Alternative Fuel School Buses

THE TECHNOLOGY

If you saw a propane bus on the street, you probably wouldn’t know that it was any different from a diesel bus, except that you wouldn’t see any black exhaust and you would notice that it was much quieter. School bus drivers, when they get their hands on the wheels of a propane bus, never want to let it go.

But the real difference is in the inner workings. Roush, Ford Motor Company and Blue Bird Corporation have combined their technologies to create a new generation of school bus that is as easy on the taxpayers’ wallet as it is on the environment.

For starters, liquid propane is used instead of diesel or gasoline. Special fuel injectors are used to inject liquid propane into the cylinders of a modified Ford 6.8L engine. The Ford 6.8L engine is standard in more than one million vehicles on the road today and is proven durable and reliable. This engine is 100% EPA and CARB compliant, and up to 50% more quiet diesel engines..

The buses use Ford’s 6R140 transmission, Ford’s most robust transmission. The transmissions feature a one-piece bellhousing, high-capacity turbine damper and torque capability nearly double that produced by that 6.8L engine. It’s a perfect pairing with the ROUSH CleanTech fuel system for school buses.

 

SAFETY

The ROUSH CleanTech fuel system is fitted with safety devices and shut-off valves that function automatically if, in the rare event, a fuel line is compromised. Propane autogas is a closed-loop system, meaning the fuel is never exposed to air and will not spill. But if it ever did, the gaseous fuel would simply dissipate in the air rather than pool on the ground like diesel and gasoline.

The propane autogas fuel tanks are mounted between the 50,000 psi steel frame rails for optimum protection. In addition, the tank mounting system is designed at twice the requirement specified by the National Fire Protection Association to ensure the tank remains securely attached.

The tanks are 20 times more puncture resistant than gasoline tanks and operate at a low 200 psi.

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