Re: 1957 35HP Big Twin (hitting hard Knocking)
Will that cracked part come out? and buy new one?
The block is in a nutshell the aluminum part that houses the cylinders, pistons, crank, etc... It's the base of the engine if you will.
What you see broken is the part of the block that the cylinder sleeves are pressed into at the factory. The sleeve is that inner circle that the piston lives in, it's made out of steel, and is used because the piston rings would wear away a cylinder very quickly if it were just bare aluminum. Unfortunately it's all integral to the block. You can't replace pieces of the block, because it's all one piece.
You can however get a replacement block and transfer parts if you're so inclined, or an entire powerhead which would be the majority of the engine that bolts to the mid section. Parts, and pieces are still available, some new, some carefully used. If this is beyond you, you have two more options.
Sell it whole as it is to someone who either wants a parts motor for their runner, or wants to do the work to fix her up
OR....
Turn her into an organ donor by either parting her out to others, or using her good parts to fix up another engine in better shape.
What ever you do, don't toss or scrap her. She's worth way more than that....
Now's the time to sit down, and have a beer or two, and carefully consider your options...