BiG block, Small Block

What makes the cars engine be defined as having a big block or a small block.
what is the median to seperate the 2.

The declaration of block size is really based on the Block itself. But basically for Chevy 350 and under is a small block, Ford 351 and under is small block. There are some exceptions, I know Ford so maybe some1 else can tell u chevys.

Ford 351 Windsor small block, 351Cleveland and 351m/400 both big blocks

In Mopar a 383 can be a small block or a big block, they made both. If an engine has wide valve covers, it's a big block, if they are narrow it is a small block. Chevy made a 400 small block for a little bit.

As you can tell from the above posts, "small block" and "big block" is just the name give to differentiate the (usually) two different engines made by a manufacturer. The two different engines (big and small) have different exterior dimensions.

There was recently a thread about this (among other things) in the Honda/Acura Technical forum:

http://www.automotiveforums.com/vbulletin/t23140.html

:cool: