1S1970 Chamber A Fits Caterpillar Models

One New Aftermarket Replacement Precombustion Chamber (Chamber A) for Caterpillar (Cat) Engines

This aftermarket replacement precombustion chamber (pre-cup) fits Caterpillar D311, D315, D318, and D318G indirect-injection diesel engines. The precombustion chamber is the cavity in the cylinder head where fuel is initially ignited before combustion spreads to the main cylinder. During operation, these chambers endure extreme compression forces and heat cycles; over time they can crack or work loose, risking serious damage to the cylinder head or engine block. Replacing a worn or damaged chamber restores proper combustion efficiency and protects the surrounding assembly.

Specifications

• Diameter: 55mm
• Compatible glow plug: 3H2033 (pencil-type)
• Associated hardware: outer O-ring seal 2H3088, injector retainer nut 6F8061, O-ring seals 5B3718 (sold separately)

Compatible Engines / Models

Caterpillar Engine Applications: D311, D315, D318, D318G

Caterpillar Equipment (D6 series and others powered by the above engines): Verify your engine model number before ordering. Note: ACMOC forum sources reference a chamber size change on the D6 9U series at serial number 9U11705 -- confirm fitment for D6 9U machines near or above that serial break.

Replaces Part Number(s):

1S1970, 1S-1970

Aftermarket Interchange Numbers

2S1273, 2S-1273, 4F8517, 4F-8517

New aftermarket replacement part - not remanufactured, not used.