Pistons are the highest stressed and the most critical part of an internal combustion engine. This is especially true for a two stroke motor. The four cycle piston only sees heat from combustion every other stroke, and in between, it has a full stroke to be cooled by the fresh incoming air. To further aid cooling, four stroke pistons are often cooled on the underside by oil spray and runs in a cylinder with no ports to interrupt the rings.
The two stroke piston sees the heat of combustion on every stroke without the benefit of a cool intake stroke or oil spray. Also, the two stroke cylinder is full of ports that attract heat, especially on the exhaust side where the hot gases flow directly over the crown on their way out of the cylinder, building even more heat in the cylinder near the exhaust port. This extreme heat can burn the little lubrication that the piston skirts see. This is why the piston is the weak link in the two stroke motor.
Despite extensive research and design improvements from the major two stroke manufacturers over the years, piston failure remains a nagging problem. How do you extend the life of pistons? Simply put, COATINGS.
Swain Tech Coatings is the original high performance coating company. They have been developing and applying high performance coatings for over 20 years and are widely recognized as the industry leader.
Swain Tech applies their ceramic TBC™ (Thermal Barrier Coating) to the top of pistons, holding heat in the combustion chamber where that heat can be used to power the motor, rather than dissipate through the piston where it can weaken and burn the piston. This allows the piston to run much cooler and stronger. Piston skirts are coated with PC-9, a low friction/anti-seize coating to reduce frictional loses and piston sticking.
To further improve the thermal efficiency of the two stroke cylinder, Swain Tech often applies TBC to the domes of the heads and the exhaust ports, keeping the heat where it is needed to make power and out of the areas that lead to failures. Expansion chambers are often coated with Swain’s White Lightning exhaust coating to keep exhaust gases as hot as possible, allowing the motor to breathe better. White Lightning is the only true performance available. This three layer ceramic coating keeps a tremendous amount of heat inside the pipes.
To get most life and performance out of your two stroke motor, Swain Tech’s high performance coatings are the most economical and beneficial modification you can add.