lol...I had a garden hose clamped into the lower radiator hose and had the water flow throttle to 'just enough'. I run engines like this all the time. It only works with the t-stat removed, otherwise you just pressurize the block and blow the hoses off. I have a radiator for this truck, it just wasn't installed at the time because I didn't have the correct water pump drive pulley. The water pump, water pump pulley, t-stat housing and radiator were all missing from it when I got it. I just scrounged enough junk together to get it to a point where I could run it for awhile. That fuel bottle was hanging from some wire. I was able to pull it clear of the hood far enough to keep re-filling it. I have been using that same setup for this type of [censored] for years and years. It's an old Gatorade bottle with a metal tire valve stem bolted through the bottom of it. Works great and never overcomes a needle and seat valve.

1950 4100 - unrestored and driven weekly for almost no reason at all.