What I know about the Diamond block:
The Diamond was the factory identification for post production replacement manufactured engine parts. The blocks had a diamond cast into them just above the cam gear inspection cover. The heads had the diamond cast under the water pump boss. There were A diamond blocks and B diamond blocks. The Diamond block castings are the same as what ever the factory was making when they stoped putting them in production vehicles.
Diamond A engine-
Same as the late '31 block. only difference I've seen is the rear main boss is beefier. Some people have noted hardened valve seat in the exhaust. No verification that this was done by the factory. There are reports of people that have these engines with counter weighted cranks, but if they did come from the factory that way, then they were very late (40's prewar) replacement engines with the pinned on counter weights.
Diamond B engine -
Block is same as last of the production build. Not all had counter weighted cranks. These were avalible as complete engines OR bare blocks. If you needed a new block this is what you got from the dealer as a replacement. Diamond blocks do not always mean that there is a counterweighted crank inside!!!!!!!!! I've been told that the casting is thicker in some areas, but I have not fond anything to document that.
The easiest way to tell if the engine has counter weights is to pull the breather tube and shine a flash light down in through the hole in the block. if you rotate the crank, you can see the #2 crank throw. If you see weights, your Money.
The Diamond was the factory identification for post production replacement manufactured engine parts. The blocks had a diamond cast into them just above the cam gear inspection cover. The heads had the diamond cast under the water pump boss. There were A diamond blocks and B diamond blocks. The Diamond block castings are the same as what ever the factory was making when they stoped putting them in production vehicles.
Diamond A engine-
Same as the late '31 block. only difference I've seen is the rear main boss is beefier. Some people have noted hardened valve seat in the exhaust. No verification that this was done by the factory. There are reports of people that have these engines with counter weighted cranks, but if they did come from the factory that way, then they were very late (40's prewar) replacement engines with the pinned on counter weights.
Diamond B engine -
Block is same as last of the production build. Not all had counter weighted cranks. These were avalible as complete engines OR bare blocks. If you needed a new block this is what you got from the dealer as a replacement. Diamond blocks do not always mean that there is a counterweighted crank inside!!!!!!!!! I've been told that the casting is thicker in some areas, but I have not fond anything to document that.
The easiest way to tell if the engine has counter weights is to pull the breather tube and shine a flash light down in through the hole in the block. if you rotate the crank, you can see the #2 crank throw. If you see weights, your Money.
