Mahle 930227355 LSX Combo PowerPak Piston Kit 4.155 447ci Flat Top 11.8 CR 2618

Vehicle Fitment

• Universal - fits any GM LS-based V8 engine block bored to 4.155 in. using a 4.125 in. stroke crankshaft and 6.125 in. connecting rods (447ci displacement)
• LSX Combo valve pocket geometry fits LS1/LS2/LS6 cathedral port heads, LS7 12-degree heads, and LS3/L92 rectangular port heads
• Common platform applications: Chevrolet Camaro SS/Z28 (LS1/LS2/LS3), Corvette C5/C6 (LS1/LS2/LS3/LS7), Chevrolet Silverado/GMC Sierra (LS-based V8), GTO (LS1/LS2), Pontiac Firebird (LS1), and other LS-platform vehicles with compatible engine builds

Fitment Notes

• This is a performance piston and ring kit - not a direct OE replacement; requires block to be bored and honed to 4.155 in. before installation
• LSX Combo flat top does NOT fit 5.3L LS truck heads (706 or 862 castings) - use a 5.3L-specific piston for those applications
• Requires a 4.125 in. stroke crankshaft and 6.125 in. connecting rods to achieve the 447ci stroker displacement
• Compression ratio of 11.8:1 calculated at zero deck with 0.040" head gasket and 72cc combustion chamber - verify CR with your specific head, gasket, and deck clearance
• Rings are file-fit - ring end gaps must be confirmed and set to spec before installation
• Sold as a complete set of 8 pistons with rings, pins, and wire locks included
• Not legal for sale or use in California or CARB-regulated states

Features

• Forged 2618 aluminum alloy for maximum detonation resistance and high-temperature strength - ideal for supercharged, turbocharged, nitrous, and high-compression naturally aspirated builds
• LSX Combo universal valve pocket geometry - single piston design fits LS1/2/6 cathedral port, LS7 12-degree, and LS3/L92 rectangular port cylinder heads without modification
• HV385 coated steel 1.0mm top ring and Napier 1.0mm second ring for superior combustion sealing and oil control
• Hard anodized top ring groove prevents micro-welding and ring land wear under extreme cylinder pressures
• Grafal anti-friction skirt coating reduces drag, scuffing, and cylinder bore wear for long-term durability
• Phosphate dry lubricant on pin bores and ring grooves protects against galling during initial startup and break-in
• Slipper skirt forging design reduces reciprocating mass for improved high-RPM throttle response
• Top ring land set down 0.250 in. with 0.200 in. second land thickness for added ring groove durability under boost and power-adder loads

Specifications

• Engine Family: GM LS V8 - LSX Large Bore Stroker (447ci)
• Bore: 4.155 in.
• Stroke: 4.125 in. (requires stroker crankshaft)
• Rod Length: 6.125 in.
• Compression Height: 1.050 in.
• Pin Diameter: 0.927 in.
• Crown Volume: -5.8 cc (Flat Top)
• Piston Weight: 450 g (each)
• Alloy: 2618 Forged Aluminum
• Compression Ratio: 11.8:1 (at zero deck, 0.040" gasket, 72cc chamber)
• Ring Pack: 1.0mm HV385 / 1.0mm Napier / 2.0mm - File-Fit
• Top Ring Groove: Hard Anodized
• Compatible Heads: LS1/LS2/LS6 (cathedral), LS7 (12-degree), LS3/L92 (rectangular)
• Quantity: Set of 8

Included Components

• 8x Forged 2618 Aluminum Pistons (flat top, -5.8cc, Grafal + phosphate coated, hard anodized top ring groove)
• 8x Wrist Pins (0.927 in. diameter)
• 16x Wire Locks / Oil Rail Supports (pin retention)
• 8x Top Compression Rings (1.0mm, HV385 coated steel, file-fit)
• 8x Second Compression Rings (1.0mm, Napier, file-fit)
• 8x Oil Ring Assemblies (2.0mm, 3-piece)

Product Description

The Mahle Motorsport 930227355 is a complete LSX Combo PowerPak forged piston and ring kit for GM LS V8 engine builds displacing 447ci at 4.155" bore and 4.125" stroke. Built from 2618 forged aluminum alloy with a hard anodized top ring groove, this kit is engineered for high-output power-adder and naturally aspirated LS builds where detonation resistance, ring land durability, and head compatibility flexibility are critical. The LSX Combo flat top crown features universal valve pockets that fit LS1/2/6 cathedral port heads, LS7 12-degree heads, and LS3/L92 rectangular port heads - making this one piston set the correct choice for a wide range of LS cylinder head combinations without requiring separate piston designs for each head style.

The included 1.0/1.0/2.0mm file-fit ring set features an HV385 coated steel top ring and Napier second ring for superior combustion sealing and oil control, with low reciprocating mass for improved response at high RPM. The top ring land is positioned 0.250" down with a 0.200" second land thickness for added durability under boost and nitrous loads. The cylinder block must be bored and honed to 4.155" and a 4.125" stroke crankshaft with 6.125" connecting rods are required to achieve the 447ci displacement. Ring end gaps must be confirmed and set to spec before installation. This piston does not fit GM 5.3L LS truck heads with 706 or 862 castings.