Spark ignition gasoline and compression ignition diesel engines differ in how they supply and ignite the fuel. In a spark ignition engine, the fuel is mixed with air and then inducted into the cylinder during the intake process. After the piston compresses the fuel-air mixture, the spark ignites it, causing combustion.
1 If your skin is too sensitive, dilute tea tree oil with some baby shampoo. Add 10-20 drops of tea tree oil to 1/2 cup of baby shampoo. Use this daily to wash your scalp and hair till you get rid of itchy scalp.  You can even massage diluted tea tree oil to your scalp.
Body Care. 1  1. Check for sunburn. In the summer, especially the first bright days of summer, it's easy to get a sunburn on your scalp. 2  2. Check for head lice. The itching is due to your skin reacting to the saliva of the lice. 3  3. Chill out. Stress plays havoc with a body in general, and it can come into play on your scalp, too.