Making a naturally aspirated engine will produce considerable horsepower, not only requires pure displacement, but also requires a good set of cylinder heads that can move air. For our Cruncher Firebird project, we used a set of Dart Pro1 LS 12-degree 285cc CNC cylinder heads, and Pro1 single plane LS7 to provide some unusual power.
The brackets are consistent with the game name in the index competition, because that is why we use Project Number Cruncher, because only naturally aspirated combinations are meaningful. We plan to use the Dart LS cylinder block as the basis for engine manufacturing. Therefore, we also use a set of cylinder heads. Dart’s air intake will surely provide us with a proven and guaranteed combination. By matching the Pro1 cylinder head and intake port, it saves us time trying to combine another high-end component and CNC machining to maximize its performance.
When General Motors released the LS7 as an engine option, it could generate more than 500 horsepower and 470 pound-feet of torque without a booster. This makes the engine ideal for those who like naturally aspirated horsepower, and provides a good foundation for companies like Dart to create some evil new hardware. From the beginning, Dart saw the LS7 cylinder head style as a way to help any street or racing car get a lot of reliable horsepower.
When Dart began the design process of the Pro1 cylinder head, it wanted to ensure that the cylinder head had sufficient strength, so it chose high-quality HIP aluminum alloy as the base material. These 285cc rectangular port heads are fully CNC machined and have large 2.200/1.625 inch valves in a 66cc combustion chamber. To clear these valves, they must be used on engines with cylinder bores of 4.125 inches or larger.
On a set of reserve LS7 cylinder heads, the power of the combustion chamber is 70cc, but the Pro1 cylinder head has changed this. Mike Sanders of Dart explained why the Pro1 nozzle actually reduces the combustion chamber.
“Before creating these heads, we had many ideas on how to improve them. The combustion chamber was designed to increase overall flow characteristics and promote efficient flame propagation for maximum adjustability. The specially designed 66cc chamber volume can be used for most Shelf piston, and allows multiple pumping compression ratios.”
Except for the size of the combustion chamber, the valve angle of Dart’s Pro1 nozzle is different from its original cousin. When the LS series engine was released, its valve angle was 15 degrees, which is an improvement over the standard 23-degree small Chevrolet valve angle. By changing the valve angle, the way air flows into the combustion chamber can be greatly improved. This improves efficiency, which means more horsepower.
Sanders believes that there are two main reasons for Dart’s decision to stand up more valves in the Pro1 cylinder head.
“The 12-degree valve angle and 2.200-inch valve diameter increase the line of sight from the port opening to the valve seat, thereby improving port efficiency. It also allows OEM and after-sale valve train components to be used in factory or high-performance applications.” He explained .
Before creating these heads, we had many ideas on how to improve these heads. –Mike Sanders of Dart Machinery
The flow pattern of a set of cylinder heads is important, but in a naturally aspirated combination, it becomes crucial if you need a lot of power. Dart wants to ensure that the flow of Pro1 heads is greater than the inventory of a set of LS7 heads, so it did a lot of research before releasing the heads. The focus is on the port volume and the cross-sectional area of the head. This is done in order to be able to generate sufficient air velocity and also maintain a non-turbulent air velocity. This creates a situation in which the air in the cylinder fill is maximized through the flow curve of Pro1.
You can purchase a set of Pro1 LS7 heads from Dart. These heads are already assembled and can be completed with a rocker of your choice.
Dart’s Pro1 LS7 head series has many variants, of which the full competition version is the most radical version.
“We provide a fully CNC racing version with brass seats and Jesel machining. We moved the .030 inches closer to the valve to optimize the valve train geometry. This is at the high RPM and speed associated with power booster applications. The stability of the valve train is improved during periods of high cylinder pressure. In addition, our 285cc intake and 104cc exhaust cross-sectional areas can be perfectly matched with naturally aspirated, nitrous acid and turbocharging applications.” Sanders explained.
If you want to achieve maximum horsepower, it is very important that a set of cylinder heads and intake ports work together. In order to achieve this goal, Dart has developed its own intake port to match the Pro1 LS7 cylinder head: LS Pro1 single plane LS7 intake port.
By adopting a two-piece split design for the Pro 1 air inlet, Dart can ensure that all key areas of the air inlet are massaged for optimal airflow. If you want to control the air inlet yourself, Dart will provide the air inlet in a cast state. If you want to deliver fuel along this route, you can also order all the bosses to be machined for fuel injection.
When perfecting the engine air intake system, the name of the game is the ability to expel air into the cylinder head. Dart hopes that the Pro1 intake port bends and bends as little as possible, so that the air is directly shot to the cylinder head port through the flow passage of the intake port. This requires a lot of research to understand how to make full use of the air chamber volume, port shape and runner angle of the Pro1 intake chamber.
“The use of a two-piece design is beneficial because we can separate the two halves and efficiently CNC transplant all areas through better cutting paths and steps. The shape of the valve, the volume of the air chamber and the angle of the flow channel are designed to maximize It greatly improves the air flow, fuel distribution and valve sight line, which complements our Pro1 LS7 cylinder head. The complete CNC port can achieve more consistent flow channel volume and port shape to achieve consistent and repeatable adjustments. ”
A complete CNC port can achieve a more consistent flow channel volume and port shape, thereby achieving consistent and repeatable adjustments. –Mike Sanders of Dart Machinery
LS engines based on hav3 have many different intake designs. The air intake you decide to use should match your specific application so that you can get the most power from that combination. Dart researched why the single-wing intakes performed so well in drag races and ensured that all these functions were integrated into the Pro1 intakes.
The single-sided intake manifold has a larger air chamber volume. In some cases, depending on the air chamber design, the runner length is shorter. They started mixing fuel and establishing airspeed at a higher RPM, making it ideal for drag racing applications. If you are mold cast or fully CNC transplanted, our manifolds are perfect for drag racing. “Sanders said.
The team of Automotive Mechanics and Institute of Technology (SAMTech) designed a Dart-based engine for Project Cruncher. They know how important it is to use a set of heads and air intakes to flow large amounts of air for a naturally aspirated engine like the one we will use in Firebird.
“Dart is a leader in the development of aftermarket engine parts. By using its parts, we will be able to optimize the airflow into the engine while achieving maximum casting integrity. Strong airflow and airspeed are essential, but sometimes maintaining power may be more important Important. Therefore, the combination of airflow, airspeed and casting integrity is critical to maximizing the performance of this type of engine.” said Shawn Hooper of SAMTech.
Dart Pro1 LS7 cylinder head and intake manifold are the perfect match for our Dart LS cylinder block. When SAMTech is finished with an engine, this combination of parts should help Project Number Cruncher create a naturally aspirated suction material. As we understand the construction of the engine and its performance on dyno, make sure you follow Dragzine.
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Post time: Oct-09-2020