It's new, powerful, and packed with the latest technology. In 1955 those words described the first small-block Chevy, the 265, with its passenger car rating of 162hp. Soon after the first 265s hit the showrooms, customers sought even more performance and Chevrolet responded with the 283 in '57 and then the 327 in '62. By the late '60s, high-winding 302 engines and powerful 350s continued the trend. By '70, Chevrolet released the big-inch 400 small-block. Later, custom bore and stroke 365 small-blocks, 377, 383, and 406 displacements appeared on the hot-rodding scene.

Today, Vortec and LS-series engines are excellent performers and provide very acceptable fuel economy. The most powerful factory small-block Chevy so far (the '06 427ci LS7 engine) boasts titanium rods, a dry-sump oiling system, an all-aluminum block and heads, and 505 horses. This LS7 small-block will shove an '06 Z06 Vette from 0 to 60 mph in 3.5 seconds, cover the quarter-mile in 11.50 seconds, and continue on to 195 mph; and it's EPA rated at 26 mpg on the highway. Who said good gas mileage cars are boring?

What this all means is that the small-block Chevy has both a tremendous history and a spectacular future. GM has estimated that through 2005, more than 90 million small-block Chevys have been produced. Here we'll chronicle the benchmarks, how hot-rodding has improved power over the years, and where GM development is currently headed. Better cylinder heads, carburetion, fuel injection, improved bore and stroke relationships, and more have all been directed at the engine that is arguably the most hot-rodded in the world. As always, the small-block Chevy is powerful and packed with technology.

Efficient Design With the Gen I
In the early '50s, Chevrolet engineers specifically designed the small-block engine in a compact size to allow a streamlined production process. New innovations, such as greensand casting, meant the block could be cast upside down, thus reducing the amount of cores. The small size of the block provided an economical use of iron and required less cooling effort in service. To provide high-rpm operation, engineers designed lightweight rocker arms from stamped steel. The 265 engines used a 3.00-inch stroke and a 3.75-inch bore. The new small-block's cylinder heads with a cross-flow port structure and wedge combustion chambers allowed for a broad powerband. The new small-block engine was designed with 4.4-inch bore centers (measured as the center of one cylinder to the next) and is the same dimension carried through to the Gen III small-block designed in '97. Other new designs for the small-block Chevrolet included:

* Hollow pushrods to carry oil to the cylinder heads
* A one-piece intake manifold combining the water outlet, exhaust heat riser, distributor mounting, and lifter valley cover in a single component
* An internal oiling system

1 HP/CI Early On
Although at the upper end of engine options, dual quads had been offered on the 265 with a high-lift cam and 240 hp, the era demanded not only more power, but also broadband performance. So the new-for-'57 283 with its 0.125-inch larger bore (3.875-inch bore, 3.00-inch stroke) was available with the standard two-barrel, four-barrel, dual quads, or a new mechanical fuel-injection system that produced 283 hp from 283 ci (1 hp per cubic inch). All cylinder heads for the 265s and 283s used 1.72/ 1.50-inch valves.

For '62 Chevrolet's new hot motor, the 327 (the first small-block with a four-inch bore) packed a wallop. Besides the carbureted versions, a fuel-injected 327 with 360 hp was optional in the '62 Corvette. The cylinder heads used on this engine (and some others of the era) were the 3782461X head with 1.94/1.50-inch valves. These heads had the commonly found double-hump shape on the end of the head. It should be noted that beginning in '64 and through '68, cylinder heads with the double-hump shape also used 2.02-inch intake valves (aka fuelie heads). Castings with 2.02-inch intake valves were also used on the 365hp (Holley carburetion) and 375hp (Rochester fuel-injection) Corvette 327 engines. Except for some early truck applications, it would not be until '69 that all small-block cylinder heads would feature accessory mounting holes.The '67 model year had a lot of small-block excitement. First, the new 350 engines available in the Camaro debuted, and the special high-performance 302 Z/28 package Camaro was released. The 350ci engine with its 3.48-inch stroke and 4.00-inch bore provided good low-speed torque and power. The Camaro-only 350 engine (for '67) produced 295 hp from a two-bolt main block. Other passenger cars would have 350s beginning in '69.

The 302 Z28 engine is the smallest V-8 ever installed in a Camaro to date. It is also the only engine available new in any '67-69 Z28. Based on a 4.00-inch bore and a 3.00-inch stroke, the little engine made lots of power above 5,000 rpm and very little below. This engine's 290hp rating was very underrated. In stock trim, actual power was in the mid-300hp range. These engines were designed specifically to compete in SCCA road racing and came with a huge resume of hardcore race parts: a Holley 800-cfm carburetor, big-runner aluminum intake manifold, 2.02 heads, a high-lift mechanical camshaft (0.485-inch lift), 11:1 compression, full-floating wrist pins, a forged crankshaft, and more. Because the engine did not produce much torque and had such high rpm capability beyond 7,000 rpm, 302 Z28s were only offered with four-speed transmission and were not available with air conditioning. Chevrolet also sold several cross-ram-intake setups (two staggered four-barrel Holley carburetors) and special race camshafts for the early Z28s that helped the 302 gain even more high-rpm power. With some modifications these engines would easily produce power well above 400 horses (at very high rpm).

Cylinder-head flow rates of the era were marginal at best. A typical street/strip small-block with 2.02 cylinder heads would need extensive and expensive port work to produce impressive power from the small (by today's standards) ports. Furthermore, typical cylinder head modifications did not produce good low-speed torque, so performance cars would generally need very low rearend ratios to run in the 12s. Often a 3,500-pound car with a healthy small-block would need at least a 4.56 rearend ratio or lower to run quicker than 13s. This was often the reason many hot-rodders of the era would run big-block Chevrolet V-8s. Here, the higher torque levels (from longer strokes and lots of cubic inches) would mean a 3,500-pound car could run 12s with just 3.73 gears.

Power & Adaptability
For '68 Chevrolet released a larger low-performance 307 engine as a replacement for the 283. The 307 used a 283 bore and a 327 stroke (3.875-inch bore and a 3.25-inch stroke). Production of the 307 ran until '73. By the mid-'70s, the automotive market began to change dramatically and GM sought to raise fuel economy and reduce emissions. One particular displace-ment introduced was the 305 engine (released in '76), which used a 265 bore and a 350 stroke (3.75-inch bore, 3.48-inch stroke). Other new displacements included the 262 (released in '75) and the 267 (released in the later '70s).

By the '80s, the electronic carburetor, on-board computers, and, later, electronic fuel injection helped the small-block achieve improved drivability, lower emissions, and better fuel economy. Through most of this time, the 305 small-block was used on a widespread basis in almost all Chevrolet V-8 cars. The general exceptions were some Camaros, all Corvettes, and most B-body police-package cars, which all used a variation of the 350 engine. Into the mid-'80s, small-block Chevys with factory fuel injection came with roller-lifter camshafts, one-piece rear main seals, and redesigned valve covers secured at four top center points (instead of four around the sides). In the Camaro and Corvette, tuned-port electronic fuel injection helped to significantly raise power and torque levels. By the late '80s, lower-performance Camaros and B-body Caprices received throttle-body fuel-injection systems to replace the electronic Quadrajet carburetors.

The Gen II
By the early '90s, Chevrolet introduced the Gen II small-block in high-performance cars beginning with the Corvette. First known as the LT1 and later the LT4, the Gen II featured new, low-friction internal components and reverse-flow cooling to facilitate the most powerful small-blocks since the musclecar era. When this engine first appeared in the '92 Corvette as an LT1, it developed 300 hp. This engine featured revised cylinder heads, reverse-flow cooling, and OptiSpark ignition.

The engine later became available in '93-97 Z28s and '94-96 Impala SS and police-package Caprices. In the '93 Camaro, the engine developed 275 hp (which improved in a few short years) with tuned-port fuel injection, while in the Caprice, the LT1 produced 260 hp. There are four basic differences between the Camaro LT1 and the Impala SS/Caprice LT1. First, the Camaro uses aluminum heads, as opposed to the steel on the Impala SS/Caprice. Second, the Camaro's compression ratio is 10.5:1, compared to the Impala SS/ Caprice's 10:1. Third, since the Impala SS/Caprice weighs about 650 pounds more, the computer programming is different. And finally, the Camaro's stock exhaust system backpressure is 10 inches of mercury, whereas the Impala SS/Caprice's is 13 inches. Some Gen II features, including the low profile and high-flow intake manifold, used technology that would be designed in the all-new Gen III.

Gen III
The Gen III small-block was introduced as the LS1 5.7L (346ci) engine in the '97 Corvette, while Vortec versions of the Gen III for trucks were introduced in '99. This engine is configured in four displacements, 293 (4.8L), 325 (5.3L), 346 (5.7L), and 364 (6.0L). All 5.7L LS1 engines are aluminum blocks, while most other Gen III displace-ments (typically used in trucks) are cast iron. The best known is the 346, or 5.7L, and may be why many hot-rodders call all Gen III engines LS1.

The Gen III engine benefited from completely new technology (designed from a clean sheet of paper) and production methods, but even still its design drew upon more than 40 years of research and continuous improvements from the Gen I and Gen II small-blocks. Ongoing improvements on the Gen III project also supported the development of new efficiencies and power increases in the Gen IV. In many of today's modified musclecars, the Gen III/LS1 is a very popular engine swap. At the foundation is a deep-skirt, six-bolt main block that definitely has the structure to provide for a strong and dependable engine. What's especially exciting inside a Gen III are the good-flowing cylinder heads with replicated ports. Inside you'll find 2.00-inch intake and 1.55-inch exhaust valves. And if you would like to retain a carburetor, there are LS-series four-barrel carburetor manifold kits available at reasonable prices. Other good news is that used engines of this variety are beginning to surface. To help with an LS1 engine installation, lots of aftermarket companies, such as Year One, offer installation kits for musclecars, like early Camaros. GM also sells an installation book (PN 88959384) for an LS1 or LS6 going into an older vehicle.

The New Gen IV
Recently, GM introduced the Gen IV small-block V-8, 50 years after the first small-block appeared. This engine is available in V-8-equipped models of the '05 Chevrolet TrailBlazer EXT, GMC Envoy XL, GMC Envoy XUV, and in the soon-to-be-released '06 Chevrolet Monte Carlo and Impala. The new LS2 and LS7 Z06 engines are part of this engine family.

Some of these engines now offer fuel-saving Displacement on Demand (DOD) technology, and there are plans to have this feature on all Gen IV engines. This fuel-economizing feature has the capability of disabling the combustion process of half the engine's cylinders during certain driving conditions, enabling fuel savings of up to 8 percent. The process is instantaneous and virtually imperceptible, and the engine delivers horsepower and torque bands comparable to previous non-DOD small-block engines. We've driven new GM vehicles with this feature and the cylinder transition is seamless. Most recently a 6.0L V-8 version of the Gen IV engine without DOD is available in the Corvette.

Looking Ahead
Beyond the latest power numbers, the significance of the small-block Chevy has been how well GM Powertrain has continued to develop a product to surpass market demands by finding new ways to incorporate the latest technology. Just as in the past, the engine is continually positioned to reign the most hot-rodded engine ever. Something we all look forward to.

The Small-Block's Timeline
'55: The small-block V-8 is introduced in '55 Chevrolets as a 265. This is the beginning of the Gen I.

'57: 1/8-inch bore increase raises displacement to 283ci; the Ramjet mechanical fuel-injection system was introduced, bringing horsepower to 283--1 hp/ci.

'62: Displacement increases to 327ci with a 4-inch bore and a 3.25-inch stroke. Ramjet fuel-injected versions are rated at 360hp.

'64: Cylinder head improvements (2.02-inch intake valves) bump the 327's highest horsepower rating to 375 with fuel injection.'67: A little-known option called Z28 is released for the Camaro only, which includes a high-revving 302ci small-block for competition in SCCA Trans Am road racing. A 350ci (5.7L) version (in the Camaro) debuts and will become the quintessential small-block variant.

'68: A Camaro Z28 wins the Trans Am championship.

'70: 350ci LT1 debuts in the Z28 Camaro and Corvette and is rated at 360/370hp respectively; 400ci small-block is offered--the largest-displacement small-block built to date.

'75: With fuel economy prevalent in consumers' minds, a more efficient 262ci small-block is introduced. This engine, offered in the small Chevrolet Monza, makes spark plug replacement next to impossible.

'78: V-6 engine based on small-block design introduced; it would become the Vortec V-6 truck engine more than a decade later.

'80: Last year for the 400 small-block, by now offered only in light-duty trucks.

'82: Fuel injection reintroduced with the Cross-Fire Injection system on Corvette and the redesigned (third-gen) Camaro Z28.

'85: Tuned-port fuel injection replaces Cross-Fire Injection, bringing in the modern era of electronically controlled, port-injected engines.

'86: Aluminum cylinder heads debut as standard equipment on Corvette; block changed to accept new single-piece rear main seal.

'87: Hydraulic roller lifters introduced on fuel injected engines.

'89: The H.O. 350 crate engine offers a ready-built performance engine from the factory, changing the way hot-rodders approach engine-building in the next decade.

'92: The LT1 engine in the Corvette introduces Gen II small-block design, which features reverse-flow cooling, revised cylinder head design, and crank-triggered optical distributor. The engine will later be used in Camaros and will become a favorite of police officers in '94-96 Caprices with a top speed of 140 mph.

'96: The Vortec V-8 engines are introduced in trucks, featuring cylinder heads with swirl-inducing combustion chamber design to increase power and torque.

'97: Gen III 5.7L LS1 small-block introduced with all-new Corvette, featuring all-new deep-skirt block casting with six-bolt mains, redesigned cylinder heads with symmetrical ports and combustion chambers, and coil-near-plug ignition system.

'99: Gen III-based Vortec V-8 engines introduced in GM trucks; displacements include 4.8L, 5.3L, and 6.0L.

'00: The Z06 debuts with the LS6 engine pumping out 385 hp.

'05: The Gen IV small-block is introduced 50 years after the original. LS2 and LS7 are part of this engine series.

'06: 7.0L LS7--introduced in Corvette ZO6--becomes the largest, most powerful small-block ever built.

--GM Powertrain

By now, everyone knows of the havoc caused by Hurricane Katrina. Never before in our country's history has such an enormous number of Americans suffered so greatly from a single-or even series of-natural disasters. There's nothing we can say about the devastation and tragedy that hasn't been said a million times already. To help the victims as best we can, Year One has started the Hot Rodders' Relief Fund to collect donations for the Red Cross relief efforts. Every penny collected will go to the Red Cross.

Year One is in a unique position to quickly and effectively act as a collection center for donations. We have the business mechanisms in place to accept funds from customers via credit card, check, cash and electronically through our phone operators and our website. We have generated a specific part number in our system to track and account for every penny donated to the relief effort, and our system generates and mails a receipt to you for your donation.

All funds collected by Year One and our partners will be given to the Red Cross-there will be nothing "held back" for any sort of administration fees or anything else. Everything collected for the Red Cross will go to the Red Cross, to be used as they see fit. If you would like to help us in our effort, please visit www.yearone.com and click the Hot Rodders Hurrican Relief Fund logo or contact Marci Stevens at (706) 658-2140, Ext. 112, and we can determine the steps required to work with your organization.

COVER SECTION

BUILD ’EM FAST, BUILD ’EM QUICK, BUILD ’EM CHEAP
An introduction to the wild world of ’82-’92 Camaros

TPI REVIVAL
How to run 12s with a normally aspirated TPI Camaro

HANDLE IT!
A third-generation Camaro suspension and handling guide

CHANGING TIMES
A guide to high-performance parts for ’82-’92 Camaros

MY GENERATION CAMARO, PART IV
Better heads and a bigger cam for our 305-powered budget buildup

TECH

FUTURE SHOCK
How to install a TPI system on an ’80s A/G-body Chevy

IT’S A SPRING THING
How to swap valvesprings

HOT, HOT, HOT!
Build a $2,400 small-block that makes over 400 hp

STAYING CONNECTED
Do-it-yourself TH700-R4 lockup converter tricks

ARM YOUR CAMARO
Detroit Speed & Engineering’s new early-Camaro tubular upper control arm

LOG ON—GO FAST
Investigating an inexpensive data logger from Edelbrock

LIVING LARGE
The differences between Mark IV, Gen V, and Gen VI big-blocks

BALANCING ACT
How to pull and install a harmonic balancer the right way

HEAVY METAL
Year One’s slick rear-axle dolly

FEATURES

ALWAYS CLASSIC
Dan Albert’s droptop ’70 Chevelle

SHOW AND GO YENKO
A rare look at a ’70 Yenko Nova

CHARISMATIC VETTE
Bryan Fijolek’s slammed ’64 Corvette

SWEDISH INDEPENDENCE
Bengt Lennartsson’s LT1-powered and Vette-suspended ’55

BEHIND THE WHEEL
Challenging the Bragg-Smith Advanced Driving School

DEPARTMENTS

FAST TALK
Something New

LETTERS
The readers always write

CHEVY PARTS
The latest in trick parts

BOW TIE NEWS
All the Chevy news that’s fit to print

CHEVY SHOWPLACE
Readers’ rides and other cool machines

PERFORMANCE PQA
Your tech questions answered

COVER SECTION: 7 Hot Engine Combos

7 Spicy Power Combos: Horsepower and torque recipes that you can build

TECH

RAT-IFY YOUR CHEVY: Swap tips for converting to a big-block

ALTITUDE ADJUSTMENT: Density altitude and how to use it to your advantage

HEAT SEAL: The latest on the new wave of header and collector gaskets

HOT PIPES: Dedicated early Camaro exhaust systems

SOUND ADVICE: How to install headers on a 350ci Nova

MY GENERATION CAMARO, PART III: Headers, a larger cat, and gears are worth 0.9 second!

SPARK TALK: Matching hi-perf coils and modules for a killer HEI

CAMARO FACE-OFF, PART II: Reassembling an early Camaro front clip

FEATURES

SURVIVAL: A pair of ’69 Camaros that are so original it hurts

MODERN WAYS: Bob Wise’s slick ’56 LT1-powered classic cruiser

SMOKEY—A REAL CHEVROLET HERO: The life and times of Smokey Yunick

CHEVELLE ACES: Everything’s coming up ACES at the Chevelle show

FAST ISN’T ALWAYS PRETTY: Sean Johnson’s subtle-yet-fast street Chevelle

QUICKLY GREEN: Wally Null’s notable 10-second Chevelle

OUT OF THE BOX: A V-8 Corvair road rocket

COVER SECTION: Build Your First Engine

HOMEGROWN HORSEPOWER: An introduction to building your first engine on a budget

DEAL ME IN: Budget small-block engine kits that anybody can afford

BUILD YOUR FIRST ENGINE: The details on how to build it yourself

LOBE PROSPECTING: Dyno-testing Air Flow Research’s new small-block aluminum head

TECH

THE OTHER GUYS: Intake manifolds from alternative sources

AMP IT UP: Testing a Powermaster alternator with shocking results

CRACKED!–How to uncover those elusive cylinder block and head cracks

CHP EDITORIAL SURVEY: Fill out the form and you could win a carburetor!

AGENT 87 LIVES!–We run 13.13 at 103 mph on 87-octane gas and live to tell about it

UPGRADING THE DEUCE: Installing a Meyer Racing IFS in a ’67 Chevy II

SHIFTING BUSINESS: All the details on converting an automatic to a manual trans

BREAKING NEWS: How to install a windshield the right way

IN THE CLUTCH: An inexpensive fix to LS1 clutch problems

FUELISH PLEASURES: Fuel delivery system basics

FEATURES

THE NEED FOR SPEED: Test driving the new ’01 ZO6 Corvette

LIKE FATHER LIKE SON: Dana and Darren McCardle’s monster 572ci Rat-motored Camaro

DRIVING FORCE: Al Noe’s cool ’67 Pro Touring Camaro

CRUISIN’ USA: Ten Hot cruisin’ spots from around the country

BACK TO THE BEACH: John Lewis’ bright red 327 ’57 Chevy

FAST AS YOU CAN!–A look at the East Coast Timing Association’s top speed events

COVER SECTION

Cam Tech Special

THE BUMP & GRIND: An introduction to the wild world of camshafts

CAM BASICS: The whole truth about lift, duration, and all the rest

CAM SELECT: Cam and engine power combinations that are horsepower heroes

LOBE PROSPECTING: Performance Trends’ budget camshaft software

THE TUNE ’N’ TWEAK: How to tune your engine for maximum performance

TECH

LT1/LT4 BUYER’S GUIDE: A host of power-producing goodies for late-model small-blocks

METAL-MORPHOSIS: Goodmark’s new SS 396 ’66 Chevelle hood

NEW-GEN LS6: Lingenfelter builds a 570hp 427ci LS6 street engine

FLOW TO GO, PART 5: CHP tests five more small-block cylinder heads

SILENCE IS GOLDEN: How to install weatherstripping and seals to keep your Chevy quiet

CHARGE IT UP! The lowdown on high-performance alternators

ACCESSORIZE! PART IV: Serpentine accessory drive brackets and pulleys

GETTING IT HANDLED: Improving the suspension on a second-generation Nova

WEB RUNNING: Cool Chevy Web sites

MOUNT UP! A slick electric fan mount

FEATURES

A CHANGE OF HEART: Scott Whidby’s red, Rat-powered ’69 Camaro ragtop

DUAL-QUAD POWER: Dave Corrente’s 409-powered ’62 bubbletop

WAGON II GO: A 406ci-urged Nova with plenty of doors

SOMEWHERE IN TIME: Jeff Paulin’s restoration adventure with a ’66 SS 396 Chevelle

SPECTACULAR PULL-OUT POSTER!

COVER SECTION–Basic Horsepower Tricks

BASIC HORSEPOWER TECH: Entry-level performance how-tos anyone can do

CARB CAPERS: How to rebuild a Holley carburetor

TIMING IS EVERYTHING: The basics on setting ignition timing

THE ALUMINUM TWO-STEP: How to swap an intake manifold with no extra parts left over

IDLE EFFORTS: Setting idle mixture the right way

TECH

GET CONNECTED: Wiring harness tips and tricks

COMMAND PERFORMANCE: Bolting the Ram Jet 350 into an early Nova

MY GENERATION, PART II: Induction and exhaust changes blast the Camaro into the 16s

DON’T GET RIPPED OFF: Tips on your next musclecar purchase

CAMARO FACE-OFF, PART 1: Camaro facial surgery

IN SEARCH OF SPARK: The difference between inductive and CD ignitions

LEADING THE LEGACY: Building and testing a 12-second ’01 302ci Camaro

FEATURES

BOTTLE ROCKET: Milt Decker’s 6-second Pro Outlaw ’63 Sting Ray

RUNNIN’ WITH THE BIG BOYS: Test driving the new NASCAR 4 stock car racing game

AMERICAN IRON: Joe Maisano’s slammed ’65 Chevelle SS convertible

WAGON TRAIN: Al Donofrio’s slick ’66 Malibu wagon

WHEN SECONDS COUNT: Randy Miller’s ’69 Yenko Camaro Factory Street racer

Since 1964, the Chevelle has proven itself to be one of the most versatile vehicle platforms ever produced. Larger than the Camaro yet smaller and lighter than its full-size Impala brothers, the full-frame Chevelle was available in convertible, Super Sport, and economy trim. Drag racers have been abusing Chevelles for years and are now turning corners and taking on challenges that were, until recently, left to Corvettes and Camaros. What’s more amazing is that, in 1970, the Chevelle could be ordered with any engine—from a 155hp 250ci six cylinder to a 450hp 454—just by checking the correct option boxes. CHP is celebrating this phenomenon with a salute to the Chevelle and its cousin, the El Camino.

Check 'em out in the sidebars below.