Dodge RamCharger Central banner
1 - 12 of 12 Posts

·
Registered
Joined
·
1,456 Posts
Discussion Starter · #1 ·
ok what is the diff between the to?like with chev you can get a BB 350 and a SB 350.is it just the heads? or the displacement?what is the diffrince from a BB and a SB?
 

·
Registered
Joined
·
7,749 Posts
bigger physical size to fit the bigger inches, factory at least. You can build a small block bigger inch than a big block. Dodge also has two different common big blocks, "B" and RB". The RB's have a higher deck height to accomodate a longer stroke.

Common small blocks ("A" or "LA" engines) include the 318, 340, and 360
B series includes the old 361 and 383 and 400
RB includes 413, 426, and 440
 

·
Registered
Joined
·
1,056 Posts
Donk said:
bigger physical size to fit the bigger inches, factory at least. You can build a small block bigger inch than a big block. Dodge also has two different common big blocks, "B" and RB". The RB's have a higher deck height to accomodate a longer stroke.

Common small blocks ("A" or "LA" engines) include the 318, 340, and 360
B series includes the old 361 and 383 and 400
RB includes 413, 426, and 440
That was covering the majority of the Mopar sizes.
Small blocks also had 273 & 340.. distributor in the back.

Big blocks had a 350 ci in the B series. and there was one or two sizes available in both B & RB; but can't remember which ones. Also distributor in the front.

Few parts interchange between big block and small block. Basically.. on Mopars.. they are two completely different animals.
Aaron Wyse
 

·
Premium Member
Joined
·
8,998 Posts
chevy had a big blkock 350 ??? News to me....they did have a small block 400, and a bb 400 (really 402)..but a chevy BB 350 ?????
 

·
Moderator
Joined
·
2,317 Posts
TheRamChargerMan said:
chevy had a big blkock 350 ??? News to me....they did have a small block 400, and a bb 400 (really 402)..but a chevy BB 350 ?????
wonder if he means gm 350, buick,olds,pontiac. ::)
 

·
Premium Member
Joined
·
5,548 Posts
yea the 348/409 is considered a big block with the wedge combustion chambers built into the block. The smallest Chevy big block in the common big block family is 366 ci and is or was used in medium duty trucks.
 

·
Premium Member
Joined
·
7,231 Posts
It's all about displacement flexability. You can find a small displacement big block or a big displacement small block. Chevy was the first to create commonality in their blocks. By using one design, they were able to create several different displacement engines while using basically the same engine block.

In the late 1950s there was a race for greater horsepower by the big three auto manufacturers. In those days the easiest way to make more power was to increase displacement. Many existing engines had smaller displacements. The first big blocks were of smaller displacement, but thru their design, they could eventually be punched out to much greater displacement as each manufacturer tried to stay ahead of the competition.

Mopar followed the concept of two basic engines that Chebby started and had it's own small and big block engines. Furd otoh, created engine families which had some flexability in displacement design, but made a mess in understanding it all, and it made Furds more expensive to modify cheaply as compared to Chebby. Furd had the most overlap in engine displacements. The 352 F.E., 351 Winsor, 351 Cleveland, 351 Modified, and even the Furd 360 (Based on the FE block)were all similar displacements, but were all different engines with little in common.

Ed
 

·
Premium Member
Joined
·
5,548 Posts
I could argue the point of if Chevy had the first engine family with some commonality. The A engine family and Chrysler Hemi precededed the small block Chevy by several years. The Horsepower race wasn't really on till the 60's. There were just a few high end cars in the 50's that had the big horsepower engines such as the Corvette, T-bird and 300.
 

·
Registered
Joined
·
147 Posts
The terms "big block" and "small block" are relative. This describes a situation where one manufacturer makes two or more different V8 engine blocks. For Chrysler, the 273/318/340 and 360 share many parts and similar blocks, and are of one "engine family", hence the LA designation.

The B and RB family of blocks is completely different, and are physically (by outside dimensions) larger than the LA blocks. Therefore, for MOPAR, LA = small block, only because it is smaller than a B or RB, which are considered Big Blocks, only because they are bigger than the LA blocks.

For other manufacturers, such as Pontiac or AMC, there are no "Big" or "Small" blocks, since all Pontiac V8s (except the 301) and all AMC V8s are the same external size. So, an AMC 304 is no smaller on the outside than a 401. So a 304 isn't a small block, and a 401 isn't a big block, because they are both the same size on the outside. Same is true for a Pontiac 326 and 455 and everything in between.

Chevys use a different engine design for their 305/350/400 engines (small blocks) than their 396/402/427/454 engines (big blocks).

So, yes, it can get confusing, especially when you get into the numberous different Ford engines that are all different sizes...for example, the new 4.6L DOHC engine is actually BIGGER than the old 429 engine...by external dimensions...:)

So, this is why you can have Mopar 360 small blocks and Mopar 350 big blocks (first year for wedge big block, they made a 350 cubic inch B engine). There are also 383 RB blocks, 1959 or 60 or both.

Chevys can have 400 small blocks and 396 big blocks.

Displacement has nothing to do with it, it's all about external physical size (height, width, weight, etc.) and relation to other V8s made by the same manufacturer. Make sense? :)

JS
 

·
Registered
Joined
·
1,456 Posts
Discussion Starter · #12 ·
thanks for the help there guys.you can never know to much
 
1 - 12 of 12 Posts
Top