The primary difference is material – which is seen in the product name. Plastic baffles are made from a proprietary plastic used most commonly in automotive radiators and therefore works well with temperatures most often seen in plastic injection molds. There are temperature limits, however, for Turbulent Flow Plastic Baffles, as we do not recommend using Turbulent Flow Plastic Baffles in coolant application temperatures that exceed the regional boiling point of water (typically 100°C or 212°F, but may be lower at higher elevation). Because of this limitation, we do not recommend using Turbulent Flow Plastic Baffles with oil or oil coolant. For more information on warnings as well as recommended installation instructions, please refer to the Installation Information for Turbulent Flow Plastic Baffles.
Turbulent Flow Plastic Baffles are also unique in two other features: First, there small “wipers” that are molded into the blade design and are designed to slightly deform during installation and turning of the baffle blade within the coolant circuit hole. The wipers are designed to reduce water “blow by”, that is, water that finds its way around the side of the baffle, a problem for some mold makers who use brass baffles but have a coolant channel that is oversized enough allow water to pass the side of the blade. It is possible to machine a tight tolerance coolant channel hole and obtain improved flow in a cooling channel, but this will translate into higher machining costs. The wipers found on the plastic baffle will be more accommodating for normal tolerances seen in gun-drilled coolant channels or circuits.
The other unique feature that is found in the Turbulent Flow Plastic Baffles, is that small “chevrons” are molded up the length of the baffle blade. These chevrons are small, crescent-shaped protrusions that force the water flowing past these features to take on a turbulent flow pattern, which is ideal for heat transfer from the surrounding steel into the water.