Okay, well I got a O.S. .12 CV-R and I need to know what is a good glow plug for this engine? I am running 20% fuel if that helps.

Get one from the medium to hot heat range and it should work fine

Yeah just get the O.S type plugs. But what plug you use depemds on the fuel you are using. 20%or higher nitro contents you would need a medium to cold plug. For 30% use a cold plug. For 20% a medium to hot plug will work reall well. For 10% use a hot plug.

The hotter a plug is the more power you get out of it. The colder plug retards the ignition which gives less power. If your only bashing then a cold to medium plug should work fine since you dont need that extra power that the hot plug gives you.

Hoped I helped you in some way.

Make sure whatever you get is a short plug. A standard long plug (like a McCoy MC-59) will protrude too far into the combustion chamber and may strike the piston. For 20% fuel use an A3. It is an affordable "hot" range plug.