The Ford Barn - View Single Post

tubman · 05-13-2018, 11:54 AM

I just sold an uncracked 8BA to a fellow up here building a hot rod. It came out of a 41,000 mile '50 Ford that a tree fell on in a storm in 1954. Someone tried to repair the damage by using a cutting torch to cut through the windshield posts and ended up setting the interior on fire. The car sat in a garage until the late eighties, when I bought it. I parted the car out and saved all of the good parts. A couple of months ago, this guy called me, hearing I had some engines. We made a deal on this one, because I had come to the conclusion that I'll never get around to using it. We pulled the heads, and there were NO "part number" or other cracks. A subsequent magnaflux and pressure test confirmed that this was a completely crack-free block.

My theory is that this was an almost new car when it was damaged and put away, and had never had a chance to overheat or be abused. This leads me to believe that the cracks are caused by abuse (overheating) when the cars become older and less valuable, and that properly maintained flatheads will probably not be cracked. This is confirmed by the fact that the engine that I pulled out of my 82,000 mile '51 Ford shows no "part number" or other cracks either. This engine came out of a "Sunday car" purchased originally by two bachelor farmer brothers to go to church in. After the last brother passed, the car was left to their elderly cleaning lady who couldn't drive. I bought it from her nephew and can assure you that that car was never abused or overheated either.

I pulled the engine from that car because it started making a funny noise I could not track down. I checked a number of things, including the fan bearing and throwout bearing and still couldn't find the noise. Although the engine ran good with excellent oil pressure, I decided to replace it before something bad happened. I replaced it with a '51 Mercury engine I had. Fords and Mercury's used different oil pans, so I removed and cleaned them so I could put the Ford pan on the Merc. In the bottom of the Ford pan I found a chunk of the thrust surface of the rear main bearing lying in the bottom of the pan. I am sure that is what it is because I had a set of new main bearings "in the box" to compare it to. In talking to my machinist we came to the conclusion that it had to be either a defective bearing or more likely an "assembly error".

I think Ford did a better job on these castings than anyone gives them credit for these days.

05-13-2018, 11:54 AM	#48
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 12,143	Re: Why do Flathead V8 Blocks Crack? I just sold an uncracked 8BA to a fellow up here building a hot rod. It came out of a 41,000 mile '50 Ford that a tree fell on in a storm in 1954. Someone tried to repair the damage by using a cutting torch to cut through the windshield posts and ended up setting the interior on fire. The car sat in a garage until the late eighties, when I bought it. I parted the car out and saved all of the good parts. A couple of months ago, this guy called me, hearing I had some engines. We made a deal on this one, because I had come to the conclusion that I'll never get around to using it. We pulled the heads, and there were NO "part number" or other cracks. A subsequent magnaflux and pressure test confirmed that this was a completely crack-free block. My theory is that this was an almost new car when it was damaged and put away, and had never had a chance to overheat or be abused. This leads me to believe that the cracks are caused by abuse (overheating) when the cars become older and less valuable, and that properly maintained flatheads will probably not be cracked. This is confirmed by the fact that the engine that I pulled out of my 82,000 mile '51 Ford shows no "part number" or other cracks either. This engine came out of a "Sunday car" purchased originally by two bachelor farmer brothers to go to church in. After the last brother passed, the car was left to their elderly cleaning lady who couldn't drive. I bought it from her nephew and can assure you that that car was never abused or overheated either. I pulled the engine from that car because it started making a funny noise I could not track down. I checked a number of things, including the fan bearing and throwout bearing and still couldn't find the noise. Although the engine ran good with excellent oil pressure, I decided to replace it before something bad happened. I replaced it with a '51 Mercury engine I had. Fords and Mercury's used different oil pans, so I removed and cleaned them so I could put the Ford pan on the Merc. In the bottom of the Ford pan I found a chunk of the thrust surface of the rear main bearing lying in the bottom of the pan. I am sure that is what it is because I had a set of new main bearings "in the box" to compare it to. In talking to my machinist we came to the conclusion that it had to be either a defective bearing or more likely an "assembly error". I think Ford did a better job on these castings than anyone gives them credit for these days.