Wikicars - User contributions [en]

Chevrolet Opala

2010-02-02T19:55:04Z

250-S:

[[Image:554 bras opalass abreheader.jpg|right|frame|'''Chevrolet Opala SS''']]
The '''Chevrolet Opala''' was a mid-size car sold by [[General Motors do Brasil]] from 1969 to 1992. It was derived from the German [[Opel Rekord]] and Commodore, but used GM USA sourced engines, two four-cylinder engines: the 151-4 [[GM Iron Duke engine|Iron Duke]] from Pontiac, the Chevrolet 153-4 from [[Chevrolet Nova|Chevy II/Nova]] and the [[Chevrolet Straight-6 engine#Generation 3|six-cylinder 250]] from the current line of North American car/light truck production. GM manufactured about one million units including the Opala sedan, Opala Coupé and the station wagon variation, the Opala Caravan. It was replaced by the [[Chevrolet Omega]] in 1992, also an Opel spinoff. Before this car, Chevrolet only built light trucks and pick-up trucks, so, the Opala was its first passenger car made in Brazil.

It was used by the São Paulo Police for many years. The military dictatorship used the Opala for its agents through the 1970s. Its reliability and easy maintenance made the Opala the choice of many taxi drivers and also popular on racetracks.

Its 250 in³ engine (4.1 L) was used in its replacement, the Chevrolet Omega, but making use of Electronic Fuel Injection, in GLS and CD trims from 1995 to 1998. Some of the components and chassis were used for an exotic car called [[Santa Matilde]].

==Early history==
Installed in Brazil since January 1925, General Motors restricted itself to assemble, and then, manufacturing pick-ups, utilities and trucks until the mid-1960s. Only then was decided to produce its first national Chevrolet.

The options oscillated between the large American cars from the traditional car line, like the Impala, and the lighter and economical models from German subsidiary Opel - Kadett, Olympia, Rekord and Commodore - that came to Brazil imported in small quantities. After hesitating between the small Kadett and the large Rekord/Commodore line, GMB opted for the second one, but later introduced the Kadett too.

On November 23, 1966, in a Press Conference at the Club Atlético Paulistano, in São Paulo, GM announced the start of Project 676, the future Chevrolet Opala.

==Name controversy==
The name Opala, comes from a precious stone, colourless when extracted from the soil, but that acquires multiple tones when exposed to light. It was also commented that it, the merger between [[Opel]] and Impala, as it was derived from the German [[Opel Rekord]], but one of its engines (the 230 in³, and later, 250 in³ [[straight-six]]) came from North American [[Chevrolet Impala]]. Even GM admits that was not set to, when that name - one of six finalists from thousands of suggestions - was disclosed by a journalist. Its rapid acceptance with the general public led to the approval of choice.

==The debut==
At the opening of the 6th São Paulo Auto Show, on November 23, 1968, Opala appeared on a rotating stage stand. Around the novelty, spectacles including counting with the presence of Stirling Moss and several models were enscenated every half hour.

The first model was the four-door sedan, in the trims "Especial" (Standard) and "Luxo" (Luxe). Its attractive lines used the solution of curvy lines from the windscreen to rear fender, a shape that was referred to as "Coke Bottle style", already in use at the time, as it was first shown on 1967 Chevrolet Camaro, 1967 [[Pontiac Firebird]] and 1968 [[Chevrolet Corvette]], but some hints of the upcoming style were already clear on the 1965 [[Chevrolet Impala]] fastback coupé. The round headlamps (not squared, as in the Opel Rekord and Commodore), distinguished an egg crate grille, distinctively Chevrolet style, that separated the Opala from its European Opel syblings and the park/turning lamps, were fitted below, in the front bumper. In the back, a chrome strip with the "Chevrolet" name in black linked in the more expensive trim, the small rectangular tailights, in the extremities of the rear overhang, with the small reverse lights in the rear-bumper. Just above this was the fuel tank cap. The "Opala" badge, was fitted in the rear fenders, and the engine badges - 2500 or 3800 - next to the front doors. The chrome wheelcovers fitted just fine with the whitewall tires.

Both versions came standard with front bench seats (bucket seats weren't available at the beginning of production, but were later adopted) and steering-column shifter. The two models differed in trim levels: reverse lights, fuel tank lock and rear valance chrome strip were available only on "Luxo" model.

==Engine's strength==
Under the hood, that opened backwards, the Opala offered three engine choices: the straight-4 153 in³ (2503 cc), the Pontiac Iron Duke-4 151 in³ (2497 cc) and the straight-6 230 in³ (3764 cc). The trio was of very traditional design, with cast iron cylinder block and head, overhead valves, pushrods and steel pressed rocker arms, whose spherical fulcrum was a proprietary GM's creation -Fuel feed from either one or two barrel carburators.

The Opala engines had been already used for years in the U.S.: the 153 in³ had emerged in the 1961 [[Chevrolet Nova]], becoming the first inline four in Chevy since 1928, and the 230 in³ appeared in the 1963 Impala. The 151 in³ Pontiac Iron Duke was also found on AMC Jeeps and Eagle, and was known for versatility and toughness. Known for its reliability the 153 in³, was used as the corporation standard until the 1980s. The [[straight-six]] later served as a stationary engine, school bus engine and even forklifts.

The larger engine crankshaft bearings had seven supports (five in four cylinders) and the generous, if not even redundant, size of its inner moving parts helped with its durability and exceptional smoothness. The hydraulic valve lifters contributed to that later feature, easying maintenance.

The straight six biggest limitation through the years was poor distribution of air-fuel ratio to the cylinders. Number one and six received the poorest, with higher percentage of air in the mixture, while the central ones tended to get richer mixture, unbalancing the stoichiometric engine efficiency. That bad feature was easily solved by installing a race intake manifold that sported two or three two-barrel carburators, as in Stock Car racing. Only in 1994, with the [[Chevrolet Omega|Omega]] and the multipoint injection, the problem was finally solved.

The performance of Opala 3.8L was actually very pleasing: with a top speed of 102.5 mph and acceleration time from 0 to 60 mph in about 13 seconds, was the fastest Brazilian car of its time, while it was losing the post after a year to the [[Dodge Dart]] whose 318 in³ V8 had all a straight six needed. The two 2.5L did not offer so much brio, but were torquey enough for everyday use. The main complain over the four cylinder engines was about their roughness - so much rogh, that at the time, GM employees called the Four "little Toyota", in allusion to the diesel engine installed other locally made Toyota Bandeirante (local name for the [[Toyota Land Cruiser|Land Cruiser]]).

The two versions, Especial and Luxo, had 3-speed manual [[gearbox]], [[rear wheel drive]], front independent suspension and rear live axle, both with helical springs. In front, the suspension elements were anchored to one side, set in unibody by screws, which only later would be known as subframe. The tires were the first tubeless to be used in a model manufactured in Brazil, and used clutch spring type "Chinese hat", or diaphragmatic spring, which began to popularize in the world.

[[Image:Chevrolet Opala 250-S engine.jpg|right|frame|'''The 250-S Engine''']]
===Engines===
* [[GM Iron Duke engine#External_links|Iron Duke GM L4 151 2.5L motors]]
*151 in³ 4 cylinder (2.5 L) - 94 hp Gross - (1974-1976)
*151 in³ 4 cylinder (2.5 L) Ethanol - 98 hp Gross - (1980-1992)
*151-S in³ 4 cylinder (2.5 L) - 98 hp Gross - (1974-1992)
*153 in³ 4 cylinder (2.5 L) - 80 hp Gross - (1968-1973)
*230 in³ 6 cylinder (3.8 L) - 125 hp Gross - (1968-1971)
*250 in³ 6 cylinder (4.1 L) - 140 hp Gross - (1971-1975)
*250 in³ 6 cylinder (4.1 L) - 148 hp Gross - (1975-1988)
*250 in³ 6 cylinder Ethanol (4.1 L) - 155 hp Gross - (1984-1990)
*250-S in³ 6 cylinder (4.1 L) - 171 hp Gross - (1976-1988)
*250/S in³ 6 cylinder (4.1 L) 118 hp Net (1988-1990)
*250/S in³ 6 cylinder (4.1 L) 121 hp Net (1990-1992)
*250/S in³ 6 cylinder Ethanol (4.1 L) 141 hp Net (1990-1992)

====The 250-S Engine====
When the long duration races restarted in Brazil, in 1973, the Opala found a great competitor, the [[Ford Maverick]], which was powered by an engine whose displacement was almost one liter bigger. It took Bob Sharp and Jan Balder, that gained a second place in the "24 Hours of Interlagos", in August of that year in an Opala, to pressure GMB to field on race tracks a more powerful engine.

By coincidence, engine development manager, Roberto B. Beccardi, was working on this engine hopping up project out of his own initiative, but he did lack impulse from factory and was not obtaining any approval.
This impulse came right from these two pilots.

Thus, in July 1974 GM started to offer the 250-S engine as an option for the Opala 4100. It was slightly different from the version that would be launched two years later: the project of the motor was similar to that of the four cylinders units, did not get a vibration damper and the cooling fan came from the standard 2500, with four blades instead of six.

The Opala was now much faster than the Maverick GT and [[Ford]] did not waste time. It quickly homologated a version with four barrel carburetor, simply called "Quadrijet" in Brazilian parlance, and have no relationship with GM own Rochester Quadrajet carburator, found on GM Corp. various V 8 engines. In the racetracks, the accounting determinative factor for winning was pilots skill and pit organization on the track. The rivals walked side-by-side.

===Transmissions===
*3-speed Manual (steering column shifter)
*4-speed Manual (floor mounted shifter)
*5-speed Manual (floor mounted shifter)
*3-speed Automatic (steering column or floor mounted shifter)
*4-speed Automatic (floor mounted shifter)

==Photos==
<gallery>
Image:Opala69.fte.jpg
Image:1971 SS.jpg
Image:Opala75hc1.jpg
Image:Car7510.jpg
Image:554 bras opalass abre.jpg
Image:Diplomata83pp0.jpg
Image:Diplomata-92.jpg
</gallery>

==See Also==
{{Chevrolet}}

==External links==
* [http://www.opala.com Chevrolet Opala website] in Portuguese
* [http://www2.uol.com.br/bestcars/classicos/opala-1.htm The Opala history] in Portuguese

[[Category:Chevrolet vehicles|Opala]]

File:Chevrolet Opala 250-S engine.jpg

2010-02-02T19:52:41Z

250-S: Opala 250-S Engine

Opala 250-S Engine

Gurgel

2010-02-01T18:06:49Z

250-S:

[[Image:Gurgel.jpg|right|top]]
{{List of {{PAGENAME}} Models}}'''Gurgel''' was the brand of [[Gurgel Veículos]], a Brazilian automobile manufacturer, named for its founder, João do Amaral Gurgel. The company was founded in 1969 and specialized in off-road vehicles, many of which were named after Brazil's native tribes. Early models were fiberglass bodies installed on [[Volkswagen]] [[VW Beetle|Beetle]] (''fusca'') chasses and machinery. Gurgel introduced Brazil's first domestically designed car, the BR-800, but went out of business in the 1990s.

==Important models==
* Gurgel Moplast
* Gurgel Junior
* Gurgel Ipanema
* Gurgel QT (1970-1972)
* Gurgel Xavante XT 1972
* Gurgel Xavante X10
* Gurgel Xavante X11
* Gurgel Xavante X12
* Gurgel Tocantins
* Gurgel Carajás
* Gurgel X15
* Gurgel X20
* Gurgel E500
* Gurgel G800
* Gurgel XEF
* Gurgel BR-800
* Gurgel Supermini
* Gurgel Motomachine
* Gurgel TA-01

==External links==
* [http://gurgelbrasil.com/ Gurgel Brasil]
* [http://www.gurgel800.com.br/ Gurgel 800]
* [http://www2.uol.com.br/bestcars/classicos/gurgel-1.htm Os Carros de Rio Claro] (in Portuguese)
* [http://www.gurgelx15.cjb.net Gurgel X15] & family]

[[Category:Motor vehicle manufacturers of Brazil]]
[[Category:Brazilian automobiles]]
[[Category:Makes]]

{{auto-company-stub}}

File:Gurgel.jpg

2010-02-01T18:05:43Z

250-S: Gurgel logo

Gurgel logo

Puma

2010-02-01T18:03:54Z

250-S:

[[Image:Puma-Logo.jpg|right]] {{List of {{PAGENAME}} Models}}'''Puma''' was a Brazilian specialist car manufacturer who built cars between 1967 and around 1997. High import tariffs effectively closed Brazil during much of this period to foreign-built cars, and the vehicles available to the average Brazilian were limited to those built in Brazil either by foreign manufacturers, such as [[Volkswagen]] and [[General Motors Corporation|General Motors]], who established Brazilian manufacturing plants, and the products of local companies.

The origin of what was to become the Puma was the '''DKW-Malzoni''', built by Rino Malzoni of Matão in São Paulo state from around 1964. Malzoni was a keen auto racer and began building his own competition cars based around a [[DKW]] [[straight-3]] [[two-stroke]] engine with a light, fiberglass-skinned bodyshell. The cars began to sell in quantities larger than he himself could build, and Malzoni founded a company with a group of other auto enthusiasts. Production at first was around 35 cars a year, increasing to more than a hundred within a couple of years.

1967 saw DKW bought out by Volkswagen and the Brazilian production of DKWs ceased. With no DKW engine available, a new car was designed, based around the rear-engined, air-cooled [[Volkswagen Karmann Ghia]] sold in Brazil. The car was named Puma and the company was likewise renamed, and it sold relatively well for a specialist [[sports car]].

A convertible version, the Spyder, was added in around 1970 and cars began to be exported around that date, to other South American countries, North American and Europe. Many of the exported vehicles were [[kit car]]s - actually substantially complete bodyshells, but lacking engine, transmission, axles, wheels and other mechanical parts. All cars sold in Brazil were complete.

Another model, the '''[[Puma GTB]]''', used a front-mounted Chevrolet [[straight-6]]; this model was not exported.

VW stopped production of the Karmann Ghia in Brazil during the mid 1970s, and the car was switched to take from the [[Volkswagen Brasilia]] instead. Pumas began to be assembled in South Africa around this time. Bodywork was restyled in 1977.

The 1980s saw harsh economic times in Brazil, and this hit Puma hard. In 1985, the rights to the Puma were sold; a year later, they were sold again. Production continued in small numbers, but the opening of the Brazilian market to foreign cars in the early 1990s was the final blow,
The last commercialized Puma was a AM4 in 1997.

==External Links==

* http://www.pumacars.co.za

[[Category:Motor vehicle manufacturers of Brazil]]
[[Category:Makes]]

File:Puma-Logo.jpg

2010-02-01T18:03:10Z

250-S: puma mini logo

puma mini logo

File:Kopf gelb neu4.jpg

2010-02-01T17:59:45Z

250-S: Puma logo

Puma logo

Chevrolet Opala

2010-02-01T17:55:39Z

250-S:

[[Image:Images75.jpg|right]]
The '''Chevrolet Opala''' was a mid-size car sold by [[General Motors do Brasil]] from 1969 to 1992. It was derived from the German [[Opel Rekord]] and Commodore, but used GM USA sourced engines, two four-cylinder engines: the 151-4 [[GM Iron Duke engine|Iron Duke]] from Pontiac, the Chevrolet 153-4 from [[Chevrolet Nova|Chevy II/Nova]] and the [[Chevrolet Straight-6 engine#Generation 3|six-cylinder 250]] from the current line of North American car/light truck production. GM manufactured about one million units including the Opala sedan, Opala Coupé and the station wagon variation, the Opala Caravan. It was replaced by the [[Chevrolet Omega]] in 1992, also an Opel spinoff. Before this car, Chevrolet only built light trucks and pick-up trucks, so, the Opala was its first passenger car made in Brazil.

It was used by the São Paulo Police for many years. The military dictatorship used the Opala for its agents through the 1970s. Its reliability and easy maintenance made the Opala the choice of many taxi drivers and also popular on racetracks.

Its 250 in³ engine (4.1 L) was used in its replacement, the Chevrolet Omega, but making use of Electronic Fuel Injection, in GLS and CD trims from 1995 to 1998. Some of the components and chassis were used for an exotic car called [[Santa Matilde]].

==Early history==
Installed in Brazil since January 1925, General Motors restricted itself to assemble, and then, manufacturing pick-ups, utilities and trucks until the mid-1960s. Only then was decided to produce its first national Chevrolet.

The options oscillated between the large American cars from the traditional car line, like the Impala, and the lighter and economical models from German subsidiary Opel - Kadett, Olympia, Rekord and Commodore - that came to Brazil imported in small quantities. After hesitating between the small Kadett and the large Rekord/Commodore line, GMB opted for the second one, but later introduced the Kadett too.

On November 23, 1966, in a Press Conference at the Club Atlético Paulistano, in São Paulo, GM announced the start of Project 676, the future Chevrolet Opala.

==Name controversy==
The name Opala, comes from a precious stone, colourless when extracted from the soil, but that acquires multiple tones when exposed to light. It was also commented that it, the merger between [[Opel]] and Impala, as it was derived from the German [[Opel Rekord]], but one of its engines (the 230 in³, and later, 250 in³ [[straight-six]]) came from North American [[Chevrolet Impala]]. Even GM admits that was not set to, when that name - one of six finalists from thousands of suggestions - was disclosed by a journalist. Its rapid acceptance with the general public led to the approval of choice.

==The debut==
At the opening of the 6th São Paulo Auto Show, on November 23, 1968, Opala appeared on a rotating stage stand. Around the novelty, spectacles including counting with the presence of Stirling Moss and several models were enscenated every half hour.

The first model was the four-door sedan, in the trims "Especial" (Standard) and "Luxo" (Luxe). Its attractive lines used the solution of curvy lines from the windscreen to rear fender, a shape that was referred to as "Coke Bottle style", already in use at the time, as it was first shown on 1967 Chevrolet Camaro, 1967 [[Pontiac Firebird]] and 1968 [[Chevrolet Corvette]], but some hints of the upcoming style were already clear on the 1965 [[Chevrolet Impala]] fastback coupé. The round headlamps (not squared, as in the Opel Rekord and Commodore), distinguished an egg crate grille, distinctively Chevrolet style, that separated the Opala from its European Opel syblings and the park/turning lamps, were fitted below, in the front bumper. In the back, a chrome strip with the "Chevrolet" name in black linked in the more expensive trim, the small rectangular tailights, in the extremities of the rear overhang, with the small reverse lights in the rear-bumper. Just above this was the fuel tank cap. The "Opala" badge, was fitted in the rear fenders, and the engine badges - 2500 or 3800 - next to the front doors. The chrome wheelcovers fitted just fine with the whitewall tires.

Both versions came standard with front bench seats (bucket seats weren't available at the beginning of production, but were later adopted) and steering-column shifter. The two models differed in trim levels: reverse lights, fuel tank lock and rear valance chrome strip were available only on "Luxo" model.

==Engine's strength==
Under the hood, that opened backwards, the Opala offered three engine choices: the straight-4 153 in³ (2503 cc), the Pontiac Iron Duke-4 151 in³ (2497 cc) and the straight-6 230 in³ (3764 cc). The trio was of very traditional design, with cast iron cylinder block and head, overhead valves, pushrods and steel pressed rocker arms, whose spherical fulcrum was a proprietary GM's creation -Fuel feed from either one or two barrel carburators.

The Opala engines had been already used for years in the U.S.: the 153 in³ had emerged in the 1961 [[Chevrolet Nova]], becoming the first inline four in Chevy since 1928, and the 230 in³ appeared in the 1963 Impala. The 151 in³ Pontiac Iron Duke was also found on AMC Jeeps and Eagle, and was known for versatility and toughness. Known for its reliability the 153 in³, was used as the corporation standard until the 1980s. The [[straight-six]] later served as a stationary engine, school bus engine and even forklifts.

The larger engine crankshaft bearings had seven supports (five in four cylinders) and the generous, if not even redundant, size of its inner moving parts helped with its durability and exceptional smoothness. The hydraulic valve lifters contributed to that later feature, easying maintenance.

The straight six biggest limitation through the years was poor distribution of air-fuel ratio to the cylinders. Number one and six received the poorest, with higher percentage of air in the mixture, while the central ones tended to get richer mixture, unbalancing the stoichiometric engine efficiency. That bad feature was easily solved by installing a race intake manifold that sported two or three two-barrel carburators, as in Stock Car racing. Only in 1994, with the [[Chevrolet Omega|Omega]] and the multipoint injection, the problem was finally solved.

The performance of Opala 3.8L was actually very pleasing: with a top speed of 102.5 mph and acceleration time from 0 to 60 mph in about 13 seconds, was the fastest Brazilian car of its time, while it was losing the post after a year to the [[Dodge Dart]] whose 318 in³ V8 had all a straight six needed. The two 2.5L did not offer so much brio, but were torquey enough for everyday use. The main complain over the four cylinder engines was about their roughness - so much rogh, that at the time, GM employees called the Four "little Toyota", in allusion to the diesel engine installed other locally made Toyota Bandeirante (local name for the [[Land Cruiser]]).

The two versions, Especial and Luxo, had 3-speed manual [[gearbox]], [[rear wheel drive]], front independent suspension and rear live axle, both with helical springs. In front, the suspension elements were anchored to one side, set in unibody by screws, which only later would be known as subframe. The tires were the first [[tubeless]] to be used in a model manufactured in Brazil, and used clutch spring type "Chinese hat", or diaphragmatic spring, which began to popularize in the world.

===Engines===
* [[GM Iron Duke engine#External_links|Iron Duke GM L4 151 2.5L motors]]
*151 in³ 4 cylinder (2.5 L) - 94 hp Gross - (1974-1976)
*151 in³ 4 cylinder (2.5 L) Ethanol - 98 hp Gross - (1980-1992)
*151-S in³ 4 cylinder (2.5 L) - 98 hp Gross - (1974-1992)
*153 in³ 4 cylinder (2.5 L) - 80 hp Gross - (1968-1973)
*230 in³ 6 cylinder (3.8 L) - 125 hp Gross - (1968-1971)
*250 in³ 6 cylinder (4.1 L) - 140 hp Gross - (1971-1975)
*250 in³ 6 cylinder (4.1 L) - 148 hp Gross - (1975-1988)
*250 in³ 6 cylinder Ethanol (4.1 L) - 155 hp Gross - (1984-1990)
*250-S in³ 6 cylinder (4.1 L) - 171 hp Gross - (1976-1988)
*250/S in³ 6 cylinder (4.1 L) 118 hp Net (1988-1990)
*250/S in³ 6 cylinder (4.1 L) 121 hp Net (1990-1992)
*250/S in³ 6 cylinder Ethanol (4.1 L) 141 hp Net (1990-1992)

====The 250-S Engine====
When the long duration races restarted in Brazil, in 1973, the Opala found a great competitor, the [[Ford Maverick]], which was powered by an engine whose displacement was almost one liter bigger. It took Bob Sharp and Jan Balder, that gained a second place in the "24 Hours of Interlagos", in August of that year in an Opala, to pressure GMB to field on race tracks a more powerful engine.

By coincidence, engine development manager, Roberto B. Beccardi, was working on this engine hopping up project out of his own initiative, but he did lack impulse from factory and was not obtaining any approval.
This impulse came right from these two pilots.

Thus, in July 1974 GM started to offer the 250-S engine as an option for the Opala 4100. It was slightly different from the version that would be launched two years later: the project of the motor was similar to that of the four cylinders units, did not get a vibration damper and the cooling fan came from the standard 2500, with four blades instead of six.

The Opala was now much faster than the Maverick GT and [[Ford]] did not waste time. It quickly homologated a version with four barrel carburetor, simply called "Quadrijet" in Brazilian parlance, and have no relationship with GM own Rochester Quadrajet carburator, found on GM Corp. various V 8 engines. In the racetracks, the accounting determinative factor for winning was pilots skill and pit organization on the track. The rivals walked side-by-side.

===Transmissions===
*3-speed Manual (steering column shifter)
*4-speed Manual (floor mounted shifter)
*5-speed Manual (floor mounted shifter)
*3-speed Automatic (steering column or floor mounted shifter)
*4-speed Automatic (floor mounted shifter)

==Photos==
<gallery>
Image:Opala69.fte.jpg
Image:1971 SS.jpg
Image:Opala75hc1.jpg
Image:Car7510.jpg
Image:554 bras opalass abre.jpg
Image:Diplomata83pp0.jpg
Image:Diplomata-92.jpg
</gallery>

==External links==
* [http://www.opala.com Chevrolet Opala website] in Portuguese
* [http://www2.uol.com.br/bestcars/classicos/opala-1.htm The Opala history] in Portuguese

[[Category:Chevrolet vehicles|Opala]]

Chevrolet Opala

2010-02-01T17:54:08Z

250-S:

[[Image:Images75.jpg]]
The '''Chevrolet Opala''' was a mid-size car sold by [[General Motors do Brasil]] from 1969 to 1992. It was derived from the German [[Opel Rekord]] and Commodore, but used GM USA sourced engines, two four-cylinder engines: the 151-4 [[GM Iron Duke engine|Iron Duke]] from Pontiac, the Chevrolet 153-4 from [[Chevrolet Nova|Chevy II/Nova]] and the [[Chevrolet Straight-6 engine#Generation 3|six-cylinder 250]] from the current line of North American car/light truck production. GM manufactured about one million units including the Opala sedan, Opala Coupé and the station wagon variation, the Opala Caravan. It was replaced by the [[Chevrolet Omega]] in 1992, also an Opel spinoff. Before this car, Chevrolet only built light trucks and pick-up trucks, so, the Opala was its first passenger car made in Brazil.

It was used by the São Paulo Police for many years. The military dictatorship used the Opala for its agents through the 1970s. Its reliability and easy maintenance made the Opala the choice of many taxi drivers and also popular on racetracks.

Its 250 in³ engine (4.1 L) was used in its replacement, the Chevrolet Omega, but making use of Electronic Fuel Injection, in GLS and CD trims from 1995 to 1998. Some of the components and chassis were used for an exotic car called [[Santa Matilde]].

==Early history==
Installed in Brazil since January 1925, General Motors restricted itself to assemble, and then, manufacturing pick-ups, utilities and trucks until the mid-1960s. Only then was decided to produce its first national Chevrolet.

The options oscillated between the large American cars from the traditional car line, like the Impala, and the lighter and economical models from German subsidiary Opel - Kadett, Olympia, Rekord and Commodore - that came to Brazil imported in small quantities. After hesitating between the small Kadett and the large Rekord/Commodore line, GMB opted for the second one, but later introduced the Kadett too.

On November 23, 1966, in a Press Conference at the Club Atlético Paulistano, in São Paulo, GM announced the start of Project 676, the future Chevrolet Opala.

==Name controversy==
The name Opala, comes from a precious stone, colourless when extracted from the soil, but that acquires multiple tones when exposed to light. It was also commented that it, the merger between [[Opel]] and Impala, as it was derived from the German [[Opel Rekord]], but one of its engines (the 230 in³, and later, 250 in³ [[straight-six]]) came from North American [[Chevrolet Impala]]. Even GM admits that was not set to, when that name - one of six finalists from thousands of suggestions - was disclosed by a journalist. Its rapid acceptance with the general public led to the approval of choice.

==The debut==
At the opening of the 6th São Paulo Auto Show, on November 23, 1968, Opala appeared on a rotating stage stand. Around the novelty, spectacles including counting with the presence of Stirling Moss and several models were enscenated every half hour.

The first model was the four-door sedan, in the trims "Especial" (Standard) and "Luxo" (Luxe). Its attractive lines used the solution of curvy lines from the windscreen to rear fender, a shape that was referred to as "Coke Bottle style", already in use at the time, as it was first shown on 1967 Chevrolet Camaro, 1967 [[Pontiac Firebird]] and 1968 [[Chevrolet Corvette]], but some hints of the upcoming style were already clear on the 1965 [[Chevrolet Impala]] fastback coupé. The round headlamps (not squared, as in the Opel Rekord and Commodore), distinguished an egg crate grille, distinctively Chevrolet style, that separated the Opala from its European Opel syblings and the park/turning lamps, were fitted below, in the front bumper. In the back, a chrome strip with the "Chevrolet" name in black linked in the more expensive trim, the small rectangular tailights, in the extremities of the rear overhang, with the small reverse lights in the rear-bumper. Just above this was the fuel tank cap. The "Opala" badge, was fitted in the rear fenders, and the engine badges - 2500 or 3800 - next to the front doors. The chrome wheelcovers fitted just fine with the whitewall tires.

Both versions came standard with front bench seats (bucket seats weren't available at the beginning of production, but were later adopted) and steering-column shifter. The two models differed in trim levels: reverse lights, fuel tank lock and rear valance chrome strip were available only on "Luxo" model.

==Engine's strength==
Under the hood, that opened backwards, the Opala offered three engine choices: the straight-4 153 in³ (2503 cc), the Pontiac Iron Duke-4 151 in³ (2497 cc) and the straight-6 230 in³ (3764 cc). The trio was of very traditional design, with cast iron cylinder block and head, overhead valves, pushrods and steel pressed rocker arms, whose spherical fulcrum was a proprietary GM's creation -Fuel feed from either one or two barrel carburators.

The Opala engines had been already used for years in the U.S.: the 153 in³ had emerged in the 1961 [[Chevrolet Nova]], becoming the first inline four in Chevy since 1928, and the 230 in³ appeared in the 1963 Impala. The 151 in³ Pontiac Iron Duke was also found on AMC Jeeps and Eagle, and was known for versatility and toughness. Known for its reliability the 153 in³, was used as the corporation standard until the 1980s. The [[straight-six]] later served as a stationary engine, school bus engine and even forklifts.

The larger engine crankshaft bearings had seven supports (five in four cylinders) and the generous, if not even redundant, size of its inner moving parts helped with its durability and exceptional smoothness. The hydraulic valve lifters contributed to that later feature, easying maintenance.

The straight six biggest limitation through the years was poor distribution of air-fuel ratio to the cylinders. Number one and six received the poorest, with higher percentage of air in the mixture, while the central ones tended to get richer mixture, unbalancing the stoichiometric engine efficiency. That bad feature was easily solved by installing a race intake manifold that sported two or three two-barrel carburators, as in Stock Car racing. Only in 1994, with the [[Chevrolet Omega|Omega]] and the multipoint injection, the problem was finally solved.

The performance of Opala 3.8L was actually very pleasing: with a top speed of 102.5 mph and acceleration time from 0 to 60 mph in about 13 seconds, was the fastest Brazilian car of its time, while it was losing the post after a year to the [[Dodge Dart]] whose 318 in³ V8 had all a straight six needed. The two 2.5L did not offer so much brio, but were torquey enough for everyday use. The main complain over the four cylinder engines was about their roughness - so much rogh, that at the time, GM employees called the Four "little Toyota", in allusion to the diesel engine installed other locally made Toyota Bandeirante (local name for the [[Land Cruiser]]).

The two versions, Especial and Luxo, had 3-speed manual [[gearbox]], [[rear wheel drive]], front independent suspension and rear live axle, both with helical springs. In front, the suspension elements were anchored to one side, set in unibody by screws, which only later would be known as subframe. The tires were the first [[tubeless]] to be used in a model manufactured in Brazil, and used clutch spring type "Chinese hat", or diaphragmatic spring, which began to popularize in the world.

===Engines===
* [[GM Iron Duke engine#External_links|Iron Duke GM L4 151 2.5L motors]]
*151 in³ 4 cylinder (2.5 L) - 94 hp Gross - (1974-1976)
*151 in³ 4 cylinder (2.5 L) Ethanol - 98 hp Gross - (1980-1992)
*151-S in³ 4 cylinder (2.5 L) - 98 hp Gross - (1974-1992)
*153 in³ 4 cylinder (2.5 L) - 80 hp Gross - (1968-1973)
*230 in³ 6 cylinder (3.8 L) - 125 hp Gross - (1968-1971)
*250 in³ 6 cylinder (4.1 L) - 140 hp Gross - (1971-1975)
*250 in³ 6 cylinder (4.1 L) - 148 hp Gross - (1975-1988)
*250 in³ 6 cylinder Ethanol (4.1 L) - 155 hp Gross - (1984-1990)
*250-S in³ 6 cylinder (4.1 L) - 171 hp Gross - (1976-1988)
*250/S in³ 6 cylinder (4.1 L) 118 hp Net (1988-1990)
*250/S in³ 6 cylinder (4.1 L) 121 hp Net (1990-1992)
*250/S in³ 6 cylinder Ethanol (4.1 L) 141 hp Net (1990-1992)

====The 250-S Engine====
When the long duration races restarted in Brazil, in 1973, the Opala found a great competitor, the [[Ford Maverick]], which was powered by an engine whose displacement was almost one liter bigger. It took Bob Sharp and Jan Balder, that gained a second place in the "24 Hours of Interlagos", in August of that year in an Opala, to pressure GMB to field on race tracks a more powerful engine.

By coincidence, engine development manager, Roberto B. Beccardi, was working on this engine hopping up project out of his own initiative, but he did lack impulse from factory and was not obtaining any approval.
This impulse came right from these two pilots.

Thus, in July 1974 GM started to offer the 250-S engine as an option for the Opala 4100. It was slightly different from the version that would be launched two years later: the project of the motor was similar to that of the four cylinders units, did not get a vibration damper and the cooling fan came from the standard 2500, with four blades instead of six.

The Opala was now much faster than the Maverick GT and [[Ford]] did not waste time. It quickly homologated a version with four barrel carburetor, simply called "Quadrijet" in Brazilian parlance, and have no relationship with GM own Rochester Quadrajet carburator, found on GM Corp. various V 8 engines. In the racetracks, the accounting determinative factor for winning was pilots skill and pit organization on the track. The rivals walked side-by-side.

===Transmissions===
*3-speed Manual (steering column shifter)
*4-speed Manual (floor mounted shifter)
*5-speed Manual (floor mounted shifter)
*3-speed Automatic (steering column or floor mounted shifter)
*4-speed Automatic (floor mounted shifter)

==Photos==
<gallery>
Image:Opala69.fte.jpg
Image:1971 SS.jpg
Image:Opala75hc1.jpg
Image:Car7510.jpg
Image:554 bras opalass abre.jpg
Image:Diplomata83pp0.jpg
Image:Diplomata-92.jpg
</gallery>

==External links==
* [http://www.opala.com Chevrolet Opala website] in Portuguese
* [http://www2.uol.com.br/bestcars/classicos/opala-1.htm The Opala history] in Portuguese

[[Category:Chevrolet vehicles|Opala]]

File:Images75.jpg

2010-02-01T17:53:08Z

250-S: Opala 75

Opala 75

File:Diplomata-92.jpg

2010-02-01T17:48:53Z

250-S: 1992 Diplomata

1992 Diplomata

File:Diplomata83pp0.jpg

2010-02-01T17:48:27Z

250-S: Diplomata 1983

Diplomata 1983

File:554 bras opalass abre.jpg

2010-02-01T17:47:41Z

250-S:

File:Car7510.jpg

2010-02-01T17:46:15Z

250-S: Caravan 76

Caravan 76

File:Opala75hc1.jpg

2010-02-01T17:45:31Z

250-S: Comodoro 75

Comodoro 75

File:1971 SS.jpg

2010-02-01T17:44:24Z

250-S: Opala SS 1971

Opala SS 1971

Chevrolet Opala

2010-02-01T17:34:19Z

250-S:

[[Image:Opala69.fte.jpg|right|200px]]
The '''Chevrolet Opala''' was a mid-size car sold by [[General Motors do Brasil]] from 1969 to 1992. It was derived from the German [[Opel Rekord]] and Commodore, but used GM USA sourced engines, two four-cylinder engines: the 151-4 [[GM Iron Duke engine|Iron Duke]] from Pontiac, the Chevrolet 153-4 from [[Chevrolet Nova|Chevy II/Nova]] and the [[Chevrolet Straight-6 engine#Generation 3|six-cylinder 250]] from the current line of North American car/light truck production. GM manufactured about one million units including the Opala sedan, Opala Coupé and the station wagon variation, the Opala Caravan. It was replaced by the [[Chevrolet Omega]] in 1992, also an Opel spinoff. Before this car, Chevrolet only built light trucks and pick-up trucks, so, the Opala was its first passenger car made in Brazil.

It was used by the São Paulo Police for many years. The military dictatorship used the Opala for its agents through the 1970s. Its reliability and easy maintenance made the Opala the choice of many taxi drivers and also popular on racetracks.

Its 250 in³ engine (4.1 L) was used in its replacement, the Chevrolet Omega, but making use of Electronic Fuel Injection, in GLS and CD trims from 1995 to 1998. Some of the components and chassis were used for an exotic car called [[Santa Matilde]].

==Early history==
Installed in Brazil since January 1925, General Motors restricted itself to assemble, and then, manufacturing pick-ups, utilities and trucks until the mid-1960s. Only then was decided to produce its first national Chevrolet.

The options oscillated between the large American cars from the traditional car line, like the Impala, and the lighter and economical models from German subsidiary Opel - Kadett, Olympia, Rekord and Commodore - that came to Brazil imported in small quantities. After hesitating between the small Kadett and the large Rekord/Commodore line, GMB opted for the second one, but later introduced the Kadett too.

On November 23, 1966, in a Press Conference at the Club Atlético Paulistano, in São Paulo, GM announced the start of Project 676, the future Chevrolet Opala.

==Name controversy==
The name Opala, comes from a precious stone, colourless when extracted from the soil, but that acquires multiple tones when exposed to light. It was also commented that it, the merger between [[Opel]] and Impala, as it was derived from the German [[Opel Rekord]], but one of its engines (the 230 in³, and later, 250 in³ [[straight-six]]) came from North American [[Chevrolet Impala]]. Even GM admits that was not set to, when that name - one of six finalists from thousands of suggestions - was disclosed by a journalist. Its rapid acceptance with the general public led to the approval of choice.

==The debut==
At the opening of the 6th São Paulo Auto Show, on November 23, 1968, Opala appeared on a rotating stage stand. Around the novelty, spectacles including counting with the presence of Stirling Moss and several models were enscenated every half hour.

The first model was the four-door sedan, in the trims "Especial" (Standard) and "Luxo" (Luxe). Its attractive lines used the solution of curvy lines from the windscreen to rear fender, a shape that was referred to as "Coke Bottle style", already in use at the time, as it was first shown on 1967 Chevrolet Camaro, 1967 [[Pontiac Firebird]] and 1968 [[Chevrolet Corvette]], but some hints of the upcoming style were already clear on the 1965 [[Chevrolet Impala]] fastback coupé. The round headlamps (not squared, as in the Opel Rekord and Commodore), distinguished an egg crate grille, distinctively Chevrolet style, that separated the Opala from its European Opel syblings and the park/turning lamps, were fitted below, in the front bumper. In the back, a chrome strip with the "Chevrolet" name in black linked in the more expensive trim, the small rectangular tailights, in the extremities of the rear overhang, with the small reverse lights in the rear-bumper. Just above this was the fuel tank cap. The "Opala" badge, was fitted in the rear fenders, and the engine badges - 2500 or 3800 - next to the front doors. The chrome wheelcovers fitted just fine with the whitewall tires.

Both versions came standard with front bench seats (bucket seats weren't available at the beginning of production, but were later adopted) and steering-column shifter. The two models differed in trim levels: reverse lights, fuel tank lock and rear valance chrome strip were available only on "Luxo" model.

==Engine's strength==
Under the hood, that opened backwards, the Opala offered three engine choices: the straight-4 153 in³ (2503 cc), the Pontiac Iron Duke-4 151 in³ (2497 cc) and the straight-6 230 in³ (3764 cc). The trio was of very traditional design, with cast iron cylinder block and head, overhead valves, pushrods and steel pressed rocker arms, whose spherical fulcrum was a proprietary GM's creation -Fuel feed from either one or two barrel carburators.

The Opala engines had been already used for years in the U.S.: the 153 in³ had emerged in the 1961 [[Chevrolet Nova]], becoming the first inline four in Chevy since 1928, and the 230 in³ appeared in the 1963 Impala. The 151 in³ Pontiac Iron Duke was also found on AMC Jeeps and Eagle, and was known for versatility and toughness. Known for its reliability the 153 in³, was used as the corporation standard until the 1980s. The [[straight-six]] later served as a stationary engine, school bus engine and even forklifts.

The larger engine crankshaft bearings had seven supports (five in four cylinders) and the generous, if not even redundant, size of its inner moving parts helped with its durability and exceptional smoothness. The hydraulic valve lifters contributed to that later feature, easying maintenance.

The straight six biggest limitation through the years was poor distribution of air-fuel ratio to the cylinders. Number one and six received the poorest, with higher percentage of air in the mixture, while the central ones tended to get richer mixture, unbalancing the stoichiometric engine efficiency. That bad feature was easily solved by installing a race intake manifold that sported two or three two-barrel carburators, as in Stock Car racing. Only in 1994, with the [[Chevrolet Omega|Omega]] and the multipoint injection, the problem was finally solved.

The performance of Opala 3.8L was actually very pleasing: with a top speed of 102.5 mph and acceleration time from 0 to 60 mph in about 13 seconds, was the fastest Brazilian car of its time, while it was losing the post after a year to the [[Dodge Dart]] whose 318 in³ V8 had all a straight six needed. The two 2.5L did not offer so much brio, but were torquey enough for everyday use. The main complain over the four cylinder engines was about their roughness - so much rogh, that at the time, GM employees called the Four "little Toyota", in allusion to the diesel engine installed other locally made Toyota Bandeirante (local name for the [[Land Cruiser]]).

The two versions, Especial and Luxo, had 3-speed manual [[gearbox]], [[rear wheel drive]], front independent suspension and rear live axle, both with helical springs. In front, the suspension elements were anchored to one side, set in unibody by screws, which only later would be known as subframe. The tires were the first [[tubeless]] to be used in a model manufactured in Brazil, and used clutch spring type "Chinese hat", or diaphragmatic spring, which began to popularize in the world.

===Engines===
* [[GM Iron Duke engine#External_links|Iron Duke GM L4 151 2.5L motors]]
*151 in³ 4 cylinder (2.5 L) - 94 hp Gross - (1974-1976)
*151 in³ 4 cylinder (2.5 L) Ethanol - 98 hp Gross - (1980-1992)
*151-S in³ 4 cylinder (2.5 L) - 98 hp Gross - (1974-1992)
*153 in³ 4 cylinder (2.5 L) - 80 hp Gross - (1968-1973)
*230 in³ 6 cylinder (3.8 L) - 125 hp Gross - (1968-1971)
*250 in³ 6 cylinder (4.1 L) - 140 hp Gross - (1971-1975)
*250 in³ 6 cylinder (4.1 L) - 148 hp Gross - (1975-1988)
*250 in³ 6 cylinder Ethanol (4.1 L) - 155 hp Gross - (1984-1990)
*250-S in³ 6 cylinder (4.1 L) - 171 hp Gross - (1976-1988)
*250/S in³ 6 cylinder (4.1 L) 118 hp Net (1988-1990)
*250/S in³ 6 cylinder (4.1 L) 121 hp Net (1990-1992)
*250/S in³ 6 cylinder Ethanol (4.1 L) 141 hp Net (1990-1992)

====The 250-S Engine====
When the long duration races restarted in Brazil, in 1973, the Opala found a great competitor, the [[Ford Maverick]], which was powered by an engine whose displacement was almost one liter bigger. It took Bob Sharp and Jan Balder, that gained a second place in the "24 Hours of Interlagos", in August of that year in an Opala, to pressure GMB to field on race tracks a more powerful engine.

By coincidence, engine development manager, Roberto B. Beccardi, was working on this engine hopping up project out of his own initiative, but he did lack impulse from factory and was not obtaining any approval.
This impulse came right from these two pilots.

Thus, in July 1974 GM started to offer the 250-S engine as an option for the Opala 4100. It was slightly different from the version that would be launched two years later: the project of the motor was similar to that of the four cylinders units, did not get a vibration damper and the cooling fan came from the standard 2500, with four blades instead of six.

The Opala was now much faster than the Maverick GT and [[Ford]] did not waste time. It quickly homologated a version with four barrel carburetor, simply called "Quadrijet" in Brazilian parlance, and have no relationship with GM own Rochester Quadrajet carburator, found on GM Corp. various V 8 engines. In the racetracks, the accounting determinative factor for winning was pilots skill and pit organization on the track. The rivals walked side-by-side.

===Transmissions===
*3-speed Manual (steering column shifter)
*4-speed Manual (floor mounted shifter)
*5-speed Manual (floor mounted shifter)
*3-speed Automatic (steering column or floor mounted shifter)
*4-speed Automatic (floor mounted shifter)

==External links==
* [http://www.opala.com Chevrolet Opala website] in Portuguese
* [http://www2.uol.com.br/bestcars/classicos/opala-1.htm The Opala history] in Portuguese

[[Category:Chevrolet vehicles|Opala]]

Chevrolet Opala

2010-02-01T17:31:38Z

250-S:

[[Image:Opala69.fte.jpg|250px]]
The '''Chevrolet Opala''' was a mid-size car sold by [[General Motors do Brasil]] from 1969 to 1992. It was derived from the German [[Opel Rekord]] and Commodore, but used GM USA sourced engines, two four-cylinder engines: the 151-4 [[GM Iron Duke engine|Iron Duke]] from Pontiac, the Chevrolet 153-4 from [[Chevrolet Nova|Chevy II/Nova]] and the [[Chevrolet Straight-6 engine#Generation 3|six-cylinder 250]] from the current line of North American car/light truck production. GM manufactured about one million units including the Opala sedan, Opala Coupé and the station wagon variation, the Opala Caravan. It was replaced by the [[Chevrolet Omega]] in 1992, also an Opel spinoff. Before this car, Chevrolet only built light trucks and pick-up trucks, so, the Opala was its first passenger car made in Brazil.

It was used by the São Paulo Police for many years. The military dictatorship used the Opala for its agents through the 1970s. Its reliability and easy maintenance made the Opala the choice of many taxi drivers and also popular on racetracks.

Its 250 in³ engine (4.1 L) was used in its replacement, the Chevrolet Omega, but making use of Electronic Fuel Injection, in GLS and CD trims from 1995 to 1998. Some of the components and chassis were used for an exotic car called [[Santa Matilde]].

==Early history==
Installed in Brazil since January 1925, General Motors restricted itself to assemble, and then, manufacturing pick-ups, utilities and trucks until the mid-1960s. Only then was decided to produce its first national Chevrolet.

The options oscillated between the large American cars from the traditional car line, like the Impala, and the lighter and economical models from German subsidiary Opel - Kadett, Olympia, Rekord and Commodore - that came to Brazil imported in small quantities. After hesitating between the small Kadett and the large Rekord/Commodore line, GMB opted for the second one, but later introduced the Kadett too.

On November 23, 1966, in a Press Conference at the Club Atlético Paulistano, in São Paulo, GM announced the start of Project 676, the future Chevrolet Opala.

==Name controversy==
The name Opala, comes from a precious stone, colourless when extracted from the soil, but that acquires multiple tones when exposed to light. It was also commented that it, the merger between [[Opel]] and Impala, as it was derived from the German [[Opel Rekord]], but one of its engines (the 230 in³, and later, 250 in³ [[straight-six]]) came from North American [[Chevrolet Impala]]. Even GM admits that was not set to, when that name - one of six finalists from thousands of suggestions - was disclosed by a journalist. Its rapid acceptance with the general public led to the approval of choice.

==The debut==
At the opening of the 6th São Paulo Auto Show, on November 23, 1968, Opala appeared on a rotating stage stand. Around the novelty, spectacles including counting with the presence of Stirling Moss and several models were enscenated every half hour.

The first model was the four-door sedan, in the trims "Especial" (Standard) and "Luxo" (Luxe). Its attractive lines used the solution of curvy lines from the windscreen to rear fender, a shape that was referred to as "Coke Bottle style", already in use at the time, as it was first shown on 1967 Chevrolet Camaro, 1967 [[Pontiac Firebird]] and 1968 [[Chevrolet Corvette]], but some hints of the upcoming style were already clear on the 1965 [[Chevrolet Impala]] fastback coupé. The round headlamps (not squared, as in the Opel Rekord and Commodore), distinguished an egg crate grille, distinctively Chevrolet style, that separated the Opala from its European Opel syblings and the park/turning lamps, were fitted below, in the front bumper. In the back, a chrome strip with the "Chevrolet" name in black linked in the more expensive trim, the small rectangular tailights, in the extremities of the rear overhang, with the small reverse lights in the rear-bumper. Just above this was the fuel tank cap. The "Opala" badge, was fitted in the rear fenders, and the engine badges - 2500 or 3800 - next to the front doors. The chrome wheelcovers fitted just fine with the whitewall tires.

Both versions came standard with front bench seats (bucket seats weren't available at the beginning of production, but were later adopted) and steering-column shifter. The two models differed in trim levels: reverse lights, fuel tank lock and rear valance chrome strip were available only on "Luxo" model.

==Engine's strength==
Under the hood, that opened backwards, the Opala offered three engine choices: the straight-4 153 in³ (2503 cc), the Pontiac Iron Duke-4 151 in³ (2497 cc) and the straight-6 230 in³ (3764 cc). The trio was of very traditional design, with cast iron cylinder block and head, overhead valves, pushrods and steel pressed rocker arms, whose spherical fulcrum was a proprietary GM's creation -Fuel feed from either one or two barrel carburators.

The Opala engines had been already used for years in the U.S.: the 153 in³ had emerged in the 1961 [[Chevrolet Nova]], becoming the first inline four in Chevy since 1928, and the 230 in³ appeared in the 1963 Impala. The 151 in³ Pontiac Iron Duke was also found on AMC Jeeps and Eagle, and was known for versatility and toughness. Known for its reliability the 153 in³, was used as the corporation standard until the 1980s. The [[straight-six]] later served as a stationary engine, school bus engine and even forklifts.

The larger engine crankshaft bearings had seven supports (five in four cylinders) and the generous, if not even redundant, size of its inner moving parts helped with its durability and exceptional smoothness. The hydraulic valve lifters contributed to that later feature, easying maintenance.

The straight six biggest limitation through the years was poor distribution of air-fuel ratio to the cylinders. Number one and six received the poorest, with higher percentage of air in the mixture, while the central ones tended to get richer mixture, unbalancing the stoichiometric engine efficiency. That bad feature was easily solved by installing a race intake manifold that sported two or three two-barrel carburators, as in Stock Car racing. Only in 1994, with the [[Chevrolet Omega|Omega]] and the multipoint injection, the problem was finally solved.

The performance of Opala 3.8L was actually very pleasing: with a top speed of 102.5 mph and acceleration time from 0 to 60 mph in about 13 seconds, was the fastest Brazilian car of its time, while it was losing the post after a year to the [[Dodge Dart]] whose 318 in³ V8 had all a straight six needed. The two 2.5L did not offer so much brio, but were torquey enough for everyday use. The main complain over the four cylinder engines was about their roughness - so much rogh, that at the time, GM employees called the Four "little Toyota", in allusion to the diesel engine installed other locally made Toyota Bandeirante (local name for the [[Land Cruiser]]).

The two versions, Especial and Luxo, had 3-speed manual [[gearbox]], [[rear wheel drive]], front independent suspension and rear live axle, both with helical springs. In front, the suspension elements were anchored to one side, set in unibody by screws, which only later would be known as subframe. The tires were the first [[tubeless]] to be used in a model manufactured in Brazil, and used clutch spring type "Chinese hat", or diaphragmatic spring, which began to popularize in the world.

===Engines===
* [[GM Iron Duke engine#External_links|Iron Duke GM L4 151 2.5L motors]]
*151 in³ 4 cylinder (2.5 L) - 94 hp Gross - (1974-1976)
*151 in³ 4 cylinder (2.5 L) Ethanol - 98 hp Gross - (1980-1992)
*151-S in³ 4 cylinder (2.5 L) - 98 hp Gross - (1974-1992)
*153 in³ 4 cylinder (2.5 L) - 80 hp Gross - (1968-1973)
*230 in³ 6 cylinder (3.8 L) - 125 hp Gross - (1968-1971)
*250 in³ 6 cylinder (4.1 L) - 140 hp Gross - (1971-1975)
*250 in³ 6 cylinder (4.1 L) - 148 hp Gross - (1975-1988)
*250 in³ 6 cylinder Ethanol (4.1 L) - 155 hp Gross - (1984-1990)
*250-S in³ 6 cylinder (4.1 L) - 171 hp Gross - (1976-1988)
*250/S in³ 6 cylinder (4.1 L) 118 hp Net (1988-1990)
*250/S in³ 6 cylinder (4.1 L) 121 hp Net (1990-1992)
*250/S in³ 6 cylinder Ethanol (4.1 L) 141 hp Net (1990-1992)

====The 250-S Engine====
When the long duration races restarted in Brazil, in 1973, the Opala found a great competitor, the [[Ford Maverick]], which was powered by an engine whose displacement was almost one liter bigger. It took Bob Sharp and Jan Balder, that gained a second place in the "24 Hours of Interlagos", in August of that year in an Opala, to pressure GMB to field on race tracks a more powerful engine.

By coincidence, engine development manager, Roberto B. Beccardi, was working on this engine hopping up project out of his own initiative, but he did lack impulse from factory and was not obtaining any approval.
This impulse came right from these two pilots.

Thus, in July 1974 GM started to offer the 250-S engine as an option for the Opala 4100. It was slightly different from the version that would be launched two years later: the project of the motor was similar to that of the four cylinders units, did not get a vibration damper and the cooling fan came from the standard 2500, with four blades instead of six.

The Opala was now much faster than the Maverick GT and [[Ford]] did not waste time. It quickly homologated a version with four barrel carburetor, simply called "Quadrijet" in Brazilian parlance, and have no relationship with GM own Rochester Quadrajet carburator, found on GM Corp. various V 8 engines. In the racetracks, the accounting determinative factor for winning was pilots skill and pit organization on the track. The rivals walked side-by-side.

===Transmissions===
*3-speed Manual (steering column shifter)
*4-speed Manual (floor mounted shifter)
*5-speed Manual (floor mounted shifter)
*3-speed Automatic (steering column or floor mounted shifter)
*4-speed Automatic (floor mounted shifter)

==External links==
* [http://www.opala.com Chevrolet Opala website] in Portuguese
* [http://www2.uol.com.br/bestcars/classicos/opala-1.htm The Opala history] in Portuguese

[[Category:Chevrolet vehicles|Opala]]

File:Opala69.fte.jpg

2010-02-01T17:22:55Z

250-S: Opala 1969

Opala 1969