Ralph,
Glow engines have bushed bearing about as wide as the pin diameter. Gas engines many times have much narrower bearings, like 1/2 D wide. In methanol engines the oil is diluted indeed, but glow engines get by because of the generous bearing surface that allows an oil wedge to operate despite the low viscosity and reduced oiliness.
If the engine has a needle big end bearing, it certainly will fail if used with glow fuel, due to the combined low viscosity oil/methanol mix, and acid combustion by-products.
Been there with an converted moki gas engine.
Point to ponder: MVVS also reverted to plain bearings in their 26cc and 35cc glow engines after initially having needle bearings.