E85 & Spark Plugs - What Is the Best Plug?

[ethanolkaw]

Detonation: A violent explosion; also called combustion knock. This usually occurs near the end of the combustion process when highly compressed, high-temperature end gases spontaneously ignite, radically increasing the cylinder pressure. This pressure spike moves at the speed of sound in the combustion chamber, and the pressure can cause damage to pistons, cylinder walls, and the head gasket.

Pre-ignition: The onset of combustion before the spark plug fires. This is generally caused by some type of glowing ignition source such as a hot exhaust valve, too-hot spark plug, or carbon residue. Pre-ignition is especially damaging to engine components like pistons and head gaskets, since excessive cylinder pressures can occur even before the piston reaches top dead center (TDC

Pablo, I think we are both correct in what we are discussing, we are just talking about two different subjects. I copied the definitions above from an engine article to give a non biased definition of the two subjects. I am talking about detonation because on a well preped street or race engine you should not have too much concern with pre ignition due to reworked cumbustion chambers and pistons. In my case, detonation will be the issue with 40psi of boost or more. This is where Alcohol is far superior over gas!

 

[Pablo]

Detonation: A violent explosion; also called combustion knock. This usually occurs near the end of the combustion process when highly compressed, high-temperature end gases spontaneously ignite, radically increasing the cylinder pressure. This pressure spike moves at the speed of sound in the combustion chamber, and the pressure can cause damage to pistons, cylinder walls, and the head gasket.

Pre-ignition: The onset of combustion before the spark plug fires. This is generally caused by some type of glowing ignition source such as a hot exhaust valve, too-hot spark plug, or carbon residue. Pre-ignition is especially damaging to engine components like pistons and head gaskets, since excessive cylinder pressures can occur even before the piston reaches top dead center (TDC

Pablo, I think we are both correct in what we are discussing, we are just talking about two different subjects. I copied the definitions above from an engine article to give a non biased definition of the two subjects. I am talking about detonation because on a well preped street or race engine you should not have too much concern with pre ignition due to reworked cumbustion chambers and pistons. In my case, detonation will be the issue with 40psi of boost or more. This is where Alcohol is far superior over gas!

Yes, alcohol is much much better at resisting detonation. Thats partly what makes it such an awesome fuel. Just gotta make sure you keep those hot spots in check so you don't pre ignite. Don't get me wrong, I'm not trying to say that alcohol can't compete with gas. If you ask me, alcohol is much better

 

[wordy1]

I've been told by many credible sources, that the octane rating of E-85 is closer to 107-8 as the cooling effect also helps to combat detonation.

 

[Hot Air]

According to the literature, as the ambient temp drops, the manufacturers will increase the gasoline % and drop the ethanol % to promote cold starting. Be aware.
Conrad