Improving performance almost always begins with helping the engine breathe in more fresh air, and get rid of exhaust gases more efficiently. When it comes to helping the engine breathe better, a performance manifold is often the best place to start. A well designed intake manifold does more than just direct gas-charged air to the combustion chamber, it can change how much power an engine makes, and actually remap the power curve.
How does an aftermarket automotive parts company go about designing an intake manifold for the public? We went to Edelbrock, a company that has been designing intake manifolds since 1938, so we could get an inside look on how a manifold goes from concept to car.
A Brief History Of Edelbrock Manifolds
Edelbrock began making intake manifolds when founder Vic Edelbrock Sr. was not happy with the performance that flathead Fords were producing with stock manifolds. Designing what he called the “Slingshot” intake manifold, Edelbrock went on to make racing history by driving his 1932 roadster at speeds of 112 mph at the Muroc Dry Lake in California.
Build what you want to build, the way you want to build it, and make sure it works. – Vic Edelbrock, Sr.
Edelbrock continued to design intake manifolds for special performance applications, including the three-carburetor intake manifold for small-block Chevy engines in 1955. This was followed by the six-carburetor Ram-Log manifold for street and strip use.
In 1958, Edelbrock managed an industry first by getting one horsepower-per-cubic-inch from a 283 cubic-inch small-block Chevy, using their new cross-ram manifold. This breakthrough led Edelbrock to also develop intake manifolds for Pontiac and Chrysler.
The company continued to make high-performance intake manifolds throughout the musclecar era, but remained versatile enough to direct their engineering to meet the special needs of an ever-changing market. When gas prices soared in the 1970s, Edelbrock produced its Streetmaster line of intake manifolds that featured improved mileage, as well as performance.
As new vehicles and engine designs emerge, Edelbrock continues to design new intake manifolds to meet the demands of a public that has become accustomed to their performance-improving manifolds.
Where It All Starts
According to Brent McCarthy, chief engineer at Edelbrock, “Our crew is constantly attending events and shows, and talking to enthusiasts about what their needs are. Sometimes we get leads on new manifold development there,” he stated. “If the car makers release a new engine platform, we are generally pretty quick to begin work on a new performance intake manifold for that application.”
“We have the ability to design a new manifold that is ideal for the situation,” McCarthy explained. “We can tailor the design to a specific application where the OE car makers have to cover a broader range of requirements.”
Once the engineering department has an idea for a new intake manifold application, the team starts by submitting a proposal to management. The management team will ultimately decide if making the part is profitable, and will serve the automotive enthusiast’s needs. “It costs so much to manufacture a new manifold these days. With the computer design, prototyping, testing, tooling, advertising and marketing, the costs can add up quickly,” McCarthy pointed out. “There has to be a real need for the product before we go too far in the development phase.”
There are several considerations that the team can quickly make, based on the type of fuel delivery system used. If the manifold is for a carbureted engine, the engineering team can make a quick decision on whether a single or dual-plane intake is needed, based on their substantial database gathered from decades of testing.
If the manifold is for an EFI application, the engineers must consider if the system is to use a throttle body or throttle plate, and where the injectors are located. “We also have to consider future upgrades that enthusiasts might make, or upgrades that are common with certain applications, like adding forced induction,” added McCarthy.
“There are some quick assumptions we make based on our years of data that also help with a proposal. For EFI systems, runner length can play the most important part,” said McCarthy. “For carbureted systems, the cross-sectional area tends to be the most important part of the design.”
He quickly pointed out that the type of vehicle also plays a key roll in the design. “Issues like hood height need to be factored in,” McCarthy said.
After The Proposal
If the proposal comes back from the management team with a thumbs-up, then the engineering team kicks into high gear, taking the drawings and converting them into actual prototype parts.
“We use a 3D printer that makes a prototype out of plastic material; the runners, baseplate and everything. We build the entire prototype for initial testing. The only problem with plastic, is that it doesn’t hold water, so we can’t use the plastic material on prototypes with water jackets or passages,” said McCarthy.
Before 3D printing, Edelbrock engineers would start with flat drawings of the proposed manifold. The drawings would be used to create prototypes from wood. Various pieces of the part would also be made with fiberglass, and some of the wood would be covered. An aluminum carburetor pad would be secured to the rest of the prototype manifold so that it could be bolted on an engine and tested on the engine dyno.
The newer prototype process is very accurate, and seals quite well compared to previous methods. “We can get about 30 tests from each one of these prototype units,” said McCarthy.
Testing The Parameters
McCarthy explained that the testing process is a matter of running an engine test using the manifold, while measuring all the parameters. It is not just horsepower and torque that are monitored, there are sensors that measure every conceivable measurement that can be read. “We may have to cut the plastic and go inside the plenum or runners. Based on our years of experience and data, we may try some things with the divider wall or add ribs to the floor of the plenum depending on what we are seeing,” said McCarthy. “If one cylinder is running hot because that cylinder is getting more fuel, we may try some things to even fuel and air distribution.”
After the testing and fine-tuning of the prototype is complete, the engineering team begins to assemble a test package to send back to management for approval. This package is not simply the data collected from the tests. It includes a global look at what it will take to manufacture the manifold for the consumer.
Manufacturing takes money, and manufacturing a precision component like an intake manifold is very expensive. You need to consider everything from creating new tooling, fixtures, and even designing new boxes and packaging if the manifold is a different size from any existing manifolds in inventory. All of these factors are included in a package that is sent to upper management for approval.
When the package comes back to the team with the final “Go-ahead” approval from management, the frenzy of activity begins. The machinists begin making the required tooling and fixtures needed to manufacture the manifold, while other members of the team begin working on all the documents that go with each manifold. Any approval processes for federal or state regulations, along with documents like installation instructions are drafted for further approval.
At this time, the marketing team begins to work on packaging and advertising materials for the new product. Everything gets reviewed, as a team from the legal department reviews all the documents and information that have become a necessity in our modern litigious society.
Finally, the crew works on locating gaskets and other parts that need to be included with the manifold. While it may not seem like a big deal on the surface, Edelbrock considers using their own matching gaskets a detail that is essential to the product’s success.
Headed To The Foundry
Edelbrock currently operates two foundries, one is a sand metal-casting foundry that was opened in 1990, and the other facility is a permanent-mold metal-casting foundry, that opened in 2007. These two facilities offer Edelbrock the means to meet all of their aluminum casting needs internally, through their diverse casting processes.
Edelbrock does everything from design engineering to delivering completed manifolds under the Edelbrock roof, right here in the United States. Made in the USA is a big deal to the company, and its Chairman, Vic Edelbrock, Jr.
The newly-cast manifold goes through an entire process of core production, molding, pouring, punch-out and deburring, and cleanup before the final work in manifold production actually takes place. In the manifold production line, each manifold begins the process with a quality control check, and then gets routed to a station where the manifolds are treated with another round of cleaning.
Holes are then drilled into the manifold where mounting points and sensors will be located. Any holes requiring threads are tapped, and the manifold is again cleaned to remove any cutting debris. Once completed, the flat surfaces are planed so the manifold will mount perfectly and not leak.
The manifolds go through a quick heat treating process before they are inspected a final time for quality control, then they are bagged for protection and placed in their boxes along with the gaskets, hardware, instructions, and other documents that Edelbrock supplies.
The manifolds are shipped to different customers and distribution centers around the world, where enthusiasts are eagerly awaiting this bolt-on horsepower. To this day, the company still operates by the founder’s simple instruction: “Build what you want to build, the way you want to build it, and make sure it works.”