dklistul

Well, as I said above, I don't know the history of the block other than that it was opened at one time (the backwards #5 piston is the evidence for that). So I also have NO way of knowing what sort of coolant they ran.

I drove it another 20 miles this morning. Temp gauge stayed right in the middle. That makes more than 40 miles without the overheating issue. Earlier, I couldn't get 15 miles before it would threaten to boil over.

Apparently, the radiator is very marginal and ANY blockage reduces its heat transfer capacity to just a bit below what the engine delivers. I think the screen I installed in the upper radiator hose is keeping the crud out of the radiator tubes.

This afternoon when I'm done working, I'm going to pull the hose and check the screen I put in there. That should tell me how much debris I'm still getting out of the block and heads.

jlg2002

I think you're getting there. You may wan to consider having the radiator rodded out to make sure the tubes aren't blocked.

kenash

Hi,
I thinking it might have to re-boiled, as he had it "rodded" previously. See his opening comments.

bradleyb

for persistant crud issues, use a gayno filter in the upper rad hose - easy to clean and they have clear ones - will keep crud from rad

bradleyb

northern retrofit aluminum rad from summit works wonders for $269 and clean the gayno until it runs clear

dklistul

Right now, I'm running a piece of stainless steel screen stolen from a tea strainer. It fits nicely over the inlet neck on the radiator, and then I slide the hose over it and clamp it down. It works well to keep the crud outta the radiator but it doesn't have a whole lot of capacity (that is, not much screen area).

I ordered a see-through Gano screen today (they call it a "filter" but I hesitate to use that word on something that's really just a screen). Also, a couple quarts of Evap-O-Rust to run through the system after I install the new screen to try to get the last of the crap loosened up to get it outta there.

I know, I should just tear it down and do it right. But a rebuild isn't in the cards right now. Maybe next year. For now, I just want it to cool properly because everything else about the car works very well.