How much hp does a 429 Cobra Jet have?
Approximately 360–370 horsepower for the standard 429 Cobra Jet, with the higher-performance Super Cobra Jet around 375 horsepower. These are gross-era ratings and can vary by year and setup.
Overview of the 429 Cobra Jet
The 429 Cobra Jet (CJ) was Ford’s high-performance version of the 429 cubic-inch V8, introduced in 1968 for muscle cars like the Mustang and Torino. The Cobra Jet designation signified a package that included features such as higher compression, improved cam timing, and often dual exhaust, aimed at delivering stronger performance. A more extreme variant, the Super Cobra Jet (SCJ), offered even more power and was used in applications oriented toward drag racing and high-performance trim.
Variant horsepower figures
The two main variants in the 429 CJ family are the standard Cobra Jet and the Super Cobra Jet. The figures below reflect typical gross horsepower ratings from the late 1960s era.
- 429 Cobra Jet (CJ): approximately 360–370 horsepower
- 429 Super Cobra Jet (SCJ): approximately 375 horsepower
In practice, individual engines and configurations could show slight deviations depending on year, exhaust setup, carburation, and emission controls.
Rating method and historical context
Horsepower ratings in the late 1960s were usually gross horsepower, measured with minimal accessories and often with more open exhaust. Modern comparisons use net horsepower numbers, which account for standard equipment and accessories and are typically lower. Because of this, CJ/SCJ figures from the era don’t map directly to contemporary ratings and can vary by testing method and model year.
Where these engines appeared
In Ford’s lineup, the 429 CJ and its SCJ variant were used in high-performance versions of the Mustang and Torino, among others. The CJ package was aimed at enthusiasts seeking strong straight-line speed, while the SCJ tier pushed the performance envelope further for drag-focused applications.
Notes on historical accuracy
For those researching classic Ford muscle, period Ford brochures, dealer catalogs, and contemporary automotive press provide the most reliable figures. Variations exist due to year-specific tuning, emissions equipment, and whether the engine was equipped with certain performance options at the factory.
Summary
The 429 Cobra Jet delivered about 360–370 hp in its standard form, with the Super Cobra Jet offering around 375 hp. These numbers reflect the gross horsepower ratings of the era and can differ based on year, configuration, and testing method. When comparing to modern engines, keep in mind the shift from gross to net horsepower ratings and the evolution of emissions controls and drivetrain accessories.
What is the actual HP of a 428 Cobra Jet?
The 428 Cobra Jet engine was officially rated at 335 horsepower, but this was an understatement used to appease insurance companies and meet drag strip regulations. In reality, the engine's true horsepower was widely believed to be over 400 hp, with dyno tests showing figures around 365 to 375 hp in stock form, and even higher when equipped with headers.
You can watch this video to learn about the 428 Cobra Jet engine's history and performance: 59sIts Just Cars!YouTube · May 7, 2024
- Officially advertised: 335335335 hp
- Estimated real-world horsepower: Exceeding 400400400 hp
- Dyno-tested (stock): Around 365365365 hp to 375375375 hp after break-in
- With headers: Potentially over 400400400 hp
- Torque: Officially 440440440 lb-ft, with some tests showing slightly higher figures as well
What is the difference between the 429 and the 429 Cobra Jet?
The 429 Thunderjet and Cobra Jet featured similar two-bolt main bearing 385 big block architecture, although the 429 Cobra Jet block featured stronger webbing around the main bearings. The most significant differences between the two were compression ratio, cylinder head construction, and carburetors.
How much horsepower does a 1971 Ford 429 have?
370 horsepower
The 1971 Ford Mustang, particularly the 429 C-Code convertible, was a significant model in the muscle car era. The C-Code engine, a 429 cubic inch big-block V8, offered 370 horsepower. Only 42 of these 429 C-Code convertibles were produced, making them very rare and highly sought-after by collectors.
What is the true horsepower of a 429 Cobra Jet?
As mentioned, Ford reported 360 horsepower from the 429 Thunderjet with torque values at 480 lb-ft. The decidedly higher performance 429 Cobra Jet, on the other hand, was rated at 370 horsepower but lost 30 lb-ft of torque somehow with its 450 lb-ft rating.
