PDA

View Full Version : GM's small-block V8 turns 50


Gimli
11-01-2005, 07:37 AM
All Hail the SBC!

http://www.autonet.ca/Parts/Components/story.cfm?story=/Parts/Components/2005/10/31/1286411.html

by STEVE MERTL -- Canadian Press posted October 31, 2005

VANCOUVER -- Awash in red ink and losing market share, General Motors Corp. still has had something to celebrate this year -- the 50th anniversary of perhaps the most popular engine in history.

The small-block V-8 motor debuted in the 1955 Chevrolet sedan and will always be identified with Chevy.

But the compact, lightweight but powerful "mouse motor" would eventually proliferate throughout GM's divisions for economic reasons.

More than 90 million small-blocks have been produced.

It's undergone three redesigns but retains its basic layout, including the angle of its cylinder banks, cylinder-bore centres and a camshaft buried in the engine block that works the valves via pushrods when other automakers have gone to overhead-cam designs.

"That initial efficiency and package size has really stood the test well over time and has let us keep evolving this engine for well over 50 years now," says Sam Winegarden, GM's engine development chief.

GM marked the anniversary last summer with touring presentations at automobile shows and vintage car events.

Buffs such as the Florida-based Classic Chevy Club staged their own festivities, including a vintage cruise through the streets of Detroit.

"It's really fun to have the old classics and just get out and cruise around town, enjoy them yourself and share the enjoyment with others," says Canadian Scott Matthews, who owns two vintage Chevys.

The anniversary has a bittersweet quality, too.

The small-block's origins in the era of poodle-skirts and ducktail Elvis hair evoke a time when General Motors and its domestic rivals Ford and Chrysler dominated the North American auto market.

In the early 1960s, one out of every two vehicles sold in America came off a GM assembly line, compared with about one in five today.

When the small-block debuted, imported cars were a noisy nuisance and Japan was better known for cheap transistor radios.

Today imports have close to half the North American market and as in the oil-crisis decade of the 1970s, some observers wonder about the future of V-8 power in an era of buck-a-litre fuel prices.

The small-block V-8 and the cars it powered epitomized the American good life -- gobs of horsepower, effortlessly produced using limitless supplies of fairly cheap gasoline.

Ford was first to offer eight-cylinder power -- once reserved for luxury cars -- to the mass market in its pre-war "flathead" motor, favoured by gangsters like John Dillinger.

After the Second World War, U.S. automakers raced to develop mass-production V-8s. Ford's version arrived first and Chrysler developed its fabled "hemi," now back after decades out of production.

But the Chevy small-block would produce wide, continuous ripples.

It was created in just 15 weeks by Chevy's legendary chief engineer Ed Cole. He capitalized on the latest metallurgy, casting and manufacturing techniques to produce a compact, lightweight but strong package.

The first version in the '55 Chevy displaced only 265 cubic inches (4.3 litres) and produced 162 gross horsepower -- a figure that unlike modern net horsepower ratings doesn't include power lost to engine-driven devices such as the alternator and power-steering pump.

But its displacement quickly grew, with the most popular size being 350 cubic inches (5.7 litres). And with it, power.

The small-block's size made it ideal to shoe-horn into compact 1960s' muscle cars while its strength has allowed it to produce prodigious amounts of horsepower for today's trucks and SUVs.

A 427-cubic-inch (seven-litre) version in the 2006 Corvette puts out 505 net horsepower in stock form. A 300-hp version powers the current Pontiac Grand Prix GXP.

Racers have always been able to coax even more power from small-blocks, which helped its image among ordinary buyers.

"When something is popular and the hot-rodders get to it ... the old slogan used to be win on Sunday, sell on Monday." says Matthews, a Toronto bank mortgage and lending manager. "It was very, very true."

Matthews owns a '55 Chevy hot-rod with a 1969 Corvette small-block in it and a highly collectible stock 1956 Chevy Nomad wagon.

"I have no problem getting some grease under my fingernails, sort of a complete difference from what I do during the day," he says.

"It's a very straightforward motor. It's not that a 10-year-old can take it apart but if you can do things methodically and systematically, things come apart and go back together -- with the right tools, equipment and knowledge -- without a lot of difficulty."

That's also the key to its longevity, says Winegarden.

"Because it's a relatively simple design from a cost perspective, it's pretty hard to beat this thing for what you get," he says.

Many observers thought GM would finally retire the overhead-valve small-block when it introduced the overhead-cam Northstar V-8 in the 1990s, which could rev higher. But the old design, reworked three times in the last 15 years, has had remarkable staying power.

"The small-block revs pretty much where most overhead-cam engines are today until you get to the really high-revving stuff that goes over seven grand," says Winegarden.

Drivers, especially SUV and pickup owners, also prize its torque -- low-speed pickup -- when they're towing boats or trailers.

The 1970s' oil crises and the primitive emission-control technology of the time conspired to strangle all V-8s' power.

They never really recovered in the domestic car market where they once dominated. But computerized fuel and ignition systems that triggered a performance renaissance by the 1990s made small-blocks essential to the surging popularity of GM's hefty trucks and SUVs.

Automakers are using electonics to address the V-8's inherent thirst. GM uses what it calls "displacement on demand," which shuts down one bank of a V-8's cylinders during steady cruising.

"You get the V-8 performance and basically four-cylinder fuel economy when you don't need the V-8 power," says Winegarden.

GM is also looking at other approaches for the small-block, such as gas-electric hybrid V-8s for its trucks, and gasoline direct-injection, which allows very precise fuel metering.

Winegarden says there could be a fifth-generation small-block by the end of this decade.

As for what's in the pipeline now?

"I'm not going to give you a lot there, for obvious reasons," he says. "Let's just say the Corvette never has enough power, so you can draw whatever conclusion you would like from that."

TA^Guy
11-01-2005, 07:15 PM
I love how people (usually uneducated children in crapboxes) say that the pushrod motors are oldschool and no good. But it's obvious it works, so why change it?

GM had the Lotus designed LT5 motor with DOHCs in the early 90s. Not only was it very expensive to produce but the thing was huge and still only displaced 350ci. Not to mention the addition of a extra camshaft, timing chain, etc means more parastic loss. Plus you add more rotating mass higher up, incressing the vehicles center of gravity. Lets also talk aftermarket. The price between pushrod cylinder heads and OHC heads is huge. Not to mention a simple cam swap required two cams, typically meaning twice the price. Sure you don't need to purchase pushrods, but they are what, a whopping $50 at most?

DoubleOZeroGAse
11-01-2005, 07:36 PM
:agree: and it sucks going to a school full of the people who think a 16sec grocery getter is fast and 1.6L DOHC 4-cyl's are God's gift....at least I know the people here who do understand the SBC and real power...hell one of my friends is making an '82 Toyota Carolla Wagon (RWD) into a 350 powered drag car and another friend just put a procharger on her 4th-gen Camaro...God bless General Motors...there's a reason this motor's been around for 50 years! and I hope for another 50....where else can you find a motor, that for less than $2000 (including car and motor, in the Carolla case) can put out over 400hp all day every day? :usa:

jayhawk
11-01-2005, 07:44 PM
I grew up working and tinkering on OHV engines; not really my style anymore (can you TELL??!?). It is impressive that the engine has gone on for this long.

It would have been cool if GM had grown a pair and put stiffer valve springs in and got an extra 1000 RPMs; anyone who's familiar with a 7000 RPM scream from a Dodge knows what I mean.

Me, I like high revving engines, and an engine that redlined at 4500 seemed like such a waste.

DontPassTheFence
11-02-2005, 01:53 AM
Originally posted by jayhawk
I grew up working and tinkering on OHV engines; not really my style anymore (can you TELL??!?). It is impressive that the engine has gone on for this long.

It would have been cool if GM had grown a pair and put stiffer valve springs in and got an extra 1000 RPMs; anyone who's familiar with a 7000 RPM scream from a Dodge knows what I mean.

Me, I like high revving engines, and an engine that redlined at 4500 seemed like such a waste.

I can identify, Jay. My first engine swap was a 2.8L OHV (89 beretta GT) and they are great, but lack the rev-power.

Im not talking about honda b16 engines that dont have any torque until 5 or 6000rpms... I mean the thrill of the rotary engine, really. Ive never worked on one, never owned one, and have only driven one once. (a blue 91 RX7 GTU -> the FC chassis) and it was amazing. My friend let me rev it up to 9k!! 9K! It was breathtaking. Sure, 9K is a bit above the useful powerband, but its an effin' blast to know there exists an engine that can rev that high without blowing up. And the unique sound of the rotary engine from within the cabin also is breathtaking.

/end ricer rant

God bless Wankel and god bless the RX7.

TA^Guy
11-02-2005, 10:31 PM
Originally posted by jayhawk
I grew up working and tinkering on OHV engines; not really my style anymore (can you TELL??!?). It is impressive that the engine has gone on for this long.

It would have been cool if GM had grown a pair and put stiffer valve springs in and got an extra 1000 RPMs; anyone who's familiar with a 7000 RPM scream from a Dodge knows what I mean.

Me, I like high revving engines, and an engine that redlined at 4500 seemed like such a waste.
Wow what are you building? Old big blocks? lol Last time I checked the 6.0 liter LS2 reds at about 6500 rpm. If you ask me not bad for a engine with that large of displacement.

DoubleOZeroGAse
11-03-2005, 07:58 AM
Hell the LS7 in the ZO6 is officially the world's first production pushrod engine to safely and reliably rev to 7000 :D That's a 427cid small block pushrod V8 revving to 7k! Talk about pushing the limits.

jayhawk
11-03-2005, 05:10 PM
Originally posted by TA^Guy
Wow what are you building? Old big blocks? lol Last time I checked the 6.0 liter LS2 reds at about 6500 rpm. If you ask me not bad for a engine with that large of displacement.

Yeah, I worked with engines from the 60's-70's.

See, 6500 is where it should be. Take advantage of the high rpms PLUS the torque.

TA^Guy
11-03-2005, 09:51 PM
Yes motors from the 60-70s era don't rev that high, but then again neither did early 4 cylinder motors.

92CamaroRS
11-07-2005, 09:25 PM
Whats the point in 9k? honestly in a street car what the hell is the point of reving to 9k rpm? If someone can explain that to me, id be happy to listen.


whats wrong with reving to only 4500? sure its low, honestly id like a red line of 5500-6 but 4500 isnt that bad makes for good acceleration without revving the shit out of the motor. here is another tid bit, less rpm=less wear on internals, more rpm= more rpm on internals!

TA^Guy
11-07-2005, 10:09 PM
Originally posted by 92CamaroRS
Whats the point in 9k? honestly in a street car what the hell is the point of reving to 9k rpm? If someone can explain that to me, id be happy to listen.


whats wrong with reving to only 4500? sure its low, honestly id like a red line of 5500-6 but 4500 isnt that bad makes for good acceleration without revving the shit out of the motor. here is another tid bit, less rpm=less wear on internals, more rpm= more rpm on internals!
I kind of agree in a way, and I know your not into sportbikes but hang with me on this.
I agree that lowend torque is used more day to day than high end horsepower. We get to enjoy feeling the power from every redlight and stop sign as to where feeling high end hp required reving the snot out of a car, usually in a high rate of acceleration. Granted we could just slowly accelerate and hold on to each gear until redline, but that would be a little abusive on the car.

Not as much torque as Vtwins, my bike makes more lowend torque than anyone can fully use in street trim. Aroudn townand typical communting I only run my bike up to about 9000rpms as where when I'm on the open road or racing I tach it out to the sound of 14,000rpms.

The higher rpms allow to hold on teh gears with less shifting. the wide rpm range allows the use of a close ratio gearbox so you can get nice top end and not loose much power at the bottom of each gear.