Re: what about electrolysis?
They just don't make em like..... When I've had to replace radiators in the past on other vehicles I've gone to a radiator specialty shop that supplied all the auto repair shops in the area because I could buy a replacement that fit w/ the choices of core thickness(+capacity) & metal gauge (+ lifespan). The h.d. gauge units closer resembled the originals that came on the vehicle. My 87' 302 w/77k when I got it 2yrs ago, needed a new thermostat, and when I removed the thermostat I could see into the water jacket and saw that a fairly thick crust of mineral deposits baked onto inner surfaces at least .045 thick. This helped explain why I was haveing trouble advancing my timing very much. Working w/ boilers I'm aware of what that scale from city water feed does to their ability to thermal transfer capabilities. But the chemical treatment attacks & etches into the metal once it runs out of scale. With an engine using tap water the block will require this on scheduled basis in order to be able to effectively protect the engine especially in the reduction of combustion chamber temperatures &avoidance of pinging. But the radiator doesn't tolerate this well and it's life takes a little hit each time especially with a lot of the replacement units that don't seem to be that healthy to begin with. Then again, by not removeing this scale, the system ends up reaching higher operating temperatures which subjects it to a wider temp range of thermal expansions & contractions which reduces tensile strength and raises hell with creases, joints & seams. One of the attributes of anti-freeze is while its chemical properties are intact it acts as a suspension agent for the hard particals but riding the same thermal roller coaster, that's about the first of its attribute to go. Because I couldn't advance my timing past 12-13btdc I new I needed to descale the block whatever the cost to radiator life. So I used the prestone formula that's weaker but you add to radiator and drive around for a day before flushing witch it tolarated well and turned the scale deposits into a fine grained silt and after flushing, rather than to keep repeating the scenario I refilled w/ 50% antifreeze and 50% distilled water. Over a year I doubt if I've had to add a quart and at start up once it reaches oper. temp. it pretty much stays there. Anyway, the moral of the story is , if I were you I'd drain it and go 50/50 distilled to maintain the engine blocks thermal transfer capabilities and eliminate any need to introduce caustic chemicals that are detrimental to the radiator to keep the engine healthy. I also dumped a can of Seafoam in w/my oil & Transtune in my tranny fluid to desludge them, drained them both and replaced both w/ synthetic. Now I'm able to run .054 sidegapped plugs at 17btdc w/ 87 octane w/o a sign of ping. The radiator fluid looks the same as it did when when I first put it in after a year but I drain it and refill w/new every year anyway because it's like petroleum based tranny fluid in that appearance is no guarantee that its physical properties are still intact.