TKR1728X – Engine Rebuild Set (Not Broken-In, 21aM/aP/bM)

Product Description

This rebuild set is not broken-in. To view the broken-in version, click here.

TKR1728 – Engine Rebuild Set (21aP/21bM, Oil Bath Broken-in) 22423110 Extend the life of your Blok engine with this piston, sleeve, and rod set! If you’ve had a mishap or if your engine is worn out and has lost compression (pinch), this is a great way to breathe new life into it.

Package Contents

1ea Piston and Sleeve Assembly 22423100 1ea Piston Pin 22016000 2ea Piston Pin Retainers 21817010 1ea Connecting Rod 22425000 Build-up Parts Set(C&P)

This item is not eligible for our general warranty program.

Not Broken-In

Want to do the break-in yourself? Now you can! This rebuild set is untouched from the factory so you can perform your favorite break-in process.

We recommend idling at least two tanks through the engine with the needles fat while keeping the head temp at 200°F. Then while keeping the throttle below 50% max, run the car in a parking lot or on a flat surface for about five tanks. Then gradually increase the throttle endpoint and lean the engine until you get to about ten tanks. Always finish the break-in process on the track and be careful to not race the engine until the mechanical pinch is almost gone.

Break-in Tips

• Always preheat the engine to 200°F before starting.
• The engine tune should be fat for the majority of the process. This extra fuel is used to increase the lubrication and flush particles out of the engine. Because it’s fat, you will need to constantly monitor the temperature and make sure it is between 200 and 250°F the entire time.
• Stop the engine between each tank of fuel and make sure the piston is at bottom-dead-center. Let the engine cool to ambient temperature before preheating the engine head to 200°F and starting the next tank.
• Be sure to run 3/4 to a full gallon through the engine before racing.