The Lycoming Cylinder Base Stud, designated by part number 67U20608, is an indispensable structural component within the Lycoming O-540 series aircraft engines. Its primary function is to securely fasten the cylinder assembly to the engine crankcase, transferring the immense forces generated during combustion and ensuring the structural integrity of the engine's power section. This stud, along with others, forms a critical connection that withstands significant tensile loads, vibrations, and thermal cycling, directly impacting engine reliability and safety.
Specifications
- Part Type: Cylinder Base Stud
- Manufacturer: Lycoming Engines
- Material: High-strength alloy steel, typically heat-treated to achieve specific tensile strength and fatigue resistance properties required for engine applications.
- Finish: Commonly features a protective coating, such as cadmium plating or phosphate coating, to inhibit corrosion and improve thread lubricity during installation.
- Thread Type: Precision-rolled threads on both ends, designed for specific engagement with the cylinder base nuts and the crankcase threads. The exact thread pitch and diameter are specified in Lycoming maintenance manuals.
- Overall Length: Specific to its application within the O-540 engine series, designed to achieve optimal thread engagement in both the crankcase and
- Stock: Out of Stock - On Backorder
- Manufacturer Part #: 67U20608
- Part#: 67U20608
Aircraft Fitment Finder
Returns & refund summary
- 30-day return window — with prior return authorization, unopened in original packaging.
- Restocking fee: 20% on unopened items, 30% on open-box items.
- Refund processing fee: 5.51% applies to all refunds (returns, cancellations, core-fee refunds) regardless of reason.
- Return shipping: paid by buyer.
- Non-returnable categories: installed/used parts, special-order or rebuilt items, programmed items (incl. ELTs), batteries, AOG-priority orders, international orders.
Full terms: Return Policy.
Authenticity & authorization
All parts sold by American Aviation Parts are genuine factory products sourced through authorized distribution channels. Our authorization status varies by brand — for some brands we are a direct authorized dealer; for others we are an independent reseller through authorized distribution. Either way, the part you receive is the same factory product, with standard documentation available on request.
See our full Manufacturer Authorizations page for the current per-brand status.
Need traceability paperwork?
If your installation requires FAA Form 8130-3, manufacturer Certificate of Conformance, or other traceability documentation, please call 1-877-722-8727 or email [email protected] before placing the order so we can confirm what is available for this part.
Shipping
Standard ground, expedited, and AOG shipping options are available at checkout. Full shipping-cost tiers and timelines are published on our Delivery Information page.
