c12 in 9:1 CR SBC
 

is there any reason to use c12 in a low compression engine. any benefits, any HP increase? may run cooler if properly jetted? would a dyno show any power increase?

ken

If you don't need it don't run it . The higher octane is to stop detonation and at 9to1 you want have that problem

James is exactly right..you can over fuel a motor...meaning that too much octane can acutally slow one down...octane is used to gaurd against detonation purposes only..

Brian

thanks for the responses guys. that's exactly what i was thinking. i have never found giving an engine more octane than it requires to be useful. the reason i asked is i have a friend that races circle track and he insists he needs c12. i tell him he is wasting his time and money. oh well.......

One of the most common misconceptions about octane I come across, is people think the higher the octane the more flamable or powerful the fuel is. In reality, the higher octane actually raises the flash point, meaning higher temps are required to ignite the fuel. This is why it makes more power because it allows the engine to squeeze it more before igniting it causing a bigger bang. A low compression engine may have difficulty generating enough cylinder temp (which cylinder pressure is partialy responsible for), to completely burn the fuel, consequently reducing engine efficency.

So what they said about no benefits to it in a low compression engine! :)

A dyno should show a power loss.

If this is a street engine it should work fine on 87 octane pump gas. Maybe 89 at the most. If itr won't it is maybe a non-quench engine and will require the extra RON/MON of the 92-93 octane.

Ed

Ed is correct. We have put in the RaceGas and lost power.
Use enough octane but not crazy amounts, it hurts not helps.