Why different mixtures of methanol

[hotrod]

There are several issues that mixing water effect.

The water on a pound for pound basis, absorbes more energy as it evaporates than methanol does, but it evaporates more slowly.

The addition of water to the methanol does reduce its effects on seals and such if they are not fully resistant to methanol.

Methanol alone has very poor lubricating characteristics and so will cause some metals to sieze or gall when they slide against each other. The addition of water will help with this. In alcohol fuel burning engines they sometimes need to use metals that have good self lubricating effects in carburators and injectors to prevent sticking in a pure alcohol fuel, or add a special alcohol compatible lubricant in small amounts.

In high concentrations and injection rates the alcohol can act more like a fuel than a coolant. As you increase the portion of alcohol injected, your releasing more energy in the cylinder as the combined gasoline and alcohol burn. At some point the energy released by the extra alcohol can overwhelm the cooling effect of the injection system and your exhaust gas temperatures go back up.

Each engine and its tuning is some what unique so you will need to experiment a bit with it to find out what mixture and injection rate your engine and supercharging system produces the most power with.

I know one tuner in the UK that started out using the recommended 50/50 mix and discovered that on his engine he got better results with straight methanol.

Over many years it has been found that in general, injection mixtures of 50/50 or less water/methanol work best, except when severe cold requires higher mixtures for freeze protection.

Larry