What engine characteristics would make MULB a better choice in an air cooled motorcycle engine than than 110K?
WOBBLY:
If the engine develops only moderate cylinder pressures and has shown tolerance for lower octane fuels in the past, I'll often recommend MULB for these applications. Obviously MULB at 101 R+M/2 octane has significantly lower resistance to heat and pressure than does the leaded ERC110K at 111-112 R+M/2 octane. So I try to be sure the REOR (Running Engine Octane Requirement) is not driven upward by other factors.
Examples of these other factors:
-Poor cylinder head and cylinder cooling (air cooled engines are often trouble in this area)
-Iron rather than aluminum head(s) and cylinder(s)
-Tuner is inexperienced
-Existing tune-up is obviously poor
-Engine has not demonstrated tolerance for lower octane fuels previously
-Engine has never before been run on a reduced octane, unleaded fuel
-Rider often goes to WOT at low RPM's and is prone to lugging the engine
-Tuner is unsure of compression ratio and/or prior fuels used
If any of the above factors exist, I'll try to point the customer in the direction of ERC110K.
Note that MULB is the most heavily oxygenated gasoline we bring to Bville. It is approx 3.0% net oxy by mass and, therefore, has the most theoretical power potential of the gasoline class legal fuels at Bville. That said it's important not to misapply this fuel to applications that develop high cylinder pressures and operate with high REOR.
Note that it's very common for the hi-rpm, 4 cyl, "superbike" engines to do very well on this fuel. At Speedweek and Bub's many racers use MULB successfully.
Thanks for your question. If you have others, just let me know.
Best regards.
Rick Gold
ERC Fuels-owner