The cracked flathead is a myth. Shhhhhhh...

My good ratio over the past 5 years is 63% out of 27 total; 3 were 59A and the rest 8BA.

Since shop time is money I do my own pressure test before magnaflux and after visual and a molasses dip to thoroughly clean the passages. Made up a plate to block off the water pump area and an adapter that clamps on to the head outlet. Fill it up with water, put on the adapter and bring the pressure up to 30# and let sit for 10 minutes. Drain from the pump area, pull head and look for wet where no wet should be. Then repeat on the other side.

I figure if it is a leaker it isnt worth spending money on a magnaflux. I have one block that I am seriously tempted to use. It has an ever so slight leak at an exhaust port at 30# and is dry as a bone at 16. A tube of Alumaseal might save it. An old circle track motor that is .125 over, P&R and never put together; be a shame to scrap it! It came with a complete SpeedOMotive kit still in the box.

 

Your test sequence makes good sense, Carl. BTW, that old race motor sounds like it's worth a bit of added effort to seal it up so it can finally live as it was intended to.

 

Afraid I'm one for three on flatheads also. Bought a nearly complete '46 motor years ago; Edmunds heads, Weiand intake and H-C cam. Wasn't froze up and I thought I had a good one until it was Magnafluxed. Cracked from the valve seat into the cylinder in three holes. That block went to the dump.

Next was a motor out of a '49 F1 that had belonged to a friend years ago. It had been running well when it was pulled, but...removed the heads and 5 cracks were visible to the naked eye. That block went to the dump.

Finally found a '52 truck motor that was mostly complete. Had to sleeve 2 cylinders because of scoring, but NO cracks. One of these days, I'll get around to finishing it off and getting it in the '40.

That's my story and I'm sticking to it.

 

ANd for those that have cracked blocks, a pal that happens to build his own cranks,blocks etc was in the shop today. He metioned his experience this week with a method to repair cracks........nothing we have seen so far. I will keep you posted.

 

there is a fellow I ran into the other day while hauling garbage away (in the '56...hooray! I got it home!), he drove up in a '51 Ford PU, we talked for a bit, I discovered he has a '50 PU for sale with a flattie in it...and the one powering the truck he was driving is to be for sale soon, as he is doing the unthinkable and putting in a SBC....it didnt seem to smoke or steam or nothin...dont know what I will do with a flattie and runnin gear, but now, I definately know it will be stored UPSIDE DOWN....yes, i'm buyin it, and someday, I will have somethin to put it in...

lol, I have to put my tools in the back of the house, close to the backyard and run my air hose out the window, guess the flattie will be in there too, not havin a shop sucks, but, keepin everything locked safely indoors keeps punk kids and spyin eyes from walkin up and walkin off with them....

the good ones are out there, but harder to find than a '58 pontiac bellhousing, huh rocky???

 

Ran a cracked flathead for two years. It was okay. Pinned.