Update
I came across some tuning information that pretty much backs up my theory and prior research discoveries (readings) about the propensity of methanol to preignite under certain circumstances when used with gasoline. It explained the phenomenon very well. I'll try to relay it in a manner that will be easy to understand.
All fuels have a temperature limit where they will autoignite (preignite) without the need of an ignition source. Gasolines are blended in various ways to give each blend a certain burning characteristic for a certain operating window. Part of that operating window is the temperatures that the fuel will be working under in the intake manifold, cylinder, during compression and during combustion.
Methyl alcohol (methanol) is not a blend of different liquids. It is a mono-liquid. The operating parameters that methanol works under is consistent and rigidly set. Where as with gasoline, you can end up with different batches of a particular type of fuel (ex., 91 octane pump gas) that will work differently due to variations in the blending process or seasonal blends.
Gasoline fuels typically operate within a certain temperature range. Different engine configurations will have their own temperature operating range as far as fueling requirements go. Gasoline fuels are accordingly blended to operate within these different temperature ranges and it's up to the tuner to pick the right gasoline to use to match to his engine configuration and operating parameters.
Gasoline engines typically operate at intake, cylinder and combustion temperatures that are significantly higher than methanol fueled engines. When methanol is being used along with gasoline, there is the chance under certain tuning conditions where the intake and/or cylinder temps can get high enough to autoignite the methanol in the charge mixture.
The types of tuning conditions can be: high hp/cid, high boost, high dynamic CR, inadequate intercooling, inefficient turbocharger, incorrect timing, a/f mixture too lean, hot engine. Basically, anything that can get intake or cylinder temps up to the autoignition temperature where the methanol will preignite.
The methanol assists in controlling intake, cylinder and combustion temperatures, but remember that the gasoline plays a part in that too.
An example that was given was where a fellow was using a gasoline/methanol mix and decided to lean the gasoline down a tad bit. An intake backfire occurred blowing the blower intake manifold apart. The interesting thing is, the spark plug only showed one thread heat colored.
I see a problem with running C16 with methanol. C16 allows higher boost limits due to it's resistance to detonation under high pressures and temperatures. This in turn allows the engine to be pushed harder and net higher hp/cid levels. Along with that higher hp/cid comes increased thermal loading of the engine. Higher temps. But,... what are those temperatures? How close is it getting to the autoignition limit of the methanol?
Yes, methanol can resist a lot of compression and pressure, as long as the temperature factor is closely controlled.
There is a wall that you fellows will discover on your own where the power levels per cubic inch are just getting too high for the gas/meth mix. I believe this thread is showing us some evidence of it.
.....thanks Bob
