All Small Six 223 Engine opinions

This relates to all small sixes


Top Poster
Staff member
Supporter 2021
Supporter 2019
Yeah you are in a very tough spot having so much rust and crude inside the blocks cooling jackets you could maybe use some Vinagur in the block and let it set for awhile to see if that will clean it out. On the heater core and radator try reseverse flushing them to see if you can get them unplugged. Best of luck


New member
Guys this thing is turning into a headache. So I removed the thermostat and used a water hose and rinsed loads of rust out of the engine cooling passages around the pistons. I mean more than can possibly be good. I put a magnet at where the thermostat was to catch the rust as I tried to flush it out. I flushed it back to front until I wasn't getting large particles anymore. This im sure is the reason it was over heating, which means my heater core and radiator are probably stuffed up. I'll probably install a magnet in that hose to catch anything else. I also ordered NOS head bolts for the second time, hopefully they arrive this time.

I intend to use copper coat on this gasket and loctite 592 on the through bolts (head bolts) I am probably going to use the holley carb on it until I decide whether or not it will run right (not over heat) and it I can pull that off, I'll probably put the Holley sniper on it. But it's a little pricey considering idk if the motor is gonna sort out yet.
Sounds like what i was dealing with. Mine was so rusty the water pump was seized, the truck ran before my grandfather parked it in the garage where it sat with no coolant for several years. If you haven’t already I would pull the water pump and check it. At this point I would send it out to be hot tanked they usually use a caustic solution that strips the paint and most rust. You can try a rust solution or rust converter but I don’t have any experience with it I’ve always had good luck with the machine shop cleaning it. If you are going to do it yourself maybe use a solution let it sit for a few days then flush it, may have to take the freeze plugs out. Good luck on which ever route you choose!


Active member
I use phosphoric acid to clean out gas tanks and remove rust from metal. It is not as aggressive as muriatic acid and won’t burn you if you get it on your hands. No nasty fumes either. The metal does not not need to be neutralized after soaking like other acids....leaves a protective coating without flash rusting. Brand name Evaporust is phosphoric acid as is CLR.....usually green in color.