1FZ DIAMOND PISTON 4.016 FLAT
- Model : RACING PISTONS
Even small displacement engines now produce horsepower that only ten years ago was considered the realm of highly refined and exotic mills hundreds of cubic inches larger. And sizeable cubic inch power plants regularly produce over 1,000 horsepower in street trim with a cast aluminum intake manifold and a single carburetor. There seems to be no end to the power potential. Cylinder head technology with increased air flow and combustion chamber design has led the charge. Many of these advances have been accomplished by improving the performance of the valve train, achieved largely by state-of-the-art test and development equipment such as the Spintron, and also by the latest computerized machining centers. The enthusiast community measures engine power in terms of horsepower and torque. But cylinder pressure read as BMEP and IMEP are more accurate indicators. These abbreviations refer to Brake Mean Effective Pressure and Indicated Mean Effective Pressure, which are more precise measurements since gas pressure in the cylinder varies from a maximum at the beginning of the expansion stroke to a minimum near its end. Also, these classifications can very accurately compare the power of engines of different displacements since it is the pressure per piston area that is being examined. Recognizing that cylinder pressure is the true dynamic that creates horsepower compels one to consider the piston and the forces applied to it. In high performance and racing applications the piston needs to withstand and then transfer the cylinder pressure to the crankshaft while it also maintains its shape, provides a long service life, partakes in sealing the bore, and compliments and not detracts from the effectiveness of the cylinder head and combustion chamber. That’s a long list of tasks! Over the years, the performance engine-building community has gone from using an original-equipment-style cast piston to a stronger forged design that also allows more freedom in manufacturing and a reduction in the reciprocating mass. High quality, advanced aluminum materials are employed and forged pistons are now available with outboard or with the narrower inboard pin towers. Additionally, they provide excellent load paths and rigid structures and attract an array of competent coatings to protect them. However, the forged piston has one major shortcoming: infinite design potential. If, for example, a piston designer or engine builder or race team wishes to change the piston structure or adopt different load paths or experiment with different struts and buttresses, only a billet piston will accommodate these requirements. NASCAR teams were quick to recognize the billet’s potential, taking advantage of its versatility. They continue to develop and test new designs constantly. Among piston producers, Diamond was one of the first production houses to embrace the new technology, initially making billets available to NHRA Pro Stock teams. Nonetheless, bringing a cost-effective billet piston program to the general market turned out to be a formidable challenge - often cost prohibitive and, therefore, unsustainable. In fact, the program only became viable when they established a special department with dedicated engineering staff and equipment. Once they had established the technique, however, race engine builders no longer needed to work within the confines of a forging. Many engine builders openly admit they felt they were on a short leash with any forged piston. Not being able to have it fully meet their requirements they compromised as best they could. Race teams not only openly embrace the freedom that billet pistons offer but also the ability to re-examine the cylinder head, combustion chamber and valve angle for further power gains. The possibility for another great leap in power is one of the most exciting aspects of the billet piston.