Octane number or octane rating

[sedanman]

Just some info here. Ever wonder how the octane rating of a fuel sample is determined? One method involves a variable compression ratio engine, a big piece of lab equipment. The engine has a crankshaft that can be moved closer to or further away from the cylinder head thus altering compression ratio. A sample of fuel to be tested is run in the machine until it knocks. From here the compression ratio is locked until the test is complete. Then 2 control fuels are blended to gether to acheive the same knock, the mix of the 2 fuels tells the technician the knock rating of the fuel samle. The 2 control fuels are iso-octane which is very resistant to knock and heptane which knocks readily. In this example the octane number of the sample fuel equals the percent of iso-octane need in the control fuel blend to acheive the same knock. The engine in the link below is about a 1/4 million dollars.

http://www.waukeshaengine.com/inter...lications/products/fueltesting/f1f2.cfm?r=973

 

[MasterBlaster]

With moonshine they use gunpowder.

 

[tony marks]

think ill buy meone o them for my ztr..
recon itll out power a 20 kohler command.. mines being rebuilt as we speak..