Small Block, Big Block what is the differnece?
Instructor
Joined: Nov 2016
Posts: 154
Likes: 35
From: Santa Cruz CA
This is kind of funny because guys... no one who has experience around engines is going to have any confusion about this. Bore size/spacing was a differentiation between the small block and big block, but the displacement numbers have nothing to do with the physical size of the engine. Big blocks are much physically larger, with as another poster pointed out, much larger valves/covers, larger pistons, all visually obvious physical engine characteristics.Thankfully I don't think we're ever doomed to become the type of community where the difference between horsepower and torque has to be explained constantly... but learning a bit about engine models and their history will prevent embarrassing face to face conversations. We're all car people here, usually there's a right answer
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,442
Likes: 2,187
From: Buffalo Texas
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,442
Likes: 2,187
From: Buffalo Texas
google search,
The small block Chev was called a mouse motor first, which led to the thought line "a bigger mouse would be a rat". The "mouse motor" term stemed from that age old battle of brand loyalty. It began when the Hemi folk started calling their engines "elephant motors" because of their large size. The sbc folk had pride in their engine's ability to make big power from it's comparatively smaller size. Thinking of the old wives tale about elephants being afraid of mice, the rag line resulted in the term "mouse motor".
The small block Chev was called a mouse motor first, which led to the thought line "a bigger mouse would be a rat". The "mouse motor" term stemed from that age old battle of brand loyalty. It began when the Hemi folk started calling their engines "elephant motors" because of their large size. The sbc folk had pride in their engine's ability to make big power from it's comparatively smaller size. Thinking of the old wives tale about elephants being afraid of mice, the rag line resulted in the term "mouse motor".
Burning Brakes
Joined: Mar 2014
Posts: 807
Likes: 239
Rat and Mouse came out of drag racing, not GM. Maybe I confused the issue with the date. Just trying to point out that the small block preceded the big block and was called a mouse before the big block was called a rat. The big block got it's Rat term as a counter part to the mouse not the other way around. The Chrysler hint was there because in the early days of Top Fuel drag racing the two main power plants were the Chrysler Hemi ( nicknamed the Elephant because of its physical size) and the small block chevy. The small block was quite successful against the hemi. Not because of HP but because the elephant over powered the tire technology at the time. The small block's lower power to weight gave them an advantage via traction. As everyone knows elephants are afraid of mice so the hemi killer small block chevy received it's "Mouse" label. Once the big block showed up it became the "Rat" to the Elephant's Mouse.
Burning Brakes
Joined: Jul 2013
Posts: 935
Likes: 103
Big block and small block hey... it's usually something I hear geezers talking about... or mullets with Levi's and high tops. 
LS is all the rage.
i laugh when people call the 7.0L in the C6 Z06 a big block. It's not.
Old school terminology really.
LS is all the rage.
i laugh when people call the 7.0L in the C6 Z06 a big block. It's not.
Old school terminology really.
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,442
Likes: 2,187
From: Buffalo Texas
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,442
Likes: 2,187
From: Buffalo Texas
Rat and Mouse came out of drag racing, not GM. Maybe I confused the issue with the date. Just trying to point out that the small block preceded the big block and was called a mouse before the big block was called a rat. The big block got it's Rat term as a counter part to the mouse not the other way around. The Chrysler hint was there because in the early days of Top Fuel drag racing the two main power plants were the Chrysler Hemi ( nicknamed the Elephant because of its physical size) and the small block chevy. The small block was quite successful against the hemi. Not because of HP but because the elephant over powered the tire technology at the time. The small block's lower power to weight gave them an advantage via traction. As everyone knows elephants are afraid of mice so the hemi killer small block chevy received it's "Mouse" label. Once the big block showed up it became the "Rat" to the Elephant's Mouse.
Instructor
Joined: Nov 2016
Posts: 154
Likes: 35
From: Santa Cruz CA
My job involves working on cars, and I'm near Monterey in California, so there's a huge number of classic cars and restoration shops around and this stuff comes up all the time.I'm 33, but I kind of already feel like a fossil when it comes to cars. Manuals are dying out, gas engines are dying out, and performance cars are nowhere near as popular with kids as they were when I was a teenager. I think to a degree, this'll happen to all of us
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Burning Brakes
Joined: Mar 2014
Posts: 807
Likes: 239
Don't know where that reply came from. Nobody was trying to show you up. Just throwing out some old history not everyone may know. When I'm wrong I own up to it, apologize and move on without any sarcasm. I thought more of you than that. Disappointing.
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,442
Likes: 2,187
From: Buffalo Texas
Racer
Joined: Nov 2013
Posts: 277
Likes: 37
From: Central Mississippi
Norcalace I love the avatar. Not many around that knows what a Vega is, much less dreaming of a V8 (mouse or rat 
) conversion. My first car was a Vega and I read more HOTROD mags than I can remember about V8 kits. If Im not mistaken, Hooker and Doug Thorley both had header, motor mount and radiator kits. Would love to see more photos.
) conversion. My first car was a Vega and I read more HOTROD mags than I can remember about V8 kits. If Im not mistaken, Hooker and Doug Thorley both had header, motor mount and radiator kits. Would love to see more photos.
Last edited by DRAFT1; Jan 8, 2017 at 04:34 PM.
Burning Brakes
Joined: Mar 2014
Posts: 807
Likes: 239
Norcalace I love the avatar. Not many around that knows what a Vega is, much less dreaming of a V8 (mouse or rat ) conversion. My first car was a Vega and I read more HOTROD mags than I can remember about V8 kits. If Im not mistaken, Hooker and Doug Thorley both had header, motor mount and radiator kits. Would love to see more photos.
) conversion. My first car was a Vega and I read more HOTROD mags than I can remember about V8 kits. If Im not mistaken, Hooker and Doug Thorley both had header, motor mount and radiator kits. Would love to see more photos.Last edited by norcalace; Jan 9, 2017 at 08:37 AM.
Melting Slicks
Joined: Oct 2005
Posts: 2,989
Likes: 352
From: Carson City Nevada
I must really be old school because when did all this liter crap start!? It seems like it went from cubic inches to liters overnight. I always know when I'm talking to a real hot rod guy, because "liter" never enters the conversation.
Last edited by o2bnkc; Jan 9, 2017 at 03:44 AM.
Melting Slicks
Joined: Oct 2005
Posts: 2,989
Likes: 352
From: Carson City Nevada
Norcalace I love the avatar. Not many around that knows what a Vega is, much less dreaming of a V8 (mouse or rat ) conversion. My first car was a Vega and I read more HOTROD mags than I can remember about V8 kits. If Im not mistaken, Hooker and Doug Thorley both had header, motor mount and radiator kits. Would love to see more photos.
) conversion. My first car was a Vega and I read more HOTROD mags than I can remember about V8 kits. If Im not mistaken, Hooker and Doug Thorley both had header, motor mount and radiator kits. Would love to see more photos.
Le Mans Master
Joined: Mar 2004
Posts: 8,700
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From: Ft. Lauderdale Fl
Burning Brakes
Joined: Mar 2014
Posts: 807
Likes: 239
Melting Slicks
Joined: Apr 2008
Posts: 2,703
Likes: 167
From: Western Washington
They make 454 small blocks
that is a LS engine !!
The LS based GM small-block engine is the primary V-8 used in General Motors' line of rear-wheel-drive cars and trucks. Introduced in January 1995, it is a "clean sheet" design with only rod bearings and bore spacing in common with the longstanding Chevrolet small block V8 that preceded it as the basis for GM small-block V8s. The LS' basic layout owes a good deal to Ed Cole's original small-block design of 1954-55,[citation needed] though it also uses cues from Buick, Oldsmobile, and Pontiac V8s. The basic LS variations use cast iron blocks, while performance editions are all aluminum with cast iron cylinder liners.
The LS small-block has been manufactured in three Generations – III, IV, and V – with preceding Generations I and II of modular GM small-block engines having been based on the Chevrolet small-block V8 originally designed in 1955. GM recycled the "LT" designation previously used on Chevrolet small-block V8-derived "GM" engines beginning with the LS Generation V "LT1" in 2014.
Several versions of the LS were used in the Chevrolet Corvette, beginning with the LS1 in 1997 through the LS9 and others in 2013. Variants of the LT version of the GM small-block have been used since.
The LS based GM small-block engine is the primary V-8 used in General Motors' line of rear-wheel-drive cars and trucks. Introduced in January 1995, it is a "clean sheet" design with only rod bearings and bore spacing in common with the longstanding Chevrolet small block V8 that preceded it as the basis for GM small-block V8s. The LS' basic layout owes a good deal to Ed Cole's original small-block design of 1954-55,[citation needed] though it also uses cues from Buick, Oldsmobile, and Pontiac V8s. The basic LS variations use cast iron blocks, while performance editions are all aluminum with cast iron cylinder liners.
The LS small-block has been manufactured in three Generations – III, IV, and V – with preceding Generations I and II of modular GM small-block engines having been based on the Chevrolet small-block V8 originally designed in 1955. GM recycled the "LT" designation previously used on Chevrolet small-block V8-derived "GM" engines beginning with the LS Generation V "LT1" in 2014.
Several versions of the LS were used in the Chevrolet Corvette, beginning with the LS1 in 1997 through the LS9 and others in 2013. Variants of the LT version of the GM small-block have been used since.
I was pointing out it was the block size and not just bore and stroke. They do make first generation small block 454 crate engines (not just LS engines).