Are NASCAR engines rebuilt after every race? All you need to know

While NASCAR V8 engines may have improved through the years, the power units don't last very long. As such, teams rebuild the engines after every race to ensure optimal performance for the next race weekend.

Teams must build a certain number of engines and use all of them throughout the season. This is why running a race team in the stock car racing league can be expensive, highlighting the need for a good sponsorship deal for funding engine builds.

Let's take a closer look about what happens to NASCAR engines after every race.

NASCAR engines are rebuilt after races

For starters, a NASCAR engine is built on a V8 configuration, which, as the name suggests, has eight cylinders arranged at 90 degrees. It also utilizes pushrods and fuel injectors as opposed to carburetors about 15 years ago.

After every race, engines are rebuilt for various reasons, one of which is to ensure performance for the following races. Teams replace or repair some defective parts that could affect the power efficiency of an engine, though officials limit which parts could be replaced.

Teams also use one engine for about two races before scrapping it. With about a 36-race schedule in a year, competitors build more than 10 power units, with some being used for only one race, depending on the team's strategy.

The V8s are built with performance parts, thus prioritizing power over reliability.

NASCAR engines tend to last about two races only - Source: Imagn

Another reason for rebuilding the engine is for inspection, as the race officials will inspect power units to ensure no teams would run with illegal specifications. This procedure is mostly done on race-winning engines.

The officials don't take it easy on violators. Earlier this year, Denny Hamlin was penalized for violating engine inspection requirements. The team disassembled the sealed engine before being inspected, which docked the driver 75 points and 10 playoff points.

During the rebuilding process, teams can also take the chance to analyze the parts for data to make adjustments in future builds.

Who builds the NASCAR engines?

NASCAR has four main engine builders, namely, ECR Engines (Earnhardt-Childress Racing Technologies), Hendrick Motorsports, Roush-Yates Engines, and Toyota Racing Development (TRD).

ECR Engines and Hendrick Motorsports are responsible for engines for Chevrolet-affiliated teams, including Richard Childress Racing and HMS itself.

Chevrolet is the most successful manufacturer in NASCAR - Source: Imagn

Meanwhile, Roush-Yates Engines builds the V8 for Ford-affiliated teams including the defending champion, Team Penske. Roger Penske's race team is the champ for three consecutive seasons, with Joey Logano bringing home the latest title.

As for TRD, the Japan-based manufacturer runs with teams like Joe Gibbs Racing and Legacy Motor Club. However, LMC doesn't have a technical alliance with the top Toyota team, JGR, because the team wishes to succeed on its own.

Reports say that NASCAR president Steve Phelps is close to adding a fourth OEM.