Audi R8 42 Bare Engine BYH 4.2 FSI V8 Quattro 420HP with 79 000 miles, WARRANTY

Warranty and technical condition of the part

The engine is sold with a 90-day warranty.

The power unit was tested before removal and is in full working order.

Listing details

The offer applies to a bare engine.

The engine is sold without accessories (e.g. alternator, starter motor, manifolds, injectors, turbocharger, etc.).

Audi R8 42 Bare Engine Block BYH 4.2 FSI V8 Quattro 420HP is a proposition for demanding users looking for a solid base for professional repair or a performance project in an Audi R8. The bare block from the BYH unit forms the foundation for building a powerful, high-revving V8 gasoline engine with FSI injection and quattro drive.

Specifications and technical data

• SKU: 079100031J
• Mark: Audi
• Condition: Used
• OEM Part Number: 079100031J
• Substitutable numbers: 079100031J, 079 100 031 J, 079100031JX, 079 100 031 JX
• Fuel type: Petrol
• Number of cylinders: 8
• Part type: Engine Long Block
• Category: Engines
• Engine code: BYH
• Mileage: 79 000

Technical Characteristics of the BYH 4.2 FSI V8 Engine

The presented engine block comes from the V8 FSI gasoline engine series used in the first generation Audi R8. The BYH construction is a naturally aspirated unit with a sporty character, designed for stable operation at high RPMs and precise power delivery to all wheels in the quattro system.

As a bare engine block, the component forms a base including key block and crankshaft assembly components, intended for further completion with accessories matching the BYH code. This type of configuration is particularly beneficial for major repairs, swaps, or rebuilding the unit after accessory damage.

Application and Selection for Audi R8

The BYH 4.2 FSI V8 engine is dedicated to Audi R8 models with quattro drive, where stable transfer of high power and resistance to intensive use are crucial. When selecting an engine block, matching the engine code and verifying compatibility by OEM number or vehicle VIN is essential, minimizing the risk of installation issues.

For users who want to deepen their knowledge about the cost-effectiveness of installing used powertrains, VIN-based selection procedures, and real cost differences, we recommend the expert guide: Why Buy Used Gearboxes and Engines – Facts Instead of Myths. This is a practical supplement to information before making an engine replacement decision.

Benefits of Choosing a Used BYH Engine Block

Choosing a used BYH engine block for an Audi R8 is a solution that combines technical requirements with cost control. The main advantages of such a configuration include:

• Savings compared to a complete unit – you pay for the engine base, and you can transfer the accessories from the existing unit or select them according to your project's specifications.
• Possibility of individual configuration – a bare block is a good starting point for modifications, a general overhaul, or building an engine for a specific track or street specification.
• Better control over the repair process – the mechanic has complete freedom in selecting cooperating components, which facilitates maintaining consistency with Audi's factory specifications or a tuning project.
• Rational use of original components – functional accessories from the existing engine can be reused, which reduces costs without sacrificing OEM quality.

Condition, Mileage, and Suitability for Further Work

The unit is offered as a used engine block, which means that before installation, a standard verification procedure in a specialized service is recommended (compression measurement after assembly, clearance check, assessment of cylinder bore and crankshaft assembly condition). The declared mileage allows this engine to be treated as a good base for a partial or full overhaul, depending on the user's assumptions.

For Audi owners planning broader modernization or repair work using aftermarket components, a valuable addition to knowledge will be the article: Audi with Second-Hand Parts – Tuning and Repairs Without Losing Quality. It allows for better planning of the scope of work and selecting components in terms of durability and the car's character.

Other Audi Engines – Expanding Your Project

If you are planning a larger project related to powertrains of this brand and are also interested in other Audi engines for various models, check the available items in the Audi engines category. This is a convenient way to compare different engine codes, configurations, and bases for various applications – from series repairs to ambitious tuning projects.