Mercedes-AMG M157 Forged Internals — 1,500HP+ Rated | Rods & Pistons | YPG Motorsport

Mercedes-AMG M157 Forged Internals — Rods & Pistons Kit

The Mercedes-AMG M157 5.5L twin-turbo V8 is the engine found in the second-generation AMG 63 family — E63, S63, G63, CLS63, GLE63 and more. From the factory it uses a forged steel crankshaft but cast hypereutectic pistons, which become the failure point on high-output builds. The M157 is also known for cylinder scoring at higher power levels — a problem our forged internals kit addresses directly when combined with Darton sleeve inserts. Our M157 forged internals kit replaces the weak points with race-grade 4340 steel components capable of 1,500HP.

What's Included

• 8x Forged Connecting Rods — 4340 aircraft-grade steel, H-beam design
• 8x Forged Pistons — 98mm bore, replaces stock cast hypereutectic units
• ARP Main Bolts & Rod Bolts — 220,000 PSI rated
• Piston Rings — Low-tension performance ring pack
• Wrist Pins & Clips — High-strength tool steel
• Balanced and Matched Set — within ±1.5g
• Compatible with Darton Mid-Sleeve builds for ultimate reliability

Key Features

• Ceramic-Coated Piston Tops — Thermal barrier coating reduces heat transfer to the piston crown, protecting against detonation at high boost levels
• Teflon-Coated Skirts — Anti-friction coating reduces piston-to-wall contact friction, improving reliability and reducing wear under sustained high-RPM operation
• Factory Compression Ratio — Maintains stock compression geometry for seamless integration with OEM or aftermarket ECU calibrations
• 1,500HP+ Rated — Engineered to withstand extreme cylinder pressures from upgraded turbos and aggressive ignition timing
• Darton Sleeve Compatible — Designed to pair with Darton Mid-Sleeve inserts for the ultimate M157 reliability solution

Only need pistons?
If your factory M157 rods are still serviceable, we offer standalone forged piston sets at $2,499 — same 1,500HP+ spec with ceramic-coated crowns and Teflon-coated skirts. Note: for high-boost M157 builds we still recommend Darton Mid-Sleeves regardless of piston choice.
M157 Forged Pistons →

Compatible Vehicles

• Mercedes-AMG E63 (W212) — 2011–2016 and E63 S (W212) — 2013–2016
• Mercedes-AMG S63 (W222) — 2013–2017 and S63 (W221) — 2011–2013
• Mercedes-AMG CLS63 (W218) — 2011–2014 and CLS63 S (W218) — 2013–2014
• Mercedes-AMG G63 (W463) — 2012–2015
• Mercedes-AMG ML63 (W166) — 2011–2015
• Mercedes-AMG GL63 (X166) — 2012–2015
• Mercedes-AMG GLE63 (C292) — 2015–2019
• Mercedes-AMG SL63 (R231) — 2012–2016
• Engine: M157 5.5L Twin-Turbo V8 (DE55 AL)

The Cylinder Scoring Problem

The M157 has a known issue with cylinder scoring under high-boost, high-heat operation. The aluminium block wears unevenly, causing irreversible damage. Our forged internals kit paired with Darton Mid-Sleeves eliminates this permanently — the combination that every serious M157 builder runs. Contact YPG Motorsport to discuss the complete sleeve and forged build package.

Why YPG Motorsport?

YPG Motorsport holds the world record for the first sub-10-second Mercedes-AMG C63 W205 quarter mile (9.97s at 828 WHP). Our forged internals kits across the entire AMG range — M133, M156, M157, M177, M178 — are sourced from CP-Carrillo or equivalent tier-1 forging houses, inspected and matched before shipping.

Ships worldwide via FedEx International Priority from Kuwait.

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