What changes between a small block and a big block

[Hi-Po]

You forgot the LS7 - 7.0 liters. Isn't the LS3 6.3 liters?

LS7 is still a small block.

[Firebirdjones]

LS7 is still a small block.

Ya if you are talking about LSx motors,,all of which are built from the same platform,,,,,not to be confused with the LS7 454 BBC that was offered over the counter in the early 70's,,,the big brother to the LS6 454 of 70-71.

The LS3 was the option code used for the 402 ci BBC around those years as well.
Isn't it funny how GM just kinda decided to use these terms all over again???

[mbrownin]

LS7 is still a small block.

Yeah, I know that. Just pointing out that there are LSx motors larger than the 4.8 - 6.0 liter range mentioned in the post that I replied to.

[Hi-Po]

Ya if you are talking about LSx motors,,all of which are built from the same platform,,,,,not to be confused with the LS7 454 BBC that was offered over the counter in the early 70's,,,the big brother to the LS6 454 of 70-71.

The LS3 was the option code used for the 402 ci BBC around those years as well.
Isn't it funny how GM just kinda decided to use these terms all over again???

You have great information You have more years of wisdom on me buddy!

Yeah, I know that. Just pointing out that there are LSx motors larger than the 4.8 - 6.0 liter range mentioned in the post that I replied to.

I know, I thought the exact same thing you did. Just never posted it.

[Firebirdjones]

You have great information You have more years of wisdom on me buddy!

I'm stock full of useless knowledge like that

[azfrc]

BTW, the 409 is not a big block. It's kind of by itself.

[redbird555]

Yes theyre from the 348 w motor family. Ive always liked em they dont make a whole punch of power without some serious work but they are rare and dont have a real combustion chamber in the head, not to mention the shape of the head is real cool.

[Z28_Driver]

a simple reason the bbc is still used is that if you can stuff it into a car it will burn rubber and sound good with no modification. its just a very cheap way to make a monster from old used parts.
as mentioned above there are fitment issues, however most rear wheel drive gm cars until the late 1980's will accomodate them with some chassis mods.

[allbaugh_04]

Why is the LS7 7.0 considered a small block, it has big cubic inches and has the same exhaust ports spacing correct?

Can you guys be more specific on the differences of big blocks and small blocks?

BTW big blocks can sound so damn good i heard hundreds of them running around this weekend. My friend has a 1991, i believe, or 1990, can't remember, 454 SS...although it's got a 572 in it...should I post pics?

[shady milkman]

Why is the LS7 7.0 considered a small block, it has big cubic inches and has the same exhaust ports spacing correct?

Can you guys be more specific on the differences of big blocks and small blocks?

BTW big blocks can sound so damn good i heard hundreds of them running around this weekend. My friend has a 1991, i believe, or 1990, can't remember, 454 SS...although it's got a 572 in it...should I post pics?

the CI isnt what differentiates a small to a large block..its the physical size of the block itself among other things ..EVERY lsX block is a small block since their sizes are the same..that is why there are ta's and maros running ls7s and lsx that are 427+ ..all GenIII+ have the big block exhaust port layout ..but are still small blocks

[allbaugh_04]

idk, i guess an LS7 looks pretty big to me, smaller than the 572 i just saw, but it's pretty damn big

[shady milkman]

idk, i guess an LS7 looks pretty big to me, smaller than the 572 i just saw, but it's pretty damn big

the block itself is the same size as your ls1....

[shady milkman]

what might throw you off is how the water pump is tilted to a weird angle and all the accessories' location

[Wesman]

Why is the LS7 7.0 considered a small block, it has big cubic inches and has the same exhaust ports spacing correct?

I don't think you understand. It has absolutely nothing to do with the displacement, or the heads, or the exhaust port spacing. The LS series isn't even tecnically a "small block" anway, its a GEN III V8, but its been called a "small block" by many people since it replaced the original GM small block GEN I/II design.

Its all about the physical dimensions and design of the block itself. The terms "small" and "big" block were merely terms coined to differentiate between two series of V8 engines made by one manufacturer.

The 7.0L LS7 is the same physical size as an LS1 or LS6 or any other Gen III V8.

Can you guys be more specific on the differences of big blocks and small blocks?

Small Block:



Big Block:



LS Gen III Series:

[Firebirdjones]

Those pictures might have helped him more if there were actually cylinder heads on those blocks.
You and I can see the differences, but to a person new to these things??? Know what I mean??

[Wesman]

Those pictures might have helped him more if there were actually cylinder heads on those blocks.
You and I can see the differences, but to a person new to these things??? Know what I mean??

True, I'll see if I can get some different pics.

EDIT: Fixed

[Firebirdjones]

True, I'll see if I can get some different pics

That's cool,,,I'd post pics of my own junk, but the paste linky is gone at the bottom.

[Hi-Po]

That's cool,,,I'd post pics of my own junk, but the paste linky is gone at the bottom.

WHOA! Jones, we dont wanna see that!

[Firebirdjones]

WHOA! Jones, we dont wanna see that!

I deserved that one.

[Hi-Po]

I deserved that one.

Just messing with you!