Multi-piece exhaust manifolds are one of the essential elements required for any high performance application on a Dodge Cummins truck. For most diesel truck enthusiast one of the coolest things about owning such an amazing machine is the ability to turn the power way up. However, as with everything in life the bad comes with the good. More power means more heat, more heat means possible damage to the diesel engine.
Adding a high performance turbocharger (“turbo”) is a common method of effectively increasing the performance of a diesel engine. Basically, a turbo is a pump that compresses air then forces it into the engine. This increase in air pressure injects more fuel and air into the engine cylinders. The increase of fuel and air produces more power, but this compressing the air also increases its temperature. The extreme increase in temperature leads to numerous problems.
It is common for stock one-piece manifolds to be the first to fall victim of the increased temperatures. Exhaust Manifolds funnel exhaust gas from the engine into the turbo’s turbine, which rotates a fan on a shaft and powers the compressor. In such a situation exhaust manifolds are directly exposed to extreme engine heat. Stock manifolds are known to shrink significantly, causing manifold-cracking, gasket problems, and exhaust flow problems created by exhaust port misalignment.
The best way to prevent damaging a manifold or remedy damaged stock exhaust manifolds is to replace them with a high performance two-piece manifold. Such manifolds, are designed to eliminate the dreaded manifold shrinkage. Quality, two-piece manifolds are produced by a number of companies for the 3rd generation Dodge Cummins. The Diesel Power Source two-piece manifold is both a great performance manifold and a stock replacement manifold. It is forged from Moly-Bendum Ductile (which can handle extreme heat) with a CFD (Computational Fluid Dynamic) Tested, high flow engineered design that assists in quicker turbo spool-up, and increases exhaust gas efficiency. The multi-piece design eliminates warping and cracking to the manifold, that is expected to occur on all single-piece exhaust manifolds. Furthermore, quality two-piece exhaust manifolds have improved air flow allowing better fuel efficiency and increasing overall horsepower and torque.
All quality brands of two-piece manifolds will be CFD designed and flow tested and balanced for increased balanced exhaust flow, while maintaining velocity for increased turbo spool up. Include block gaskets, and two bolts. They will also have drilled/tapped for pyrometer and pressure fitting, both 1/4″ NPT and 1/8″ NPT. Manifolds should be made from Moly-Bendum Ductile, have a black high temperature coating, always come pressed together, pressure tested and ready to install.
In conclusion, because stock one-piece will warp, shrink, and crack due to high temperatures, it is highly recommended to install two-piece exhaust manifolds. Doing so will allow you to take full advantage of your Cummins engine’s awesome power and eliminate unnecessary damage.
And all this wonderful information comes from our friends at http://www.sharkdiesel.com,