Wiseco K553M845 Forged Piston Kit for 1994-2005 Mazda Miata / Protege 1.8L

Vehicle Fitment

• 1994-2005 Mazda MX-5 / Miata (1.8 L BP-ZE / BP, 16V)
• 1999-2000 Mazda Protege / 323 (1.8 L BP-ZE / BP, 16V)

Features

• Forged from 2618 aerospace-grade aluminum for high strength
• ArmorGlide® skirt coating to reduce friction and improve durability
• Dished crown (-4.0 cc) to lower compression and increase tuning flexibility
• Strutted forging design for added rigidity under load
• Precision ring grooves with anti-detonation groove
• Forced pin oiling to maintain wrist-pin lubrication
• Premium 8450XX high-performance ring set included
• Built for high-RPM, track, or tuned naturally aspirated builds

Specifications

• Bore: 84.50 mm
• Compression Height: 30.50 mm
• Piston Dish Volume: -4.00 cc
• Compression Ratio: ~8.5:1 
• Wrist Pin Diameter: 20 mm 
• Set Quantity: 4 pistons
• Ring Set: 8450XX series 
• Piston Weight: ~315 g 

Included Components

• 4x forged pistons
• 4x 20 mm wrist pins
• 4x 8450XX piston ring sets
• 4x circlips / locking rings

Product Description

The Wiseco K553M845 piston kit is engineered for Mazda's 1.8 L BP-engine (16-valve) platforms, including Miata (1994-2005) and Protege / 323 (1999-2000). Crafted from 2618 forged aluminum, these pistons offer superior strength for high-RPM and performance-focused applications.

With a -4.0 cc dish, the compression ratio is tuned to approximately 8.5:1, giving you a safer margin for detonation while preserving power potential. The ArmorGlide® skirt coating reduces friction and noise, while the strutted forging design adds structural rigidity under load. Forced-pin oiling ensures consistent lubrication of the 20 mm wrist pins for enhanced durability.

This complete kit includes pistons, wrist pins, circlips, and a top-quality 8450XX ring set, making it ideal for a full rebuild or race-spec engine. Whether you're building a high-RPM naturally aspirated engine or a tuning project, the K553M845 delivers reliable performance and strength.