1. We started by removing...
1. We started by removing all the parts and instructions from the box to make sure everything was there and each piece was properly identified.
The ability to pass large quantities of air through an engine is one primary factor to creating torque and thus power to the rear wheels. It has been well established on the dyno, the dry lakes, and the racetrack that reducing back pressure to improve airflow is a significant factor to improving engine performance. This basic reasoning is behind the development of Tubular Exhaust Systems (TES) at the Edelbrock Corporation, where improving airflow through an engine began in the early days with intake manifolds at the very beginning of the company's history.
The Tubular Exhaust Systems come with several finishes: the basic package is painted to prevent surface rust before installation, the ceramic-coated headers are the next step up for protection and longevity, and the nickel and chromium plate finish is the brightest. Most TES headers are available with a ceramic coating. Ceramic coatings are chemically bonded to the steel on the exterior, which provides the ultimate protection against corrosion and erosion. Some TESs are available in 409 stainless steel for extra durability against the high-heat conditions found in heavy-duty use, such as when towing and hauling heavy loads. Edelbrock's stainless steel headers have a five-year warranty against rust, corrosion, or burn-through.
2. Our early '80s Chevy truck...
2. Our early '80s Chevy truck was relatively stock under the hood and needed to be able to pass California emissions testing for the foreseeable future. We recently installed a late-'80s Chevy electronic fuel injection that helped lower the exhaust system pollutants, but the EFI did less for performance than we had hoped.
Most importantly, the California Air Resources Board has approved all Edelbrock TESs for street use on pollution-controlled vehicles in all 50 states (Executive Orders D-215-52, D-215-53, and D-215-56). If installed properly, these headers are designed to improve the exhaust efficiency of the engine they're being installed on. A performance gain can also be expected by the installation of a TES.
Our early '80s Chevy truck with a 350ci Chevy engine has been upgraded from a carbureted intake to an early '90s throttle body EFI (CCT Feb. '03 "Turbo City Leads The Way"). However, we believed the engine's performance wasn't anywhere near its potential because it was still struggling to breathe, especially when towing. Knowing the greatest performance gain per dollar on any internal combustion engine is improved exhaust flow, we felt the addition of an Edelbrock TES was a solid decision for improved performance.
Since this Chevrolet truck will continue to be inspected every other year, the Edelbrock TES makes a perfect solution to our needs. If you wish to add a CARB-approved Edelbrock TES, check out how easy the installation can be, then get a set of your own and experience the difference for yourself. The following photos show each step and how you too can improve the performance of your custom classic truck. CCT
3. For safety's sake, we began...
3. For safety's sake, we began by disconnecting the negative battery cable. The original cast exhaust manifold was still in place and the stock air-injection reactor tubes were also in place. As you can see, the spark plug wires stuck straight out from the plug. The plug wires had to be modified with an L-type head to work with the new exhaust manifold, but we'll write more about that later in our story.
4. With the truck up on a...
4. With the truck up on a lift, Karl began to disassemble the original exhaust at the point where the crossover tube connected to the exhaust manifolds. To prevent stripping and breaking the original hardware, a little penetrating oil was an excellent idea to help loosen bolts that were rusty.
5. The original crossover...
5. The original crossover tube was clearly visible under the transmission pan, passing next to the oil filter on the driver side of the engine.
6. Looking behind the crossover...
6. Looking behind the crossover tube, we see the catalytic converter and the original muffler.
7. While waiting for the original...
7. While waiting for the original exhaust manifolds to cool down a little more, we started to cut the catalytic converter behind the unit. We planned to replace this small one with a new one with larger-diameter tubes in and out to help improve airflow.
8. Karl had all the nuts and...
8. Karl had all the nuts and bolts holding the crossover tube out of the flanges and the back end of the exhaust tube cut away from the part of the exhaust system that would be replaced later. We set the crossover tube aside, but kept it handy to identify how the new Edelbrock two-piece crossover tube would replace this hunk of exhaust.
9. Notice the new crossover...
9. Notice the new crossover tube doesn't look exactly like the original unit. The Edelbrock crossover tube has two pieces including one that slides inside the other.
10. We returned the truck...
10. We returned the truck back down to the ground and grabbed a fender cover. To save time and insure the spark plug wires would be easy to identify, Karl numbered each plug wire head with a paint pen. We also removed the air cleaner system, taking note of line and hose positions.
11. The air-injection reactor...
11. The air-injection reactor tube was disconnected from the original exhaust manifold on both sides as well.
12. The air-conditioning rear...
12. The air-conditioning rear support-bracket bolts will need to be removed on some models. We continued by removing the bolts that hold the power steering pump in place. Then, we removed one bolt from the front of the engine block and one bolt at the forward end of the exhaust manifold.
13. The driver-side manifold...
13. The driver-side manifold was removed. Notice the oxygen sensor was in place. We carefully removed it to use on the new tubular exhaust manifold.
14. Here are the two old exhaust...
14. Here are the two old exhaust manifolds on the ground with the air-injection reactors still connected. We needed several pieces from the plumbing to connect the new tubular headers.
15. A comparison of the original...
15. A comparison of the original cast exhaust manifold and the new tubular header revealed some variation in design. This variation made the longer tubular exhaust header easier to manufacture and perform more efficiently.
16. To prevent breaking any...
16. To prevent breaking any spark plugs, we removed them before beginning to install the tubular exhaust headers.
17. It's easy to identify...
17. It's easy to identify which side is which. The passenger-side header was put in place first. We'll connect the A.I.R. check valves later.