Engines and Components› Engines, Blocks and Components

Dart

SB Ford 4.125" Bore 3.40" Stroke Forged Piston Short Block Engine

$6,650.95

SKU: CNC-9440-ED

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Overview

The Dart CNC-9440-ED is a short block engine designed for SB Ford applications. It features a Dart SHP block, an Eagle 4340 forged steel crankshaft with a 3.400-inch stroke, and Eagle H-Beam connecting rods with a length of 5.400 inches. The engine is equipped with JE forged -14cc dish pistons for a 4.125-inch bore.

This short block is internally balanced and includes high-performance plasma moly piston rings, ACL/Clevite 77 rod and main bearings, Dura Bond cam bearings, Dura Bond finishing kit, and brass freeze plugs. It also comes with a Victor rear main seal. The compression ratio varies depending on the combustion chamber volume: 10.4:1 for 56cc, 9.9:1 for 60cc, and 9.5:1 for 64cc.
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The Dart CNC-9440-ED is a meticulously engineered short block engine built for SB Ford applications, offering a robust foundation for high-performance builds. This assembly showcases a Dart SHP block, paired with an Eagle 4340 forged steel crankshaft featuring a 3.400-inch stroke and internal balance. Supporting this are Eagle H-Beam connecting rods, measuring 5.400 inches in length and equipped with ARP 8740 bolts for enhanced durability. At the heart of this short block are JE forged pistons, specifically designed with a -14cc dish to achieve a 4.125-inch bore. This configuration, along with high-performance plasma moly piston rings, ACL/Clevite 77 rod and main bearings, Dura Bond cam bearings, a Dura Bond finishing kit, and brass freeze plugs, ensures optimal performance and longevity. The engine also includes a Victor rear main seal. The compression ratio is tailored to combustion chamber size, offering 10.4:1 with 56cc chambers, 9.9:1 with 60cc chambers, and the advertised 9.5:1 with 64cc chambers. Each short block is professionally machined, balanced, assembled, and blueprinted in-house by CNC-Motorsports, with a balance card and blueprint sheet provided to the customer. This attention to detail ensures that the short block meets race-winning specifications. The standard bore is maintained unless otherwise noted, and CNC-Motorsports offers custom build options to meet specific customer needs.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

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Specifications

BrandDart
Part NumberCNC-9440-ED
CategoryEngines and Components
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Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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