Product Analysis: Cylinder Liner 32607‑03400 & 32507‑62400 for Mitsubishi S6A2‑PTA / S12A2‑PTAA Diesel Engines

This article covers two critical cylinder liner part numbers designed for Mitsubishi’s S6A2‑PTA (6‑cylinder inline) and S12A2‑PTAA (12‑cylinder V‑configuration) diesel engines. Both liners share the same bore diameter but differ in overall length and sealing groove configuration.

1. Basic Specifications & Parameters

Cylinder Liner 32507‑62400 (for S6A2‑PTA)

This liner is the same as covered previously for S6A series, but here we focus on its application in the S6A2‑PTA engine – a turbocharged and aftercooled generator/marine engine.

• Part Number: 32507‑62400

• Liner Type: Wet liner

• Material: Centrifugal cast alloy iron (boron alloyed, high chrome)

• Hardness: HB 220–260

• Surface Finish: Plateau honed, Ra 0.25–0.45 μm

• Bore Diameter: 135.00 mm

• Flange Diameter (top) : 155.0 mm

• Overall Length: 345 mm

• Lower Outer Diameter: 142.0 mm

• O‑ring grooves: 2 lower + 1 upper

• Coolant side coating: Anti‑cavitation (tin or wax based)

• Weight: 14.5 kg

Cylinder Liner 32607‑03400 (for S12A2‑PTAA)

The 32607‑03400 is specifically engineered for the larger S12A2‑PTAA V12 engine, which produces significantly higher power and requires a stronger, longer liner with additional sealing.

• Part Number: 32607‑03400

• Liner Type: Wet liner (heavy duty)

• Material: High‑nickel / chromium alloy centrifugal cast iron (improved high‑temperature strength)

• Hardness: HB 230–270

• Surface Finish: Plateau honed, Ra 0.30–0.50 μm

• Bore Diameter: 135.00 mm (same as S6A2)

• Flange Diameter (top) : 158.0 mm (larger flange to suit V12 block)

• Overall Length: 370 mm (longer to accommodate deeper V12 crankcase)

• Lower Outer Diameter: 145.0 mm

• O‑ring grooves: 3 lower + 1 upper (extra groove for higher cylinder pressure)

• Coolant side coating: Anti‑cavitation & anti‑pitting (epoxy enhanced)

• Weight: 17.8 kg

Both liners are 100% inspected for roundness (≤0.025 mm), taper (≤0.03 mm), and hydrostatic pressure tested (8 bar for 32507‑62400, 9 bar for 32607‑03400).

2. Compatible Engines & Applications

Engine: Mitsubishi S6A2‑PTA

• Configuration: 6‑cylinder, inline, turbocharged, aftercooled

• Power range: 250–400 kW (generator set) / 350–550 HP (marine)

• Typical uses:

• Standby/prime generators for telecom, hospitals, data centers

• Marine propulsion for small workboats and fishing vessels

• Industrial pumps and compressors

Engine: Mitsubishi S12A2‑PTAA

• Configuration: 12‑cylinder, 60° V‑angle, turbocharged, aftercooled (PTAA = Pressure Turbocharged Aftercooled)

• Power range: 600–1000 kW (generator) / 800–1350 HP (marine)

• Typical uses:

• Large generator sets (prime power for mining, oil & gas)

• Marine main engines for tugboats, ferries, and coastal freighters

• Heavy industrial drives (crushers, mills)

Important compatibility note:

• 32507‑62400 fits S6A2‑PTA only (also S6A, S6A2, S6A3 naturally aspirated or turbo).

• 32607‑03400 fits S12A2‑PTAA only. Do not attempt to cross‑fit – the liner length, flange diameter, and O‑ring layout are different.

• Always check the original part number stamped on the old liner before ordering.

3. Performance Advantages & Functional Improvements

Using high‑quality aftermarket liners from Rsolid Engine Parts provides the following benefits for both S6A2‑PTA and S12A2‑PTAA engines:

• Extended Service Life – The boron/nickel/chromium alloy composition delivers outstanding resistance to ring groove wear and scuffing. Field data shows 12,000–15,000 hours for S6A2‑PTA and 10,000–12,000 hours for the higher‑loaded S12A2‑PTAA – 20‑30% longer than basic cast iron liners.

• Superior Heat Transfer – Wet liner design with optimized outer surface texture reduces cylinder wall temperature by 15–20°C. Cooler operation prevents oil coking, reduces ring sticking, and extends head gasket life – critical in continuous‑load generator applications.

• Reduced Oil Consumption & Blow‑by – The plateau honed finish (Ra ≤0.50 μm) with a precise cross‑hatch angle (30–45°) ensures rapid ring seating and excellent oil film retention. Users report 20‑25% lower oil consumption compared to reconditioned or low‑quality liners.

• Anti‑Cavitation Protection – The factory‑applied coating prevents pitting on the coolant side, a common failure in constant‑speed generator sets and marine engines. This avoids coolant leaks, overheating, and premature liner replacement.

• Precision Fitment – Each liner is machined to OEM tolerances (roundness ≤0.025 mm, taper ≤0.03 mm). This eliminates piston slap, reduces engine noise, and improves fuel efficiency by 3‑5%.

• Drop‑in Installation – Exact dimensional match. No post‑machining required. The 32607‑03400 liner includes three lower O‑ring grooves (instead of two) to handle higher cylinder pressures in the S12A2‑PTAA engine.

• Higher Strength for Turbocharged Aftercooled Engines – Tensile strength ≥320 MPa (32507‑62400) and ≥350 MPa (32607‑03400) ensures reliability under peak cylinder pressures up to 180 bar (S12A2‑PTAA).

Installation tips for both liners:

• Always use new O‑rings (specifically for each part number).

• Measure liner protrusion above block deck: S6A2‑PTA: 0.05–0.10 mm; S12A2‑PTAA: 0.07–0.12 mm. Adjust with shims.

• Replace piston rings, cylinder head gasket, and rod bearings when doing a full overhaul.

4. Why Choose Rsolid Engine Parts for These Cylinder Liners?

Rsolid Engine Parts (www.rinjector.com) is your trusted source for Mitsubishi diesel engine components. Here’s why customers choose us for 32507‑62400 and 32607‑03400 cylinder liners:

• OEM‑Grade Quality – Manufactured by ISO 9001:2015 certified foundries using original Mitsubishi specifications. No shortcuts.

• Rigorous Quality Control – Every liner undergoes:

• Hardness test (3 points)

• Air gauge measurement (roundness, taper)

• Liquid penetrant inspection

• Anti‑cavitation coating thickness check

• Hydrostatic pressure test (8–9 bar)

• Competitive Pricing – Direct factory sourcing allows us to offer 30–45% savings compared to genuine Mitsubishi parts.

• Fast Global Shipping – Stock available for single liners or full sets (6 liners for S6A2‑PTA, 12 liners for S12A2‑PTAA). Express delivery via DHL/FedEx (3–7 days worldwide).

• Technical Support – Our experts assist with compatibility checks, installation advice, and troubleshooting. Contact us 24/7 via WhatsApp: +8615975376778.

• Warranty – 12‑month unlimited‑hour warranty against material and manufacturing defects.

Browse our complete catalog at www.rinjector.com or reach out via WhatsApp: +8615975376778 for quotes, bulk orders, or technical documentation.