Cylinder Base Nut Wrench – 5/8" | Continental Engine Tool

Make cylinder removal, installation, and engine assembly easier with this professional-grade 5/8" Cylinder Base Nut Wrench. Designed specifically to reach cylinder base nuts in tight engine compartments, its long reach and thin-wall construction provide access where conventional sockets and wrenches simply won't fit.

The generous 15-inch span reaches around most aircraft-style engine cylinders, while the 12-point box end works with both standard hex and 12-point cylinder base nuts. A 1/2" square drive allows use with a compatible torque wrench or breaker bar for proper installation and removal.

Forged from 4130 steel, heat treated for strength, and finished with industrial chrome plating, this wrench is built for repeated use during engine maintenance, cylinder changes, and complete overhauls.

Product Features

• Wrench Size: 5/8"
• Drive Size: 1/2" square drive
• Reach / Span: 15" (381 mm)
• Wall Thickness: 0.14" (3.5 mm)
• 12-point end works with both hex and 12-point nuts
• Fits all Continental and most Lycoming engines
• Long-reach design fits around nearly all aircraft-style cylinders
• Thin-wall construction provides access to tight cylinder base nut locations
• Forged from 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 requirements
  

Engine Applications

This 5/8" Cylinder Base Nut Wrench is generally used with select Continental engine applications, including:

• Continental A-65 Series
• Continental O-470 Series
• Continental IO-520 Series
• Other engine applications utilizing compatible 5/8" cylinder base nuts

Designed for Cylinder Work

The specialized curved design provides the clearance needed to reach around the cylinder barrel and access difficult cylinder base nuts. Attach your 1/2" drive torque wrench for controlled tightening during cylinder installation or use an appropriate breaker bar for removal.

Important Torque Note

When using an extension-style cylinder base wrench with a torque wrench, the effective lever length can change the actual torque applied to the fastener. Torque-wrench settings may require correction depending on wrench orientation and effective length. Always follow the applicable engine manufacturer's maintenance or overhaul procedures.

Ideal for Airboat Engine Maintenance

A valuable addition to any Continental airboat engine tool kit, especially for:

• Cylinder replacement
• Top overhauls
• Complete engine overhauls
• Cylinder base nut installation
• Engine teardown and assembly
• Routine cylinder maintenance

Size: 5/8"
Drive: 1/2" Square
Span: 15"
Material: Forged 4130 Steel
Finish: Industrial Chrome Plated