Have spent the last week putting all the peripheral parts back on my now rebuilt 390. Engine painted with urethane. Every bolt and nut cleaned. Threads that need anti-seize, so I never have to deal with frozen bolts, got it. Used the Big Block Ford book to make sure nothing was missed. Been a long time, 24 years, since I started up a rebuilt engine and it always makes me nervous given my perfectionist ways.

So with the break in oil in the engine, straight water for cooling, primed the engine by spinning up the oil pump shaft for pressure and filled the fuel bowl. Decided to go with the book talking about running water into the radiator and drain some out at the same time to keep temps down on break in.

Sit in the truck, get the stop watch out, have my tach visible and hit the ignition. The engine starts right away and we are up to 1800-2000 rpm. Going fine with only light smoke initially. After about 8 minutes water flies out of the radiator cap like Old Faithful. Immediately shut the engine down and move out to take care of. This part the book is not right about. Put some water in, cap on and fan in front of radiator to continue break in but now it won't start.

Only tried twice for one one thousand two and could tell it wouldn't catch no matter how long I held the key. Check the distributor to see if wet but no problem. I know there is air, compression and spark but what about fuel. Pull the air cleaner off and the carb is soaking wet internally. The last time this happened was when the Mustang blew it's power valve, while driving one night, and I could barely get it home at which point it wouldn't start anymore. New power valve and all fine. Good thing I have spare power valves for tomorrow morning.

 

How bad did it flood? does the oil smell like gas? pulling the plugs will help dry it out too...
Sounds like your startup is right on otherwise. Don't forget to vary your rpm during cam break in.
Best of luck!

 

Took the carb off this morning and it was soaking wet still. Plugs were fine and in fact looked great on the grounding strap and first ring for timing and heat range. So went to my parts bins and pulled out a new power valve and also a new brass float to replace the 5 year old nitryl float. Helps to have a large supply of all the small parts in stock. Put some fuel in the bowl and shot some starter fluid down the carb and she started right away. Ran it 5 minutes before the temp got to a point where I wasn't comfortable and immediately shut it off. Will let it cool and run it again. Has a total of 11 minutes break in so far. Oil clean and no leaks of any kind.

 

Have you checked your timing to make sure you are good? Could be why your temp is rising.

 

Timing is between 6-10 but can always retard a little. New engines always produce a little more friction besides sitting still with no air blowing through the radiator.

 

I don't know if you put a thermostat in or not. A friend put mine in during assembly and put it in backwards and it took about 10 min to get hot and do what you described.