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LS7 427 (7-L) Chevrolet Corvette Z06 and Camaro Z/28 Engine: Most Powerful Production GM Small-Block V-8 Ever!

2013 is likely the last year for the legendary LS7 427 7-liter V-8 engine in a Z06, 427 convertible, or any new production Corvette, but it will continue on in the 2014+ Camaro Z/28 muscle-car. 2013 is also the last year for the current C6 (sixth generation) Corvette. The LS7 engine is a relatively lightweight, very powerful, not overly complex, high revving, naturally aspirated, big cubic-inch, durable, fairly economical, and compact modern muscle-car engine that's a proven winner by nearly any measure. Chevrolet or Chevy, 427, small-block, V-8 and high performance are historic keywords for the LS7 engine and the way it's perceived and marketed. Along with the LS7 we'll look at the LS7 based LSX engine and a few ideas related to Chevy muscle-cars engines.

Picture of a Lightweight aluminum GM Chevrolet LS7 427 7-liter engine block
Chevrolet LS7 427 7-liter aluminum bare block by GM
Note similarity to LSX block ->
Picture photograph of an Iron General Motors Chevrolet Performance Parts LSX heavy duty LS7 derived block
Chevrolet LSX  iron block - multiple volume options
<- Note similarity to LS7 block

General Motors Chevrolet LS7 427 Introduction: One of the greatest naturally aspirated V-8 production sports car engines of all time, the General Motors Chevrolet LS7 427 (7-liter) V8 was made famous by the C6 Z06 Corvette starting with the 2006 model year. The C6 or sixth generation Corvette began in 2005, but the LS7 427.6 (7-liter) started with the 2006 model year which became available in late 2005. It is Chevrolet's largest small-block ever. It's also Chevrolets most powerful production small-block! As mentioned earlier, the LS7 427 will move from the Corvette Z06 to the Camaro Z/28 beginning with the 2014 model year.

The 2014 Z/28 Camaro is designed as a street-legal track type muscle-car. The 2014 Z/28 Camaro LS7 engine gets the dry-sump oiling system like the Z06 and all power numbers remain about the same and the aftermarket is full of go-fast parts for the LS7 engine as it will be nearing 10 years of production and racing by the time it reaches the Z/28. The Camaro Z/28 is also lightened and tuned to pull 1.05-g in the cornering department. The Z/28 is one wicked Camaro.

The vehicle production life of the LS7 was relatively short (2006-2013), but the LS7, and engines based on the LS7, like the LSX small-block will continue to be manufactured and available as a crate (aftermarket) engines for decades to come. The LS7 crate engines even include the race track inspired dry sump oil pan, but you will need to supply the external oil tank if your application is other than a direct replacement. Also, if you're not replacing a C6 Z06, or 2013 427 Convertible Corvette engine, "Chevrolet Performance" has a complete controller kit for the LS7 crate 427 engine that includes a wiring harness, O2 sensors, a mass air flow sensor, electronic throttle controller, and the E-67 electronic control module (ECM) for easy installation and retrofit into a custom vehicle, and this makes it an excellent all around choice for high performance lightweight motor replacements. Similar controller kits exist for the tire shredding LSX line of LS7 based engines.

The LS7 was the mainstay power plant of the C6 Z06 Vette, but it was also exported for the Australian built Holden Special Vehicles 2008-09 HSV W427, and as a final farewell, the LS7 made its way into the 2013 Corvette 427 convertible. The first LS7 powered 2006 Chevrolet Z06 Corvette was capable of 198 mph, an 11.5 second quarter mile at 127 miles per hour, and could do a first gear 0-60 mph time of 3.5 seconds thanks to its high 7,000 RPM.

Picture of an LS7 7 liter 427 cubic inch Z06 engine mechanical drawing
Mechanical line drawing of the GM Chevrolet LS7 Z06 Corvette engine

Also, now that the Corvette will not exclusively claim the LS7 427 as its own, hopes are high that we'll see a 427 Camaro. Simple big cubic-inch engines are always better for long term high output reliability in our book, but advancing technology makes simple more complex as time goes on.

The new C7, or seventh generation, 2014 Chevrolet Corvette (378 C.I.D.) 6.2L LT1 generation 5 small-block V-8 base engine replacement will more complex, lighter, and more fuel efficient with direct injection, Active Fuel Management and continuously variable valve timing. This new (378 cu in) 6.2L LT1 gen 5 small-block V-8 engine will make the new standard model C7 2014 Corvette the most powerful base mode ever with around 450 horsepower and 450 lb.-ft. of torque (610 Nm) on tap, the quickest with a 0-60 sub 4 second time, and the most fuel efficient with better than 26 miles per gallon on the highway. Of course the LT1 is the base model Corvette engine replacement, and we wrote about it here. Also, we'll have the news right here when details become available on 2014 C7 Z06, ZR1, or what-ever they call the new Corvette with the super high performance engine options.

The king of cubes (cubic-inches that is) is the V-10 SRT Viper. Kudos to Chrysler for having the nerve to begin a new Viper production run with the pavement buckling 512 cubic-inch (8.4 liter) monster. Unfortunately for many though, the V-10 just doesn't have the same rumble that the purist V8 enthusiasts have grown to know and love over the decades long muscle-car wars. It's also light-years away from the sweet sound of an Italian V12. Most reviewers agree that the Viper sounds like total crap and that's quite annoying in a supercar contender, but we're not talking about Chrysler here so let's get back to it...

If you're looking for earth shaking naturally aspirated V-8 engine replacements for the modern muscle-cars, or any car, there's the LS7 based LSX engine. "Chevrolet Performance" (GM Performance Parts) has a video demonstrating the electrical hookups (harness / controller package) for an (LS7 based) LSX 454 for the Camaro. Redline Motorsports has been selling the new 5th generation Camaro with an LSX 454 motor replacement already installed called the HTR-454SS through dealers for years. Redline can also do an LSX454 motor replacement in your existing new model Camaro. Also, the LSX is built to withstand forced induction (superchargers and turbochargers), so the performance potential (taking durability into mind) of the LSX engine is beyond nearly anything widely available in the world today, especially if you also take affordability into mind. 

Since Chevrolet, the 427, high horsepower output, and small and big-block ideas come up so often with the LS7 427 V-8 were going to stray off course a little bit while exploring some of the legend behind this great motor and the things it's compared and related to.

Picture photograph of a GM Chevrolet Corvette Z06 and Corvette 427 convertible LS7 7-liter piston and connecting rod assembly
Chevrolet LS7 7.0-Liter V-8 piston and connecting rod assembly

Small-block: The LS7 is a 7-liter 427 cubic-inch V-8. The LS7 is also considered a small-block because it evolved from the previous Chevrolet small-block engine designs. As of 2011 GM had built over 100 million small-block engines. When historically talking about engines, old school thinking brings about thoughts of small blocks (mouse-motors) and big blocks (rat motors), which is generally slang or jargon terms that came about when describing Chevrolet engines beginning around 1955 (small-block) to 1958 (big-block). Simply put, the big-block is bigger in physical size  (dimension and weight). The differences are less clear with other manufacturers and most agree big and small-blocks are a Chevrolet thing because Chevrolet  has 2 different and dimensionally distinct V8 engine designs, a physically larger one, and a smaller one. As far a cubic-inches go, there are small-block engines with more cubic-inches than a big-block, but the big-block usually has more. Also, in the 1950's to 1970's the smallest displacement Chevy big-block (348 cubic-inches in cars) was larger than the smallest displacement small-block (262 cubic-inch) passenger car engine. Also, big-blocks generally, or more easily, put out higher torque numbers because of their physical characteristics. This was, and often still is, important for heavier cars and trucks among other vehicles. There was also a General Motors 400 CID policy in those days that twists itself up into this debate, but that's another story. The big-block / small-block idea later became an even more publicized and argued about concept with the muscle-car wars of the late 1960's early 1970's when high performance "big-blocks" and "small blocks" started to appear in the mid-size cars. Read a copy of the General Motors Small-Block Performance Milestones official press release for more on the small block history.

Classic big-block 427 engine: The 427 brings back thoughts of the historic 427 big-block muscle-car V-8 engines of the late 1960's and their awesome power and torque. Today's sports car motors are made to be as lightweight and compact as possible, so as far as modern vehicles go, big-blocks don't really play a role and are generally set aside for trucks and boats, though the old style big-blocks Chevy's are still big business as crate motor replacements for hot rods and classic muscle-car restorations as well as for truck and boat projects. Some of the most memorable and expensive high performance old muscle-car era 427 big-blocks had both the head and blocks made out of aluminum (ZL1) in an effort to be as lightweight as possible, while another saved some money by only using the aluminum heads on an iron block (L88), and then there was the iron block and iron head high output 427's like the L72 and tri-power L71 . The basic old 427 big block remained a production engine into the mid-1990's, but in its later years was a truck only motor. Aftermarket big block 427 crate engines are still manufactured today in a multitude of configurations. The new small block LS7 427 is actually a 428 (427.8 cu in), but 427 is legend.

Picture photograph of a Short block Anniversary 427 big block crate engine. The short block engines come without heads
Chevy "Short block" example: 
Anniversary 427 V-8 big-block crate engine
Picture photograph of a General Motors ZZ502-502 Base Big Block Crate Engine long block
Chevy "Long block" example: 
ZZ502-502 big-block V-8 crate engine

Long block vs. short block: While we're on some of the old muscle-car ideas, another thing people often think about while in this conversation is the long-blocks and short-blocks. A long-block and short-block have nothing to do with how long, or what the length of the engine is. Maybe if they had been named short blocks and tall blocks it would make better sense. Anyhow, the short-block is the bottom end of a built up engine without the cylinder heads, but NOT just the bare block with no internal parts. People usually use short-blocks when they have the cylinder heads already. A long-block is a short-block with the cylinder heads also installed on the engine. Then there are the "turn-key" long blocks that include the carburetors or fuel injection, intake manifolds, water pumps, and other externals already installed like the LS7 pictured below.

LS7: Besides 427, five hundred is another magical number that was a requirement of the initial LS7 design, 500 horsepower that is, actually 505-horsepower (377 kW) and 470 lb-ft (637 Nm) of torque. When you make over 500 horsepower in an 11.0:1 compression ratio lightweight aluminum engine and then put it into the Corvette Z06 lightweight aluminum frame you have the basics for a winning design, and the Z06 is an all around high performance sports car that is tough to beat on the road or track. In fact the LS7 427 7-liter engine is also an excellent choice for many wishing to modernize older vehicles, in car kits, and for other custom automotive applications.

Picture photograph of the passenger side front of the General Motors Chevrolet LS7 427 7L crate engine
General Motors (GM) Chevrolet LS7 427 (7 liter) crate engine

The LS7's roots are based in Motorsports design. When you have a high rev motor (7,000 rpm redline) that can win races without falling to pieces under extreme use, you have the proven basic elements needed to produce a superior power plant for the masses, though even so, each engine is assembled by hand by a single highly trained General Motors engine builder.

Technology has come a long ways when compared to the high output pre-1970's designs that over the following decades were morphed into more fuel efficient engines with a less than desirable power output for the sports car market. During these times the industry developed the technology that would be needed to satisfy the governmentally mandated, and manufacturers self imposed rules and regulations that demanded engines and vehicles make strong attempts to be as economically and environmentally friendly as possible.

The highest performing sports cars are always going to be on the edge of breaking these rules because down deep nearly all high performance enthusiasts are outlaws at heart. On the other end of the spectrum are the most fantastically economical and green automobiles the world has ever seen, along with everything in between which usually consists of the most affordable and realistic motorcars for the masses. The different types of automobiles complement each other in their designs. The ultra high performance vehicles pass on their power engineering tricks to the others, while the most economical ones pass on their thriftiness techniques throughout the line, and so on.

The rise back to pre-1970's power output has now been consistently exceeded using various spin offs of the decades old engine designs with modern features and materials added. The LS7 has its roots based in the (gen 3) Generation III LS1 engines which were used in many 1997-2004 Corvettes. These (gen 3) Generation III LS1 engines were generally rated at between 345 and 350 horsepower for the Corvette, and at slightly lower horsepower ratings for the 1998-2002 Camaro's and Trans Am's.

Measuring horsepower (the older "SAE gross power" vs. the new "SAE net power" ratings): SAE = Society of Automotive Engineers. Horsepower is not commonly measured the same way as it was in the old muscle-car days prior to the early 1970's in the United States, and it is not generally comparable to equate, say a 1969 Camaro's horsepower rating to today's engine output ratings. The older car would have quite a bit less horsepower than it was attributed with if measured by the more modern "SAE net" standards, and a new engine would have more horsepower if measured by the older "SAE gross" standards. Things were getting out of hand with the old "SAE gross" (brake horsepower - bhp) standards as many manufacturers were disconnecting all the belt driven accessories and often fitting long tube "test headers" on for the measurements instead of the power robbing manifolds the buyers would have on their new cars of the day. Both the old SAE gross and the new SAE net are measured from the crankshaft which doesn't take into account any power losses through the transmission and rear end, but the new SAE net rules demand that the standard production-type belt-driven accessories such as the air cleaner, emission controls, exhaust system, and other power-consuming accessories will NOT be stripped off, disconnected, or modified for the horsepower test measurements, thus, the horsepower rating is more in line with what a vehicle purchased by a consumer could reasonably expect out of their automobile. Lastly, as of 2005 there is a new closely supervised additional and optional "SAE certified power" rating many auto manufacturers are migrating towards including in their specs. It can be used in addition to an SAE gross or SAE net power rating to state those ratings are SAE certified.

There was also the common "horsepower was underrated by the manufacturer" statement with the old muscle-cars, but the difference between the old SAE gross and the new SAE net pretty much cancel that out. Also, the "underrated horsepower" statement was usually applied to the horsepower an engine tuner got out of the engine after he retuned or otherwise modified it which is not a fair statement of horsepower. Today we can also take a tuning software along with a few other small mods to easily turn a 500 horsepower engine into a 750 horsepower and beyond engine but this also would not be a fair measure, and greatly affects intended reliability.

Picture photograph of a real Chevrolet LS7 427 7-liter engine engine, piston, rods, crankshaft, block cutaway
LS7 427 side view aluminum engine block cutaway w/ crank, rods and pistons

GM Chevrolet LS7 427 Motor metallurgy:

Titanium: Now as far as the advance materials used the the LS7, let's take a look at titanium. Only a few years ago titanium was considered an exotic metal that was too expensive for most applications. The jet aircraft industry was one of the first transportation industries to make wide use of the material. The main qualities of titanium are its strength, corrosion resistance, its readiness to bend and shape, and its light weight. Today, with modern techniques titanium has become less costly, consistently stronger, and easier to work with, and the LS7 uses it in abundance. The most significant titanium parts in the LS7 engine are ultra-light weight connecting rods and 2.200" titanium intake valves (the exhaust valves are 1.610" sodium-filled).

Aluminum: The block and CNC-ported heads with 70cc chambers produce an 11:0 static compression ratio and are all aluminum on the LS7 (7.0 L; 427.8 cu in) engine. About CNC porting: "Computer Numerical Control" machine tools offer improved automation and flexibility with the unbelievable ability to duplicate needle point accuracy time and time again. The flat-top pistons and engine block are are also made of cast aluminum. Numerous other lightweight components throughout the vehicle are produced from aluminum.

Magnesium: The Z06 Vette also uses a magnesium engine cradle for the LS7 engine. Magnesium is the third most commonly used structural metal after iron and aluminum. Interesting note: In 1957, a Chevrolet Corvette SS concept car, designed for racing, was constructed with magnesium body panels (source: Wikipedia).

Iron: The LSX engine block is made of iron and based on the LS7 block. View obvious similarities in the photographs posted above

Forged Steel: The LS7 engine crankshaft is a forged steel design with a 101.6-mm (4-inch) stroke. Also, the LSX has an all-forged rotating assembly.

High performance plastics and polymers and carbon fiber are used extensively throughout the high performance Corvette range. Carbon fiber is generally saved for the Z06, 427 convertible, ZR1, and C6.R.

Picture photograph of the General Motors LS7 427 7-liter crankshaft
GM Chevy Corvette LS7 7L 427 forged steel crankshaft

Race proven design: The Chevrolet LS7 engine was born to race and has its roots based in the Corvette C5R race cars. Also, the Katech engineering performance tuning team had a big hand in the development of the LS7 because the Corvette C5.R racers were using a Katech modified Chevrolet LS1 engine punched out to 427 cubic-inches. The Katech specs on the enlarged LS1 where nearly perfect as a basis for the LS7 engine design which also became the LS7.R in the, then new, C6.R Corvette racers. By the way, Katech is still going strong and can hop up your GM Chevy V-8's to nearly any level you desire and they have many packages available to the public to do just that. Also, the famous Corvette Motorsports racers and makers of the C6RS custom Corvette, Pratt & Miller, have a very strong bond with Katech modified Corvette engines. Katech is still highly involved with the ongoing racing and high performance aftermarket evolution of Corvettes and Corvette engines.

Picture photograph of a LS7.R Chevrolet Corvette C6.R racing engine
LS7.R Chevrolet Corvette C6.R V-8 racing engine picture

Chevrolet LS7.R engine: The LS7.R is a race version LS7 used in the C6.R American Le Mans Series racing Corvettes. Everyone also likes to remember that the Corvette LS7.R was recognized as Global Motorsport Engine of the Year at the Professional Motorsport World Expo in Cologne, Germany in 2006 by a jury of 50 race engine engineers. Another winner of this award was the Audi V-10 TDI. Of course the specifics of the LS7.R engine build are kept secret and well hidden from prying eyes underneath the carbon fiber upper parts while the Corvette LS7.R race cars are still in competition. Also remember the ALMS (American Le Mans Series) places restrictions on how much power you're going to put out, and the engineering by GM, Katech and others is based around these restrictions. In the case of the Corvette C6.R LS7.R engine 2 38mm induction restrictors are the choke point that must be present on the race cars. Without these required restrictors this engine could be re-engineered for hundreds more horsepower. These intake restrictions are often equated to breathing through soda straws. If the restrictors were removed on the engine as it is, estimates are an easy 20% more horsepower.

Chevrolet LSX engine: The Chevy LS7 based LSX iron small-block V-8 is tested to pressures of up to 2,500 horsepower (1,900 kW) and is ready for the next level of performance beyond what an aluminum LS7 engine can reasonably handle. The LSX is extremely popular with drag racers and classic car buffs who want more modern, reliable, and powerful engines. The famous NHRA drag racer Warren Johnson helped promote the LSX engine for General Motors. The LSX engine is affordable and designed with more material than the LS7 in key areas like the deck and bores. The LSX supports bores up to the famous 454 and beyond. The LSX is most commonly available as an LSX 376 or LSX 454 cubic-incher and you can enlarge it from there if desired. The LSX 376 and LSX 454 come with a 2 year 50,000 mile warranty. Horsepower ratings for these LSX engines goes from 450 to 620 horsepower for the basic road going version of these engines and begins at 750+ horsepower for the naturally aspirated racing version of the LSX like the LSX454R. Add forced induction, or what have you, and with proper techniques you can more than triple the 750 race horsepower on an LSX based engine. The six bolts per cylinder head clamping capability allows plenty of strength for forced induction like superchargers and/or turbochargers.

Picture photograph demonstrating how the Corvette Z06 engine is identified with its red engine covers
The LS7 427 in the Chevrolet Z06 Corvette is identified with the red engine covers

Pricing for the Chevy LS7 and LSX engine: Outside of the LS7's found in Z06 Corvettes from 2006 to 2013, the 2013 Corvette 427 convertible, and the 2008-09 HSV W427, we're looking at new crate motor prices here. Used motors as motor replacements are also available in abundance on eBay, in auto scrap yards, and advertised elsewhere.

  • As of September 2012 an LS7 427 7.0L 505 hp long-block stock crate motor can be had for about $14,000 USD new and has a retail of about $17,000 USD.
  • Then there are options for modified LS7's. An example would be the Lingenfelter built 630 hp rough idle LS7 (part # L130085306) motor replacement for about $21,500 USD.
  • A basic LSX with some kind of fuel delivery system installed is going to start out at around 8 or $9,000 USD on up to $20,000 USD or more for the 750 hp LSX454R. The simple LSX long blocks start at 5 or $6,000 USD with the assembled block and heads only.

Quick Chevrolet LS7 engine specs: LS7 427 cu in 7.0L V-8 engine specifications (view photo gallery for major parts photographs):

  • Uses: 2006 to 2013 GM Chevrolet Corvette Z06, 2013 Corvette 427 convertible, Holden Special Vehicles 2008 and 2009 HSV W427, 2014 Camaro Z/28, and probably until the end of time as a General Motors "Chevrolet Performance" aftermarket crate or replacement engines.
  • Engine type: 90-degree V-8, cam in block style
  • Power output: 505 horsepower @ 6200 rpm and 475 lb.-ft. of torque @ 4800 rpm
  • Compression ratio: the compression ratio is 11.0:1
  • Fuel: 91 octane minimum, premium fuel
  • Redline: the redline is 7000-rpm (revolutions per minute)
  • Block: cast aluminum engine block with 104.8-mm (4.125-inch) bores, pressed-in cylinder liners, 6-bolt forged steel main bearing caps
  • Exhaust manifold: hydroformed exhaust headers, custom "quad flow" collector flanges
  • Intake manifold: air intake is through a composite 3 piece friction welded manifold with a 90 mm single-bore throttle body, five grams a second fuel injectors
  • Lubrication: dry-sump oiling system with remote 8 quart reservoir
  • Crankshaft: 101.6-mm forged steel crankshaft with (4-inch) stroke
  • Connecting rods: the connecting rods are forged titanium (480 grams each)
  • Pistons: piston are cast aluminum flat-top type
  • Cylinder heads: CNC-ported high temperature resistant high flow race style aluminum cylinder heads, sodium-filled exhaust valves (size: 41 mm or 1.61 inch), titanium intake valves (size: 56 mm or 2.20 inch), 12 degree valve angles, 70-cc chamber volume
  • Rocker arms: the rocker arms are 1.8:1, they're offset on the intake only
  • Camshaft: the camshaft is a hydraulic roller type, 15 mm or .591 inch lift (intake and exhaust)

Don't forget to view the General Motors (Chevrolet) LS7 427 (7-liter) picture gallery.


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