Berryman B-12 Chemtool Fuel System Cleaner (part #0116) will clean intake valves when used as a fuel additive. For piston crown and combustion chamber cleaning, 0116 is more effective as a soak. To use it in this manner, remove the spark plugs and pour in enough B-12 Chemtool to cover the entire piston. With V-configured motors, we recommend jacking up one side of the vehicle to bring one bank of cylinders to a more vertical orientation and thereby cut back the amount of product required. Depending on the diameter of your pistons and the orientation of your cylinders, it may take nearly a full bottle of 0116 per cylinder to ensure that you cover the entire crown. Note that Berryman B-12 Chemtool Fuel System Cleaner is also available in a 1-gallon size (part #0101).