[specrocz]

I picked up a 21' day cruiser last fall and ended up having to winterize before I could take it out for a spin. While winterizing, after pulling the exhaust manifolds and removing the drain plugs on the block, I discovered a hard solid material behind both plugs. My best guess is this is Block-fill. What I don't get is why would this be done to a marine 454 Chevy? The prior owner didn't know about it and so far doesn't have the information on the building of this engine. If anyone knows why fill a block and what benefits or liabilities of having a filled block there are, please reply to this post. Thanks..:detective:

 

[Clanton]

block filler

The filler makes the bore more stable mostly in a tall deck for putting out larger amount of hp or to use an old block that has been overbored too much and so on.You not knowing the history of the engine is of concern here.

 

[hullofjustis]

I picked up a 21' day cruiser last fall and ended up having to winterize before I could take it out for a spin. While winterizing, after pulling the exhaust manifolds and removing the drain plugs on the block, I discovered a hard solid material behind both plugs. My best guess is this is Block-fill. What I don't get is why would this be done to a marine 454 Chevy? The prior owner didn't know about it and so far doesn't have the information on the building of this engine. If anyone knows why fill a block and what benefits or liabilities of having a filled block there are, please reply to this post. Thanks..:detective:

could be just sand packed behind the drain plugs. it happens to bbc all the timeif you take pressured air and blow into the drain it should loosen it up.