For decades, Ford enthusiasts have sought the ultimate foundation for high-performance builds. A common question often arises: Did Ford make a BBF (Big Block Ford) small bore motor, or perhaps a small block with a big bore? To clarify, the terminology often gets confused between the legendary “Big Block” (FE, 385-series) and the “Small Block” (Windsor/Cleveland) platforms. When racers ask about a “small block big bore” block, they are usually referring to aftermarket or Ford Racing performance castings.
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Understanding the Ford Small Block Legacy
The standard Ford small block, famously known as the Windsor (302/351), has been the backbone of street and strip performance. However, factory production blocks have inherent limitations in cylinder wall thickness. Ford Racing, now known as Ford Performance, recognized this and introduced specialized castings to push these boundaries.
The Ford Racing “Boss” Series
Ford did not just rely on standard production lines. The Boss 302 Big Bore (M-6010-B302BB) is a prime example of a factory-engineered performance block; Crafted from high-strength, diesel-grade iron, these blocks were designed to accommodate larger bore diameters than a standard 302, allowing engine builders to achieve displacements up to 363 cubic inches with increased reliability. These are not “small bore” motors; they are specifically engineered to be “big bore” small blocks.
Key Features of Performance Blocks:
- Material Integrity: Use of high-density cast iron or RMR aluminum for extreme durability.
- Siamesed Cylinders: Allowing for larger overbores without compromising water jacket integrity.
- 4-Bolt Main Caps: Ensuring bottom-end stability under high-horsepower loads.
- Deck Height Versatility: Options ranging from 8.200 (standard 302) to 9.500 (351W) deck heights.
Aftermarket Solutions
While Ford Racing provided the Boss series, companies like Dart Machinery took the concept further. Dart’s Race Series blocks offer features that factory castings sometimes lack, such as pressed-in dry sleeves and significantly upgraded oiling systems. These blocks allow for bores up to 4.165 inches, turning a traditional small block platform into a massive, high-revving powerhouse.
If you are looking for a “small block big bore,” Ford Performance and aftermarket giants have you covered. They have successfully bridged the gap between the compact dimensions of a small block and the displacement potential usually reserved for larger engines. Whether you choose the factory-backed Boss 302 Big Bore or an aftermarket aluminum racing block, the ability to build a high-displacement, reliable Ford small block is better today than it has ever been in automotive history.
