Big block / small block - difference?
 

So what's the differnece between these two engine blocks?
Benefits?

Well I dont know all the technical stuff like some do. But basically what I know is that small blocks are RPM motors where as bb's are not. Not saying that they cant push the RPMs, they just dont like to. Also growin up I equated bb's w/gas hogs. Of course my bb 300 doesnt do too badly on gas...........ok yea it does, but thats not the point, LOL

Just displacement. Big block=bigger displacement=more power. You can build a small block to be as powerful as a big block. Alot of guys do this because small block parts are cheaper and a small block is easier to fit in the engine bay. Big blocks are bigger and harder to fit into some vehicles. There is no comparison though between a built small block and a built big block the power and torque are much greater in a big block.

Well you have different overall size of engine so they don't fit the same compartment. Different fuel mileage, different power types...horse power vs torque. Cost factor going in...cost factor to build up. Incompatability for swapping and keeping the same trans, driveline. More weight = heavier front end.

Then there's the WOW factor... a tire ripper at low rpms or a high rpm screamer.

what is the difference between a chevy 350 small block and a pontiac 350 big block? Is it just a thicker block casting? I've never really understood this myself, I just like more cubes :-X10

So it makes sense to have a larger block engine on an F250 and higher then, right?

Heck yeah! depending on what year you go with get the 460 or the V-10. The small block is to small for a F250. But to get the best of both worlds, good gas mileage and gobs of power go with a PSD. There is a guy that has a F-250 PSD SD 4x4 crew cab 8' bed with a 6" lift and 35" tires, he has it propane injected, nitrous injected, dual stack exhaust system, performance upgrades on the turbo and chiped and does the 1/4 mile around 12 seconds! It still gets 20 miles to the gallon too! :-X01 Diesel is the way to go! :-X10

big block is good for towing, whether ford 460, chevy 454 or any diesel.

Small block is good for every day stuff. But you don't want 460 for an every day driver, with 9mpg.

Very true! I hardly drive mine. Maybe once a week if that. Los Angeles gas prices are $2.30 a gallon for regular! I guess the hippy sierra club members are getting there way. :-arrgh

this has been beat to death elsewhere on the site......

There is nothing that makes something a small block or a big block. Its something the manufacturs would have decided.

I have heard that the difference between a big block and small block is the width of the intake manifold.

Alot of the differences are the distance between the cylinders...thickness of the casting. Try to bore out a smallblock..and you don't get very far. Example: 302. Then go to a 460 and try boring that out. WOW big difference.

Big blocks will generally consume more gas, be more expensive, and have a lower rpm where their power comes on.

It's hard to put definative technical specifications on it. I've asked this question myself back in the day. Basically it depends on the casting thickness on the bores. You can bore the hell out of a big block...but a smallblock will quickly reveal that you now have paper thin water jackets.

thats funny because I thought most of all fords bore spacing is 4.38 inches.

Get a Ford Racing parts book from a dealer, they have all of the major engine dimensions in a chart in the back.