, and we're all guilty of keeping old antifreeze in our blocks way passed the 'anti corrosion' stage. (The same can be said for brake fluid, too.)
Engine coolant (antifreeze) contains phosphoric acid which disolves rust (it's in Coca-Cola and other sodas, too). Acid can only eat so much until the anti-corrosion properties are neutralized, but the 'antifreeze' part still works just fine. That stuff folks buy for winterizing their RV's plumbing only costs about $4.50/gal., because it is only antifreeze.
So, engine corrosion and electrolysis continue even though the hydrometer shows "good" when mechanics test the coolant. That's only a small part of this story.
Radiator and heater cores need phosphoric acid to clear passages of lime buildup. If yours is plugged, you can heat up some CLR (calcium-lime-rust) which removes all the nastiness because it contains a strong concentration of phosphoric acid. I use a small drill motor pump and a metal bucket (with a heater under the bucket) to recirculate the solution through my heater core or radiator. The bucket will show huge chunks as they dislodge. Then I run the flow the other way.
My latest project:
CLICK HERE to see my custom hydraulic roller 390 FE build.
"We've got to pause and ask ourselves: How much clean air do we need?"