Why do Flathead V8 Blocks Crack?

[TomT/Williamsburg]

Other cracks probably came about from overheating issues. The earlier blocks had plenty of sand left in them once they left the factory, resulting in some overheating. The treatment or inadequate treatment of the overheating issues were probably more cause for cracking than anything else. If you ever talk to H&H flathead they will tell you they have never come across a cracked flathead block they could not fix. I certainly would not pay for their rebuilt engine prices knowing that but I am sure there are many who have and had no issues.

In my limited experience I have dug out a gallon pail or more of sand out of several 59ab blocks. These blicjsca a were relatively crack free and have severed me well since their rebuilds.

I guess, in the end, it's a bit if luck, acquired knowledge about overheating, and how you drive and build them that really determined whether you have a really good block or not that will not overheat. Sorry to have rambled a bit ...