This is the most common rubber belt, it is commonly used in mild applications with 4-71 thru 6-71 blowers with drive ratios up to 15% overdrive. With higher drive ratios and larger blowers this may cause this style of blower belt to jump teeth or break.
8MM, HTD "ROUND TOOTH" BLOWER BELT:
The 8mm rounded tooth style rubber power grip belt is capable of transferring more horsepower than the 1/2 pitch style. The 8mm belt is used in all blower applications running 15% and up to approximately 35% overdrive. When higher drive ratios are used it can shorten the belt life expectancy.
13.9MM, & 14MM HTD "ROUND TOOTH" BLOWER BELT:
The 13.9mm and 14mm rounded tooth polychain is the strongest style blower belt available. These belts are designed for high performance competition style blower systems and are used on the majority of top alcohol and top fuel racers. These belts are manufactured from a special polyurethane material lined with kevlar for maximum strength.
Never use a 13.9 mm pulley with a 14mm belt or vise versa.