Engines Examined After California

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Per ARS (http://autoracingsport.com/nascar/un...ascar-engines/)

Doug Yates has had a chance to pull apart and examine the engines from the first two races in the unleaded era, and he sees some challenges ahead. In fact, Yates said, his engines came within, say, 10 laps of wholesale failure in unleaded’s debut at California.

“We came back from Fontana and every engine we had was almost broken,” said Yates, chief of Roush-Yates Engines, which produces all motors for Ford’s NASCAR fleet. “Some were broken and just didn’t fail on the track. The 21 car [Ken Schrader] broke. #99-Carl Edwards’s engine was broken and he didn’t even know it. It must have broken coming to the checkered flag or on the way to the garage. “I’ve talked to the other engine builders in the garage, and they say this is a way bigger challenge than we all thought it was going to be.”

NASCAR has used unleaded gas in the Craftsman Truck and Busch Series for a few years [actually started in 2006]. It decreed last year that unleaded would become the mandate beginning at California this year. The California and Las Vegas races were the laboratories. Yates said he saw few problems with valves and valve seats, which had been thought to be most vulnerable with the new fuel. Lead has lubricating properties, and unleaded fuel deprives the engine of much of that inherent lubricity. But it goes much deeper than that.




“What people don’t understand is anything you change in these engines is a big deal,” Yates explained. “I’m getting tired of hearing people on TV saying, ‘Oh, it’s just unleaded fuel.’ It’s a very hard change for the engine guys. The initial thing was valves and valve seats; that continues to be a problem. But what people don’t understand is they reduced the octane from 112 to 98. Whenever you reduce octane, the fuel burns faster, so now you’re microwelding rings, breaking pistons, having [fuel] distribution issues. It used to be when you lowered the octane, you lowered the compression. Well, obviously in racing, you’re not going to lower the compression, so the tuning of the engine is probably the toughest thing.”

Doug, son of legendary team owner Robert Yates, studied engineering at North Carolina State, and he admits the change to unleaded has been a major mental puzzle. “I should have gone for my master’s,” he said with a smile.
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