What size engine does Chevy use in NASCAR?

Chevrolet’s NASCAR Cup Series cars run a 358-cubic-inch (about 5.86-liter) naturally aspirated V8 built to NASCAR’s rulebook. In practice, that’s the Chevrolet R07 pushrod V8 architecture used by Chevy teams, tuned to series-mandated power levels and RPM limits. Below, we explain how this engine fits within NASCAR’s regulations, how power is managed at different tracks, and how Chevy-powered entries differ across NASCAR’s top series.

The Cup Series standard: Chevrolet’s 358-cubic-inch R07 V8

In the NASCAR Cup Series, Chevrolet teams use an engine based on the Chevrolet R07 architecture, a purpose-built racing V8 that conforms to NASCAR’s long-standing maximum displacement of 358 cubic inches. It’s a 90-degree, two-valves-per-cylinder, pushrod design, naturally aspirated and running electronic fuel injection. Since the Next Gen era began in 2022, NASCAR has paired this architecture with a spec ECU and a 9,000 RPM limit, keeping performance within tight parity across manufacturers.

Key hardware characteristics

The R07 is an evolution of Chevrolet’s small-block racing lineage, engineered specifically for sustained high-load oval racing. Bore and stroke are set within NASCAR rules to meet the 358 cu in cap—teams typically work near a roughly 4.18-inch bore with an approximately 3.25-inch stroke, though exact values can vary within the rulebook to optimize power and durability under the mandated RPM ceiling.

Power, RPM, and fueling rules

While displacement is fixed, NASCAR controls performance through RPM, air, and aero rules. The Cup engine’s revs are capped at 9,000 RPM. Power targets are package-dependent: approximately 670 horsepower at most tracks, and about 510 horsepower at Daytona, Talladega, and Atlanta using tapered spacers to reduce airflow. All cars run Sunoco Green E15 fuel, and engine mapping is controlled via the spec ECU to ensure regulatory compliance.

The following list summarizes the core specifications fans most often ask about regarding Chevy’s NASCAR Cup engine setup.

• Displacement: 358 cubic inches (approx. 5.86 liters)
• Configuration: 90-degree pushrod V8, two valves per cylinder, naturally aspirated
• Architecture: Chevrolet R07 (common across Chevy Cup teams via the Hendrick Motorsports–ECR Engines technical alliance)
• Fueling and electronics: Electronic fuel injection with a NASCAR-spec ECU
• RPM limit: 9,000 RPM (Cup Series)
• Power: Around 670 hp at most tracks; about 510 hp at superspeedways (rules package dependent)
• Fuel: Sunoco Green E15
• Bore/stroke: Typically near a ~4.18-inch bore and ~3.25-inch stroke to meet the 358 cu in cap

Taken together, these elements define how Chevrolet’s Cup engines achieve both durability and parity under NASCAR’s tightly controlled technical framework.

How Chevy power differs across NASCAR’s top series

NASCAR’s engine rules vary by series, so “what Chevy runs” depends on where you look. The Cup Series uses the R07-based 358 cu in V8, while other series employ different approaches to align cost, reliability, and parity with their respective competition formats.

Cup Series

Chevy teams run the 358 cu in R07 pushrod V8 with EFI, governed by a 9,000 RPM limit and track-specific power packages (roughly 670 hp standard; about 510 hp on the biggest superspeedways). Development and production are handled through a collaborative program between Hendrick Motorsports and ECR Engines for Chevrolet’s roster of teams.

Xfinity Series

Chevrolet entries in Xfinity also use pushrod V8s built to a 358 cu in limit. Teams may run “open” (team-built) engines or the series-approved spec alternative, depending on program choice and budget. Power levels and components differ from Cup, but the displacement standard is similar.

Craftsman Truck Series

Even Chevrolet-badged trucks in the Craftsman Truck Series typically use the Ilmor NT1 spec engine, a sealed 6.0-liter (about 366 cu in) pushrod V8 designed for cost control and parity. While the body and branding are Chevrolet Silverado, the engine package is the series’ common spec rather than a Chevrolet-built R07.

Why 358 cubic inches?

NASCAR adopted the 358 cu in displacement cap decades ago to rein in speeds, improve safety, and contain costs while maintaining the character of American pushrod V8 racing. That cap—combined with modern controls like tapered spacers, EFI, a spec ECU, and RPM limits—lets manufacturers compete closely on track without runaway performance or budgets.

Summary

Chevy’s NASCAR Cup Series engine is a 358-cubic-inch (5.86-liter) naturally aspirated pushrod V8 based on the Chevrolet R07 architecture, operating under a 9,000 RPM limit and delivering roughly 670 hp at most tracks (about 510 hp at the largest superspeedways). Xfinity Chevrolets also run 358 cu in V8s, while Chevy-branded entries in the Truck Series use the Ilmor NT1 6.0-liter spec engine. Across the board, displacement and power are shaped by NASCAR’s rules to keep competition tight and costs manageable.

Are nascars V6 or V8?

V8 engines
The cars are currently powered by EFI V8 engines, since 2012, after 62 years using carburetion as engine fuel feed with compacted graphite iron blocks and pushrod valvetrains actuating two-valves per cylinder, and are limited to a 358 cubic inch (5.9-liter) displacement.

What engine is Ford using in NASCAR?

Ford’s primary NASCAR engine is the FR9 V8, a purpose-built racing engine developed by Roush Yates Engines. The FR9 is an electronic fuel injection (EFI) engine that produces 750-800 horsepower, with designs featuring specific components for Ford teams in NASCAR’s highest series, the Cup Series. Key features include a 358 cubic-inch displacement, a high-revving nature, and a focus on reliability and high-RPM power delivery, as noted in the provided sources.
 
Key Characteristics of the FR9 Engine

• Engine Type: A purpose-built V8 engine, meaning it was designed from the ground up specifically for racing, rather than being derived from a production vehicle. 
• Displacement: The engine has a 358 cubic-inch displacement, a common standard in NASCAR. 
• Power Output: The engine produces approximately 750-800 horsepower, with variations based on restrictor plates or other rule restrictions. 
• Fuel Delivery: The modern FR9 uses an electronic fuel injection (EFI) system, a shift from earlier carbureted engines, and is controlled by a spec ECU mandated by NASCAR. 
• Design: The FR9 features a design with race-specific aluminum or iron castings and is built by Roush Yates Manufacturing Solutions in Mooresville, NC. 
• Reliability: Modern coatings and materials contribute to enhanced reliability, with some builds lasting well over 1,000 race miles. 

Evolution and Legacy

• Historical Context: The FR9’s development builds on Ford’s long history of NASCAR engine development, including earlier purpose-built engines like the C3 and D3. 
• Technology: The shift to EFI in the FR9 brought modern automotive technology to NASCAR. 
• Ford Teams: The FR9 has powered numerous Ford teams, including Team Penske and RFK Racing, to race wins and championships. 

What engine was banned from NASCAR?

NASCAR has banned several engines throughout its history, but two prominent examples are the Ford 427 SOHC Cammer due to its advanced single overhead camshaft design, and the Chrysler 426 Hemi because of its overwhelming dominance, which led to fears of uncompetitiveness. Additionally, the engine in the 1969 Chevrolet Corvette Grand Sport was also banned, not due to rule-breaking, but because GM corporate policy prohibited its factory entry into the competition.
 
The Ford 427 SOHC Cammer

• What it was: A high-performance V8 engine with single overhead camshafts (SOHC) and electronic fuel injection, designed to compete with Chrysler’s Hemi. 
• Why it was banned: NASCAR banned overhead camshaft (OHC) engines, making the Cammer ineligible for stock car competition. 
• Aftermath: Ford shifted its focus to drag racing, where the engine became a legendary and dominant force. 

This video explains why the Ford 427 SOHC Cammer was banned from NASCAR: 38sRare Car StorysYouTube · Feb 12, 2025
The Chrysler 426 Hemi 

• What it was: An incredibly powerful and compact engine that quickly achieved a high level of success in NASCAR. 
• Why it was banned: The Hemi’s dominant performance was so overwhelming that it was banned to “level the playing field” and restore unpredictability to races. 
• Aftermath: The ban wasn’t permanent, and the Hemi was allowed back into NASCAR after rules were revised to ensure its availability in production cars. 

You can watch this video to learn about the history of Hemi engines in NASCAR: 55s4 Wheels ChroniclesYouTube · Sep 23, 2023
Other Notable Banned Engines 

• Smokey Yunick’s “Mystery Motor”: This advanced Chevrolet engine was banned by NASCAR before it ever raced, though not for breaking rules but due to the potential for it to completely rewrite the sport’s history.

What engines do Chevy Nascars use?

Chevrolet’s current NASCAR engine is the R07, a 358 cubic-inch (5.8-liter) V8 with a pushrod valvetrain and two valves per cylinder, built by Hendrick Motorsports and ECR Engines. This naturally aspirated, liquid-cooled engine is a bespoke racing design, not a production engine, and can produce over 850 horsepower when unrestricted. It features a compacted-graphite-iron block and is a descendant of the iconic small-block Chevy design, with internal cooling passages and a dry-sump lubrication system.
 
Key Specifications & Features 

• Engine Type: 358 cubic-inch (5.8-liter) V8
• Valvetrain: Pushrod-actuated two-valves per cylinder
• Block Material: Compacted-graphite-iron
• Cooling System: Internally integrated coolant and oil passages
• Lubrication System: Dry-sump system that holds six gallons of oil
• Fuel Delivery: Holley EFI throttle body

Development & Purpose

• The R07 was introduced in 2007 and has been refined in collaboration with NASCAR teams like Hendrick Motorsports and Richard Childress Racing. 
• Its architecture maintains the basic small-block Chevy design, but with advanced materials, tighter tolerances, and improved surface finishes for higher performance. 
• It is a true racing engine, with internal components designed for high RPMs (around 9300-9600 RPM) and high horsepower output. 

This video shows how a NASCAR engine is built: 1mStay TunedYouTube · Mar 29, 2024
Performance

• While capable of revving to 10,000 RPM, the engine’s RPM is limited on the track. 
• In unrestricted trim, the R07 is known to produce over 850 horsepower, with continuous effort from engine builders like ECR to find even minor gains. 

You can watch this video to see a NASCAR engine swapped into a street car: 58sStay TunedYouTube · Aug 24, 2024