The Mazda team successfully built their new engines on the basis of improving compression rations. The significant boost of up to 14:1 from the previous 11:1 within a 2.9 liter is a smart and innovative way to gain more work from the power stroke of a piston. Doing so is a double edged sword as it has the potential to create work problems when the engine starts to heat up so to combat this possible scenario, Mazda has decided to use high length 4-2-1 exhaust headers, which are designed to prevent hot exhaust gas from entering the intake stroke of the following cylinder. The custom modifications on the Sky series has made it longitudinal, making it a challenge to fit this current engine model on other popular Mazda series such as the Miata.
Additional add-ons include the installation of direct injection and heat loss minimization because too high of a heat can be a problem but heat, in itself is Important to burn fuel efficiently and lowering the temperature too much becomes inefficient. The heat-loss reduction system originates from a piston shape bore that uses a cavity directly in the center, where the spark plug fires. Another important development in the engine is the reduction of piston friction as well as in the crankshaft and rods by using forged steel versus conventional cast iron. The S Series makes use of 0W20 oil and gets electronically varied dual variable valves on the intake so rapid starts can be done even in cold temperatures. There has also been a lot of thinning made which reduces the weight of the engine by 15 pounds.