Fired my flathead today for the first time!!!

[flthd31]

Originally Posted by Chris

Well, theres more to the story. Day after I fired it for the first time I lit it off again. It spit a shot of water out the passanger side header. Pulled the plugs on that side, shot water out the number 2 cylinder. Hmmmm....pulled the head and found a crack in the Edmunds head:

I had the heads milled and the cracks were not there. I torqued them to 30, then 50 in the right sequence so I do not know what caused the crack. My Dad had a magentis dial indicator and we ran the numbers on all 8 clinders to measure how far up they came above the deck...making sure the rod did not bend. It was fine

This event brings back some bad memories.
Years ago I had the similar thing happen to me. We did all the tests you did and determined that "all was fine" just as you did.
That engine ran perfectly for 6 months and then one day while cursing down the road at a leisurely 55 mpg, all hell broke loose. By the time I coasted to a stop, that engine was total scrap except for the 4" forged merc crank and 3 lifters. A couple of rod pieces were actually laying in the frame rail.
When I tore it down, you could see from the rod bearing wear that it had been wobbling slightly.
My 2 cents of advice would be to replace that rod. Sure wish I had!