[Ziggster]

Decided to try cleaning out some of the coolant passages. I blew some of them out when the engine was still sitting on my trailer with the one head removed, but had to stop because the cloud of rust was so bad. There was an incredible amount of rust in the rear PS large coolant port/passage. I probably pulled out a total of 30-40 lumps with my magnetic extension pickup tool in this port, and about 15-20 on the DS port. I used a couple of large slot screwdrivers to scrap the internal passages as best as I could. Also used a short piece of coat hanger. There was significantly less rust in front passages on both the PS and DS sides, and no real difference between these two sides.
I’m sure it’s been discussed thousands of times as it concerns overheating issues with these engines, but it is imperative that candidates for rebuild be cleaned from all the rust inside the block. On my previous flathead, the machine shop did not have the fancy equipment to do a really thorough job, and I did some remedial cleaning after I got the block back.