Great, this clears things up a little for me. Will i benifit from using a racing type gas sold at the local drag strip or will the amaco 93 octane work best? I also want to send my engine out to be modified, is there anything that needs to be done or not need to be done as far as mods for this fuel to work its best. I need to have very good throttle response. As i stated before, this engine is in a drag boat where you start from a stand still and run hard for 264 feet( 1/5 SCALE QUARTER MILE). I need lots of power for a short time, i have even looked at the rc nitrous oxide kits from nitrous express. Thanks everyone for setting me straight on this, yall are great. Frank