Cylinder Base Nut Wrench – 1/2" | Continental Engine Tool

Designed for cylinder removal and installation, this professional-grade 1/2" Cylinder Base Nut Wrench provides the reach and clearance needed to access difficult cylinder base nuts on a wide range of Continental engines.

The 15-inch span reaches around the cylinder barrel, while the extra-thin 0.14" wall allows the wrench to fit into tight areas where conventional sockets and wrenches cannot. The 12-point end works with both hex and 12-point nuts, and the 1/2" square drive allows connection to a compatible torque wrench or breaker bar.

Forged from 4130 steel, tempered for strength, and finished with industrial chrome plating, this wrench is built for repeated engine maintenance, cylinder changes, top overhauls, and complete engine rebuilds.

Product Features

• Hex Size: 1/2"
• Drive Size: 1/2" square drive
• Span: 15" (381 mm)
• Thin Wall: 0.14" (3.5 mm)
• 12-point end fits both hex and 12-point nuts
• Long-reach design fits around most engine cylinders
• Thin-wall construction provides access to tight cylinder base nut locations
• Forged from high-strength 4130 steel
• Tempered for maximum strength and durability
• Industrial chrome plating improves surface hardness and corrosion resistance
• Quality tested to meet or exceed engine manufacturer torque specifications
  

Continental Engine Compatibility

Fits 1/2" cylinder base nuts commonly found on:

A-Series: A-50 • A-65 • A-75 • A-80
C-Series: C-75 • C-85 • C-90 • C-125 • C-145
O-Series: O-200 • O-300
GO-Series: GO-300
E-Series: E-165 • E-185 • E-225
IO-Series: IO-360

Fitment Note: Verify your cylinder base nut size before ordering, as configurations may vary

Ideal for Engine Maintenance

A valuable specialty tool for:

• Cylinder removal and installation
• Cylinder replacement
• Top overhauls
• Complete engine overhauls
• Cylinder base nut removal
• Proper cylinder base nut torquing
• Engine teardown and assembly

Important Torque Note

When a cylinder base wrench is used as an extension of a torque wrench, the effective lever length may change the actual torque delivered to the fastener. Follow the applicable engine manufacturer's torque procedure and account for the extension when required.

Airboat Solutions

An excellent addition to the toolbox for anyone maintaining or rebuilding Continental-powered airboat engines, especially the popular E-185/O-470-family heritage engines and O-300 applications where specialized cylinder tooling is often required.

Size: 1/2"
Drive: 1/2" Square
Span: 15" (381 mm)
Wall: 0.14" (3.5 mm)
Material: Forged 4130 Steel
Finish: Industrial Chrome Plated