So Fix it

Catalytic converters, also called "cats," absorb exhaust heat, and should, ideally, be as close as possible to the exhaust manifold for emissions compliance. This placement varies by make and model and can have a significant impact on performance.

The Y-Pipe

V-type engines often use y-shaped pieces of tubing to join the cylinder banks exhaust streams before entering into the converter. Converters are often bolted right to the back of this Y-pipe.

Direct Connection

Many manufacturers, such as Honda and Toyota, are becoming known for bolting the catalytic converters right to the exhaust manifold outlet, with nothing in between.

Down Tubes

Most turbocharged engines use a down tube, which is a smooth piece of tubing that allows a turbos exhaust flow to move away smoothly, before encountering the restrictive cat.

Oxygen Sensor

All new vehicles have an oxygen (O2) sensor somewhere between the exhaust manifold and cat. This works in conjunction with an after-cat O2 sensor to notify the engine control computer of any converter malfunction.

Exhaust Brakes

Large diesel trucks often have a large valve in between the cat and manifold, known as an exhaust or "Jacobs" brake. When closed, these valves create back pressure in the engine and allow a driver to control downhill acceleration without using the foot brake.

Roller chains are most commonly used on bicycles, automobile engines and heavy machinery for the transmission of power. They come in a variety of sizes to meet almost any application. The larger the size of chain, the larger the roller diameter, pitch and tensile strength the chain is rated for. Choosing the right chain for your application is important for safety and functionality.

Roller Chain Terms

The chains pitch is the distance between the center of the neighboring rollers; its diameter is the width between the link side plates. The digit furthest to the right in the chains number denotes its type: 0 for a normal chain, 1 means a lightweight chain and 5 for a rollerless bushing chain. If the chain number ends with an "H" it is a heavyweight chain.

35 Chain

The 35 chain is a rollerless type chain. It has a pitch of 0.375 inches and diameter of 0.2 inches. It is rated for a tensile strength of 1,758 pounds and a working load of 480 pounds.

40 Chain

The 40 chain is a normal, roller-type chain. It has a pitch of 0.5 inches and a diameter of 0.312 inches. It is rated for a tensile strength of 3,125 pounds and a working load of 810 pounds.

Differences

The main difference between the 35 and the 40 chain is that one is rollerless and the other has rollers. The two chains also have different pitches and diameters, which will limit their interoperability. Additionally, the 40 chain is rated for a significantly higher tensile strength and working load than the 35.