How Do You Make a 200HP Twin Reliable?
When building a mighty 200HP twin, PSI performance made many modifications to let them produce 200HP from a motor that started life as a 700cc twin.
Custom cylinders were made with triple exhaust ports and plated with Nicasil lining. Extra time was spent on the crass hatch pattern to provide quick ring sealing and long term performance.
A Chrome moly billet stroker crankshaft increased the stroke 8mm and pushes the forged big bore pistons. Crank case modifications, billet machined heads and big twin pipes let the motor breathe.
With the modifications and parts PSI designed for this motor, making big power was readily obtainable. It was the lack of reliability that most big bore manufacturers are challenged with on these big bore kits that motivated PSI to contact Swain Tech Coatings.
This piston was coated with Swain’s TBC on top of the piston and PC-9 on the skirt.
Dan Swain, founder of Swain Tech Coatings developed the first successful ceramic thermal barrier coating for internal engine use in the early 1970’s. Dan spent the rest of the 1970’s perfecting the technology in his own asphalt NASCAR modified and with NASCAR Winston Cup teams. In 1981, Dan opened Swain Tech Coatings to offer performance improving coatings to high performance enthusiast.
Swain Tech specializes in developing performance improving coatings for internal engine and exhaust parts. Two cycle and small displacement motors are a natural fit for coatings. Most snowmobilers have experienced burned or scuffed pistons, rusty pipes that take a long time to warm up. These are ideal applications for Swain Tech to improve.
When pistons are sent to Swain, TBC ceramic thermal barrier coating is applied to the top of the pistons. TBC will help keep the heat where it will make more power, in the combustion chamber. TBC will protect the top of the piston from heat and hot spots so the piston top is protected against burning and detonation. Because TBC on top of the piston is reflecting heat upward, the piston and entire bottom end will run cooler and stronger. Skirts are coated with PC-9, the toughest and most durable piston skirt coating available. Unlike the coatings you see come on a factory piston that is primarily there to provide break in protection, PC-9 is meant to be a permanent coating to reduce friction between the piston and cylinder, protect against scuffing on a cold start and to give a back up form of lubrication if your primary lubrication is not sufficient or fails.
Exhaust parts are coated with White Lightning, Swain’s exclusive ceramic thermal barrier coating. White Lightning should not be confused with the cosmetic paint based shiny coatings that more and more companies are claiming to be ceramic. White Lightning is the only true ceramic thermal barrier coating available. Unlike those shiny coatings that only about .001” thick and not very tough, White Lightning is applied about .015” thick and is so tough that you would have to grind at it for a long, long time if you tried to remove it. When complete, White Lightning ceramic exhaust coating will have a white color and a textured finish. There is no better insulating coating and no coating is tougher.
With this big PSI twin, as with many modified 2 stroke engines, they just could not stop the pistons from burning up and or seizing. After working with Swain, PSI has been able to build high performance motors with piston reliability greater than what you would get from a stock motor.
As you build or rebuild your motor, Swain coatings should be at the top of your priority list. There are no other modifications you will make that will give you the power and durability gains that you will get from Swain’s coatings. At only $38 per piston, the coatings just make sense.
PSI learned what most of the other serious big bore kit suppliers have learned. If want a reliable motor, you need to work with Swain Tech to get the best performance improving ceramic thermal barrier and low friction coatings available.