King Engine Bearings MB5799SI0.25 Main Bearing Set Subaru FA20 Toyota 4U-GSE 0.25mm OS Housing

The King Engine Bearings MB5799SI0.25 is a main bearing set engineered for the Subaru FA20 and Toyota 4U-GSE engines, featuring an oversize housing dimension of +0.005" (0.127mm). Designed for precision fitment in performance and OEM replacement applications, this set delivers reliable crank support under medium load conditions.

Material Construction:

• Bi-Metal Silicon Aluminum — aluminum-based bearing material strengthened with 2.5–3% silicon content
• Optimized for medium-load engines and nodular cast iron crankshafts
• Silicon aluminum alloy provides excellent conformability and embeddability to protect crankshaft journals
• Bi-metal construction offers a strong steel backing for dimensional stability and load support

Specifications:

• Application: Subaru FA20 / Toyota 4U-GSE engines
• Housing Oversize: +0.005" OS
• Material: Bi-Metal Silicon Aluminum (Si-Al)
• Silicon Content: 2.5–3%
• Part Number: MB5799SI0.25

King Engine Bearings is a globally recognized manufacturer of precision engine bearings, supplying OEM and aftermarket applications worldwide. The SI (Silicon Aluminum) series is a trusted choice for engines running nodular cast iron cranks where a balance of strength and conformability is essential.