What compression ratio can I expect with these pistons?

With a 3.500-inch stroke and 64cc combustion chambers, you can expect around 12.5:1 compression. Using a 3.750-inch stroke with the same chamber volume raises it to approximately 13.1:1. Final compression will depend on your specific cylinder head volume and gasket thickness.

Are these pistons suitable for all engine builds?

These pistons are intended for performance Small Block Chevrolet 400ci (374 cu in) engines. They are forged from 2618 aluminum, making them well-suited for higher stress applications. However, they are not CARB approved and cannot be shipped to California.

What is the weight of each piston?

Each piston in this set weighs 436 grams. This consistent weight is important for balancing the rotating assembly in your engine.

Mahle SBC 400ci Forged Piston Set 197753325

Name: Mahle MS Piston Set SBC 400ci 4.125in Bore 3.5/3.75stk 6.125/6in Rod .927 Pin 12.3/13.1 CR Set of 8
Brand: Mahle
SKU: mahle-mahle-ms-piston-set-sbc-400ci-4-125in-bore-3-5-3-75stk-6-125-6in-rod-927-p-t14-30106
Price: 992.47 USD
Availability: BackOrder

Mahle MS Piston Set SBC 400ci 4.125in Bore 3.5/3.75stk 6.125/6in Rod .927 Pin 12.3/13.1 CR Set of 8

$992.47

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Mahle MS Forged Piston Set for SBC 400ci engines. 4.125in bore, 3.5/3.75in stroke, 6.125/6in rod, .927in pin. Set of 8.

Key Features

Fits Chevrolet Small Block 374 cu in engines.
Forged from 2618 aluminum alloy for strength and durability.
Designed for a 4.125-inch bore.
Compatible with 3.500-inch or 3.750-inch stroke crankshafts.
Works with 6.125-inch or 6.000-inch connecting rods.
Includes .927-inch wrist pins.

These pistons are designed for Chevrolet Small Block 374 cu in engines. Please verify compatibility with your specific engine configuration.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Product Details

Forged from 2618 aluminum alloy, these Mahle MS pistons are built for high-performance Small Block Chevrolet 400ci (374 cu in) applications. The 4.125-inch bore size is a common specification for the 400ci engine, and these pistons are designed to work with either a 3.500-inch or 3.750-inch stroke crankshaft, paired with 6.125-inch or 6.000-inch connecting rods respectively. The included .927-inch wrist pins are a standard size for many performance builds.

These pistons feature a dish volume of -8.9cc, which helps achieve a compression ratio of approximately 12.5:1 with a 3.500-inch stroke and 64cc combustion chambers, or 13.1:1 with a 3.750-inch stroke and the same chamber volume. This makes them a solid choice for naturally aspirated or forced induction builds where a specific compression target is desired. Each piston weighs in at 436 grams, contributing to a well-balanced rotating assembly when used as a set of eight.

It's important to note that these pistons are not CARB approved and cannot be shipped to California. Always consult your engine builder or a qualified professional to ensure these pistons meet the specific requirements of your build, especially regarding final compression ratio calculations based on your exact cylinder head volume and gasket thickness.