Sunnen Engine Cylinder Hone

Sunnen Engine Cylinder Hones: A Century of Precision Bore Finishing

When it comes to engine cylinder hones, few names carry the weight of history and engineering credibility that Sunnen does. In 1928, founder Joe Sunnen introduced the first manual cylinder hone to help garages achieve a more perfect bore finish — and that founding principle of uncompromising precision has guided the company ever since. Today, Sunnen's cylinder hones remain a gold standard in engine building shops, professional rebuild facilities, and maintenance operations around the world.

The AN Series: Portable Hones Built for the Workshop and Job Site

Sunnen's portable AN-series cylinder hones are the workhorses of their engine honing lineup. The AN-112 Standard Portable Hone features an adjustment range of 2.5" to 7" in diameter, and with optional Master Holders and Stone Supports, that range extends up to 15" — making it suitable for a wide variety of gasoline and diesel engine applications. It also ships with a 2" drive shaft and a 12" extension for accessing deep bores. For heavier-duty demands, the AN-815 Heavy Duty Portable Hone handles cylinders from 2.5" to 21" in diameter, delivering fast metal removal and superior surface finishes without requiring the workpiece to be removed from its location.

These portable hones bring what Sunnen describes as "industrial-grade honing performance" directly to your job site or workshop floor — a key advantage for engine rebuilders and heavy equipment repair operations that need dependable results without the footprint of a full honing machine.

Why Sunnen Cylinder Hones Produce Superior Results

What separates Sunnen's approach from basic flex-hones or budget alternatives is the precision engineering behind the abrasive stone system. Sunnen offers honing stones in a wide range of grits — from aggressive 70-grit stones for rapid material removal to fine 400-grit stones for the polished plateau finishes that promote proper piston ring seating. The result is a cylinder bore that meets or exceeds original factory specifications for roundness, size, and alignment — correcting distortion caused by wear, cap stretch, or warpage.

• Produces exceptionally round and straight bores that meet or exceed original factory accuracy
• Creates surface finishes that improve oil retention and piston ring sealing for longer engine life
• Delivers improved bore accuracy for reduced blow-by, higher power output, and lower oil consumption
• Compatible with cast iron and a wide range of cylinder materials and surface coatings
• Extensive stone grit selection (70 to 400 grit) for both stock removal and finish honing stages

Trusted Across Engine Types

Sunnen cylinder hones are not limited to passenger car applications. Their honing solutions are engineered to handle diesel engines, small engines (ATVs, lawn equipment, chain saws), and large-bore industrial applications. This versatility is a direct result of Sunnen's deep investment in research and development — from custom abrasive formulations to purpose-built tooling mandrels designed for specific bore diameter ranges.

For engine builders who demand repeatable, measurable results every time, Sunnen's cylinder hones represent one of the most proven and respected tool investments in the trade. Explore the full Sunnen brand catalog or browse all engine cylinder hones to find the right honing solution for your application.