what is the difference between a big block chevy engine and a small block?

The overall size of the block.

they are totally different motors the big block is larger but the main difference is
the big block Chevy has canted valves like a ford 351 Cleavland.
this helps with air flow and makes it one of the best motors of all time

anything bigger than a 302 is considered a big block and smaller than a 302 is a small block

The small blocks are used for the smaller displacement engines such as 305 cubic inches. Big blocks are used for the larger engines such as 454ci. Basically, you can only bore out a cylinder (to increase displacement) so much until you need a bigger block. As far as performance, drag racers prefer big blocks for the high amount of torque and road racers like the small blocks because they are light and the car stays agile.

Cubic inches,most big blocks are over 350cid

The size of the block.

overall size, sometimes a bigger cylinder bore, longer stroke, heavier wieght, more power, the original big three all had big and small block engine families, and some are confusing, fords had a 351c that is a small block and a 351m/400m that was a big block but still different than the 390, 460 ect
chevy had a small block 400 and a big block 400 which was actually a 402ci, there are also tall deck big blocks in the chevy family which are truck engines for the 2 ton series

A small block chevy is a 350ci or smaller with the exception of there is a small block and big block 400ci you should be able to look at the heads and valve covers and they are a good bit larger than small block

It’s a difference in engine platform (design), not displacement. For example, Chevrolet built a 366 ci big block (commercial) and a 400 ci small block, therefore you can’t judge based on displacement. Small block Chevrolet’s use a block with a 9″ deck height while std. big blocks have 9.8″ deck height. Big blocks also use splayed valve configuration cylinder heads, longer connecting rods, push-rods, etc. In short, they are totally different designs and just about everything is dimensionally bigger or of a different design in a big block. The same basically holds true for Ford, Mopar, etc.

POWER!!!!!!!!!!!!!!!

what is the difference between a pick-up and a tractor semi.everything is…they just do the same job..big block-more power,big bucks,more torque,more weight,