After a successful weekend of racing during the opening rounds of AMSOIL Championship Snocross over Thanksgiving weekend 2015, AMSOIL/Scheuring Speed Sports driver Lincoln Lemieux made the Pro Open final on Sunday.
Lemieux fought his way into the top-three and was running strong. But, about 14 laps into the 20-lap race, he started slowing down and losing power. He pulled off the track and drove back to the trailer.
When team owner Steve Scheuring arrived, the heat from Lemieux’s Ski-Doo RS600 engine was overwhelming. “There were parts of the engine that melted,” said Scheuring. “You could smell that antifreeze had gotten hot. Everything was just hot. That’s the best way I can describe it. Just hot.”
The crew opened the engine panels and noticed a $1 clamp had broken, separating the coolant lines and causing the engine coolant to pump from the system. Further inspection revealed intense heat had melted the exhaust power valve covers. The rubber O-rings that separate the cylinder from the head also melted, which caused the engine to lose compression and power. “There were a few other gaskets that actually melted inside the motor,” said Scheuring.
In stock condition, the engine produces about 130 hp, but the team relies on piping, clutch, carburetion and other modifications to increase power by 20 percent. “We can’t do anything to the internals of the motor, so we need to take every one of the options we have and bring them right to the edge,” said Scheuring. The modifications and lack of coolant exposed the engine to intense heat “well in excess of beyond operating temperatures,” Scheuring said.
“In a normal situation when something like this happens, the motor will lock up because of the high temperatures. The rings will stick to the piston. The pistons will score the cylinder walls. There’s a good chance the crank bearings will seize,” said Scheuring.
Instead, the rings and pistons were still free and the crankshaft still turned freely. “We saw some minor [piston] scuffing,” said Scheuring, “and it was like, ‘this is crazy how well the inside of this motor looks.’”
Each one of Scheuring’s Ski-Doo engines makes up a big portion of a race sled’s high cost. “We could take this motor, put new gaskets in it, put new exhaust valve covers on it and go racing,” said Scheuring. “We go above and beyond the capabilities of these motors. If they fail they cost us money, they cost us time and they cost us races, and we can’t afford to lose any of those.”
Scheuring credits AMSOIL DOMINATOR® Synthetic 2-Stroke Racing Oil with saving his engine. “We’ve worked with AMSOIL the last 20 years developing two-stroke oils for our race sleds,” said Scheuring. “In my opinion, I believe 100 percent the reason that motor lived was because of the AMSOIL products.”