Tech Tip: Piston Pin Spiro Lock Installation Procedures – UnderhoodService

Tech Tip: Piston Pin Spiro Lock Installation Procedures

When the locks are properly seated, only half of the lock will be visible above the groove. Most pistons that require spiral locks will need four locks per piston, two at each end of the pin (check with your piston supplier). When installing Spiro locks, grip each end of the lock and pull apart (approx. 3/8"-7/16"). The lock will resemble a small coil. The lock can then be spiraled into place almost as if you were screwing them into a groove.

When the locks are properly seated, only half of the lock will be visible above the groove. Most pistons that require spiral locks will need four locks per piston, two at each end of the pin (check with your piston supplier).

When installing Spiro locks, grip each end of the lock and pull apart (approx. 3/8˝-7/16˝). The lock will resemble a small coil (Figure 1). The lock can then be spiraled into place almost as if you were screwing them into a groove (Figure 2).

WARNING: It is important that the correct numbers of locks are installed in each piston or severe engine damage may occur. Do not over stretch Spiro locks and do not reuse Spiro locks.
Figure 2
Tech Tip courtesy of JE Pistons.

You May Also Like

Lifter Deactivation

The area of contact between the lifters and cam lobes is the highest loaded surface inside an engine.

The basic function of a valve lifter is pretty simple. It sits on the camshaft and transfers the motions of the cam lobe up through the pushrods and rockers to open and close the valves. The size and shape of the cam lobe under the lifter (multiplied by the ratio of the rocker arms) determine valve lift and duration. As such, the lifter just follows the motions of the cam. But, it does play a role in valvetrain lash (clearance) and noise.

Alternator Testing For No Charge Conditions

Many alternator problems turn out to be nothing more than a bad connection at the alternator or a bad wiring harness.

Understanding Coolants

All-season coolant used inorganic acid technology and worked great for almost 30 years.

Ignition System Do’s and Don’ts

Why do ignition systems give technicians problems when diagnosing ignition-related misfires? The answer is that some technicians use tests that might give inconclusive results or do damage to the coil or drivers inside a module.

Tools To Service Serpentine Belts

Servicing the serpentine belt on some vehicles is a tough task.

Other Posts

Battery Charging and Diagnostics

Here are six tips to use when diagnosing a vehicle with a dead battery. 

Why Do Timing Chains Stretch?

As the timing chain wears, it can change the timing of the camshaft and crankshaft.

Carbon Deposits and Direct Injection Engines

The primary cause of these problems is that fuel and added detergents are not hitting the back of the intake valves.

Acura Turbo Engine Service

It is important to check the operation of the solenoids that control vacuum to the actuators.