Small Block Versus Big Block (i.e. GM Chevy applications)
When you ask the engine experts about this on-going debate, it will seem that the jury is still out regarding siding with one or the other, in all cases, conditions and applications. IT DEPENDS would be a good response (for now at least). Small block engines have a proud history and remain popular, specifically for their delivery of torque. Large or big block engines have gone through rounds of redesign and upgrades.
What are the basic differences between long block and short block?
The Chevy V8 small block engine is one of the most famous engines throughout history, also called the “mouse”, it sports highly compact dimensions 4.3 – 6.6 L engines. The most popular engine configuration is the 5.7 Chevy small block engine. (no longer offered in GM vehicles, since 2000) It is a little known fact that over 90 million of them were actually built! Descendants of this small block engine are the GM LT engine and GM LS engine.
SB 1, SB 2 and Generation 1+ iterations of the small block engines were manufactured. The LS series V8 small block is all-aluminum with 6-bolt mains, freely used in models like Corvette, Pontiac GTO and Cadillac V-series, as well as the now retired Camaro/Firebird V8 models.
Characterized by rough displacement and bore spacing (4.4 in), eventually reduced down to 3.9 in and the stroke longer at 3.62 in for greater torque, cast iron block, new intake and injection technology and coil-on-plug ignition, square four-bolt design cylinder head with flat pistons. all-aluminum 5.7 liter (5665 cc) pushrod engine and produces between 305 and 350 hp (228 to 261 kW) and 375 ft·lbf (508 N·m) of torque, depending on the application. Beginning in 2001, the LS1 received the higher-flowing intake from the LS6, and a smaller camshaft to keep power at the same level; this also allowed GM to remove the EGR system. The block is very similar to that of the higher-output LS6; beginning in 2002, some LS1 engines were actually built using the LS6 block instead
For a full listing of the different generations and iterations of the long and short block GM engines and their various applications and engine configurations see Wikipedia at http://en.wikipedia.org/wiki/Chevrolet_Small-Block_engine#Generation_III_.2F_IV
For big block applications for the V8 Chevrolet broke the mould and designed a whole new big-block or large block design for large displacement use. Generation 1 engines, manufactured between 1958 – 1965 were used in Chevy cars and trucks. (cast iron, 2-bolt main bearing caps) Versions included the 348, 409/427 with larger valves on the bigger engines. Generation II models included the infamous RAT or mystery MARK IV engine with dual-plane placement of the valves that is the key to performance. Heavier, stronger and with a more durable block.
An excellent source of information about the different models, versions, generations, iterations and modifications made on both the small and large block engines are to be found in the book by Peter C Sessler (1999). Ultimate American V8 Engine Data Book, MotorBooks/MBI Publishing Company. ISBN 0760304890. According to quality sources, Chevrolet had two different V8s, the big-block and small-block. Today, there are only three V8 engines produced by GM: Chevrolet's Generation IV small-block and big-block, and Cadillac's advanced DOHC V8, the Northstar.
Wikipedia also defines a big-block engine as a North American V8 engine, in a family of engines, which generally have greater than 5.9 liters (360 cubic inches) of displacement; factory engine sizes reached a peak of 8.2 liters (500 cubic inches) in Cadillac's 1970s range.
Since then manufacturers have responded to the need for superior engines, as well as the need to replace surviving worn-out, decades-old big-block racing engines, which have been rebuilt too many times. In 2002 General Motors released the carbureted Chevrolet 572 crate engine (9.4L), available for installation in most vehicles, which have enough room under the hood, both in a 620 horsepower street version, which runs on premium gasoline, and a 720 horsepower version, which requires racing fuel. Mopar (Chrysler) recently released the 528 Hemi (8.7L) crate engine. Both of these incorporate modern hardened metals and are able to run on unleaded gasoline. Big-block V8s were most commonly used in full-size and luxury cars, rather than performance vehicles. Thus, they were commonly tuned and built for smoothness, low-end torque to get heavy cars rolling and effortless cruising. Many big-block engines were less technically sophisticated than their small-block counterparts, and their power-to-weight ratios were often lower. Today of course big-block engines are used in racing.
Compare the Ford FE engine and Ford 385 engine , General Motors Chevrolet Big-Block engine and Cadillac V8 engine, as well as ChryslerB, RB and Hemi engines
Source: Retrieved from http://en.wikipedia.org/wiki/Big-block
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