The sections of this manifold are pre-joined or "Sealed." This means all three components have been perfectly aligned on a jig and glued together at the factory in order to allow the manifold to be machined absolutely flat on both sides. You will not need to connect the sections upon installation. It is important to understand that the sealer used is intended to hold the pieces together for production purpose only and not intended to stop temporary leaks between the manifold sections.
Kit includes the following components:
1 qty Single Piece Exhaust Manifold Assembly (Replaces Front Section 23511221, Rear Section 23511222, Center Section 23519348 or 23511978)
3 qty Exhaust Manifold Gasket # 23533983
4 qty Mounting Stud # 3818823
12 qty Screw # 8929357
12 qty Spacer # 23511667
What the Market Was Saying
Feedback from customers is encouraged in order to improve our products and to keep abreast of nuances in our different markets. Our goal is to provide solutions to our customers with our parts and services. A recent example of a innovative solution to a market problem dealt with the Detroit Diesel Series 60 exhaust manifold. We learned through customer feedback that the OE manifold was failing frequently. Its design was susceptible to fracture in the middle of the center piece.
Figure 1 - OEM Manifold Indicating Fracture
The Approach
We took on the task of solving the problem. The first steps in the process were to analyze input received from customers and then perform a detailed investigation of the product. Various tests were run to determine the root cause of the failure. It was concluded that a combination of factors was to blame. Temperatures within the manifold can reach 1200 degrees and weaken the metal. The weight of the turbo on top of the manifold coupled with cyclic thermal loading was causing fatigue fractures.
Our knowledge and experience in other engine technologies such as Mack, Volvo, Cummins and Caterpillar was instrumental in finding a solution. Using advanced CAD (Computer-Aided Design) software, our engineering department re-designed the center by adding a rib between the center sections. The extra reinforcement made it more robust and capable of withstanding the extreme operating conditions that exist in real-world applications.
Figure 2 - CAD Illustration of PAIs Design
Dont Just make It Better - Make It the Best
While our re-design of the center pieces fracture location is enough to address the failure, our engineering team found that there were other aspects of the OEM design that could be improved upon. Using cutting edge CAE (Computer-Aided Engineering) and FEA (Finite Element Analysis) software, our engineering team simulated the flow of gas and heat, as well as thermal expansion of the entire manifold system, including the two side pieces. Our analysis concluded that by re-designing the way the three components mate and their internal channels we could reduce turbulence and improve flow. The end result was a design for an exhaust manifold that offers better performance and can stand up to the harsh conditions in the field.
Figure 3 - CAE Rendering of Exhaust Gas Flow
Prototype: From Concept to Reality
The first step toward bringing this design to life was to create a model out of plastic using 3D printing technology. Having a working 3D model allowed us to see details that were not apparent in the CAD model. Several iterations of modifying the CAD model and making 3D prints took place until the manifold design was perfected both virtually and in real space.
Figure 4 - 3D Printed Model
The next step was to manufacture the exhaust manifold. The team researched the qualities of various metal alloys and chose a composite that afforded strength above the extremely high temperatures which would be encountered in usage. This newly redesigned manifold was exhaustively tested on an actual engine in our dynamometer. These real-world results matched our simulations in terms of fit and performance.
The Finished Product
In less than a year, PAIs dedicated team of sales representatives, engineers, and manufacturing technicians identified a problem in the field and created an innovative solution for the market. The newly redesigned exhaust manifold consists of improved side and center sections for enhanced strength, gas flow, and overall performance.
Figure 5 - PAIs Redesigned Detroit Diesel Series 60 Exhaust Manifold
Over time exhaust manifolds warp and develop cracks, leading to exhaust leaks and possibly exhaust fumes migrating into the operators cabin. This is why we manufacture our manifolds out of top quality cast iron. Our exhaust manifolds are designed to flow more efficiently, delivering better engine performance.
Is your brand new exhaust manifold leaking already?!
Don't worry! Small leaks between fresh slip-fit sections is completely normal. This is temporary. Even pre-joined or manifolds sourced directly from OE manufacturers can leak between sections. Gaskets between inner and outer manifold sections are now a thing of the past. They have proven to disintegrate through countless heat cycles during the life of an engine. Manufacturers now rely on exhaust "Soot" to fill small voids, which has proven to provide a permanent seal that you'll never have to worry about.
One of our most reputable exhaust manifold manufacturers states that it generally takes a minimum of 1,000 miles for enough "Soot" from exhaust to build up between the sections to start to provide a nice leak-free barrier. This could take slightly longer if your manifold is:
- Ceramic coated, due to soot having a more difficult time settling on the slipperier surface or
- Exposed to higher than normal Exhaust Gas Temperatures as a result of an higher power engine tune. Higher EGT's do a better job of burning off soot, so it will take longer to create a seal.