What is the Best Engine Assembly Lube?

The best engine assembly lube is the one that is going to protect your engine during the crucial few moments after it’s initial start-up.  To understand what makes for a good assembly lube, it’s important to understand everything that is going on when you first start a new or rebuilt engine.

What happens During Engine Break-in?

  • Piston rings seat
  • The oil pump starts working
  • Camshafts break-in


engine, engine assembly lubeWhen your motor was put together the piston rings were custom fit to each piston and cylinder to ensure a good seal.  Also, the cylinder walls were honed leaving a slightly rough surface.  The new rings will run on the cylinder walls which will both seat the rings and start to smooth the cylinder walls.  Seating the piston rings the right way will ensure a good seal and maximize engine efficiency.

Just like every time you start your engine, it takes time for the oil pump to grab oil out of the sump, pressurize the oiling system and get the oil out to the bearings and other parts of your engine to lubricate them.  After break-in in, the system will be filled with oil, and wear surfaces will be coated with oil so proper lubrication happens much more quickly after startup.  During break-in, you need the break-in something to lubricate things until your oil can get there and do its job.  One thing most people don’t consider is that the assembly lube will get washed into the engine oil during the first minute of operation. Besides being a good lubricant on startup, your engine assembly lube needs to be compatible with your engine oil and should not significantly reduce or increase its viscosity.

The last thing that happens during break-in, especially on motorcycle engines, is that the camshaft will get broken in.  In every motor, there is something the camshaft lobe moves to actuate the valves.  This can be a flat tappet, a lifter, a rocker arm, or shimmed bucket.  On most camshafts, the first few minutes of operation after installation will determine how the camshaft lobe will interact with the valve opening device.  If the camshaft doesn’t get broken in correctly you can quickly damage your cam or create a situation where the cam lobes will wear out quickly.  Using a good engine assembly lube and breaking in your camshaft per the manufacturer’s instructions is the best way to ensure long camshaft life.

PJ1 Engine Assembly Lube is a superior assembly lube that can help with all of these critical events during engine break-in.  PJ1 Engine Assembly Lube can be applied directly to piston rings to ensure the right environment for optimal break-in.  It also can be applied to all other surfaces in your motor or transmission during assembly to ensure proper lubrication until your oil pressure comes up and the oiling system is lubricating your motor.  PJ1 Engine Assembly Lube will not affect your oil during break-in so much so that it can be left in your oil after your initial start.  Lastly, PJ1 Engine Assembly Lube comes in an easy to use spray can rather than a tube so it is easy to dispense it exactly where you need it without excess build-up.  If you’re building a motor use PJ1 Engine Assembly Lube to protect your investment and give you confidence on your first start.

Photo by Phong Nguyen