S&S Cycle Engine Piston Top Dead Center Locator Tool

S&S Cycle Top Dead Center Locator Tools: Precision Built for V-Twin Engines

When it comes to engine assembly and performance tuning on V-twin motorcycles, few steps are as foundational as accurately locating top dead center (TDC). Get it wrong, and every subsequent measurement — cam timing, ignition timing, crankshaft positioning — cascades into error. Get it right, and you have a rock-solid baseline for any build or modification. S&S Cycle, the legendary American powersports manufacturer, brings that same obsession with precision to their TDC locator tool lineup.

A Brand Built on Engine Accuracy

S&S Cycle has been engineering high-performance motorcycle parts since 1958, and their understanding of V-twin engine geometry runs deep. Founded by George J. Smith and Stanley Stankos, the company started by selling high-performance pushrods for Harley-Davidson motorcycles and today still makes parts for a variety of V-Twin bikes. That long heritage of internal engine work means S&S doesn't just make performance parts — they make the tools their own engineers rely on to build and validate those parts.

What Makes the S&S TDC Locator Stand Out

The S&S TDC tool is invaluable when dialing in cams or performing any of a number of checks and modifications based on the position of the crankshaft, and it makes it easy to find exact top dead center of any engine. Rather than relying on rough visual estimates through the timing port, this tool threads directly into the spark plug hole and provides a positive mechanical stop against the piston crown, giving you a definitive, repeatable reference point every time.

S&S offers two part numbers to cover the most common engine configurations: PN 53-0321 for engines using 14mm spark plugs and PN 53-0322 for engines using 12mm spark plugs. This dual-fitment approach ensures that whether you're working on a classic Big Twin or a Sportster-style motor, there is an S&S TDC tool sized correctly for your cylinder head.

Both versions are Made in the U.S.A., consistent with S&S Cycle's commitment to domestic manufacturing quality.

When You Need This Tool

This tool is the best way to calibrate your degree wheel when dialing in cams or performing any of a number of checks and modifications based on the position of the crankshaft. Specific use cases include:

• Setting camshaft timing with a degree wheel during engine builds or cam upgrades
• Verifying ignition timing reference points
• Confirming piston position during top-end inspection or rebuild
• Any performance modification where exact crankshaft position is a critical input

For builders and mechanics who already trust S&S Cycle for cams, carburetors, and complete engines, adding their TDC locator to the toolbox is a natural extension — it's the same precision philosophy applied to the specialty tool that makes all those other components work correctly together.

Browse the full range of Engine Piston Top Dead Center Locator Tools or explore everything S&S Cycle has to offer across their complete catalog of V-twin performance parts and specialty tools.