Repair And Fix it

An engines induction system can be designed to improve the location of peak torque within its RPM range by altering the intake manifolds plenum volume, runner length and runner diameter. Long and narrow intake runners will result in lower RPM ratings, while short and wide runners will result in higher RPM ratings. Determining the RPM rating at which you want peak torque to occur is up to you, but once you do decide, calculating the intake runner size is straightforward.

Instructions

Calculating Intake Runner Diameter

1

Decide the RPM rating at which you want peak torque to occur. For example, youd like your cars engine to reach 5,000 RPM at peak torque.

2

Multiply the RPM rating from Step 1 by the engines displacement volume and volumetric efficiency. For example, the cars engine has a displacement of 1.5 liters and a volumetric efficiency of 95 percent. Multiplying 5,000 by 1.5 by 0.95 equals 7,125.

3

Divide the result from Step 2 by 3,330. In the example, 7,125 divided by 3,330 equals 2.140.

4

Calculate the square root of the result from Step 3 to determine the intake runners diameter. In the example, the square root of 2.140 is 1.463. The intake runners diameter should be 1.463 inches.

Calculating Intake Runner Length

5

Subtract the result from Step 1, Section 1 from 10,000. In the example, subtracting 5,000 from 10,000 equals 5,000.

6

Divide the result from Step 1 by 1,000. In the example, dividing 5,000 by 1,000 equals 5.

7

Multiply the result from Step 2 by 4.3. In the example, multiplying 5 by 4.3 equals 21.5.

8

Add 17.8 to the result from Step 3 to calculate the intake runner length in centimeters. In the example, adding 17.8 to 21.5 equals 39.3 cm.

9

Multiply the result from Step 4 by 0.3937 to convert the intake runner length to inches. In the example, multiplying 39.3 by 0.3937 equals 15.472. The intake runner should be 15.472 inches long.

Intake gaskets seal gaps between the intake manifold and the cylinder head. They are made in thicknesses ranging from 0.060 inch to 0.120 inch. If too much air gets into the system, the car will not run properly.

Intake Manifold

Gaskets are located throughout the engine, but one of the most important parts of the engine is the intake manifold. The intake manifold regulates the amount of air and fuel your engine gets to create the combustible reactions that power the business. The gaskets can withstand temperatures of 500 degrees Fahrenheit and higher. Some gaskets are made from high-temperature plastic that actually cools the air that passes through them.

Gasket Problem Symptoms

You know that your intake gaskets are no longer doing their job if you start seeing puddles forming under the car when it is in park or when you see a leak in the coolant system. Also, if your engine is rough and slightly jerky, or if you hear whistling from the engine taking in excess air, you have problems with your gaskets.

Repair

A vacuum gauge that checks manifold pressure is used to find the leak. All coolant must be drained from the vehicle and the manifold must be removed in order to replace the gaskets.

Warning

In the book, "Small Black Chevy Engine Buildups," the editors write that with too much air "your engine will turn into melted cheesecake; too little and itll drive like melted cheesecake."

Correct torque value for the bolts on a vehicle is important for auto safety. A torque value that should be paid particular attention to is that of the intake manifold bolts. The intake manifold bolts must have the correct torque value, as well as be torqued in the proper sequence.

Reasoning

The intake manifold is of manufactured of cast iron, and it is bolted to a cast iron block, so proper torque ensures the casting is not damaged. The proper torque also ensures the intake manifold gasket properly seals, preventing debris from entering the combustion chamber. It also prevents vacuum leaks from forming and causing running issues.

How

Proper torque is achieved with a torque wrench. A torque wrench is very similar to a basic ratchet, but it is able to be set to a certain torque value. When the set torque value is achieved, it emits an audible signal, typically a clicking sound, to alert the user.

Amount

Torque is measured in a value known as foot-pounds, sometimes abbreviated "ft-lb." All 12 of the bolts on the intake manifold of a 289 engine require a final torque value of 25 ft-lb.

Process

You cannot simply tighten the bolts in straight sequence, as the last bolts tightened do not seal as well as the first. There is an alternating pattern to assure the best seal. Starting with the front passengers side bolt and moving clockwise, the torque sequence goes 9-5-1-3-7-11-12-8-4-2-6-10 (see reference for image). The sequence must be performed three times to ensure accuracy.

A cold air intake system can offer you additional horsepower and brings cold air into the engine allowing it to run more efficiently. This can add life and fun to your vehicle at a relatively low cost and can be installed in around 90 minutes.

Instructions

1

Write down all the information about your vehicle. This should include make, model, year, engine type, engine size and any custom work that has been done to the engine. This information will help you find the cold air intake filter right for your car.

2

Decide on the cold air intake filter you would like. There are many brands to choose from including K&N, AEM, and S&B. Within each of these brands, there are different air intake systems for each vehicle.

3

Shop around online and locally to find the best price, warranty and installation assistance for the cold air intake filter you desire. Shopping locally can save you shipping costs, as most cold air intake filters are stocked or can be ordered and received within a day.

4

Ask about extended warranty options. While the initial warranty can provide great coverage, an extended warranty can protect your vehicle more and cover maintenance costs.

The intake manifold on old engines provides the entryway of fuel and air into the engine and eventually the combustion chamber, where it turns to energy, powering the engine parts. Identifying this critical channel is fairly easy on old engines, since its connected to the carburetor, which performs the air-fuel mixing prior to going into the engine.

Instructions

1

Park the car in a place that is easy to work in if the car can be moved. Lift the car engine hood and prop it up to stay open on its own. Locate the carburetor assembly on top of the V-8 engine.

2

Use a flashlight to help see the engine parts if you cant see well with the regular room or area light. Locate the exit side of the carburetor where the air-fuel flow will go to the engine. Look opposite the side of the air filter and fuel lines connected to the carburetor.

3

Follow the carburetor to the metal tubular channels that go from the carburetor into the engine casing itself -- this is the intake manifold. Note how the manifold is bolted to the engine case to maintain its connection.

4

Check underneath the engine if the intake manifold is not visible from the top exiting the carburetor unit. Look for a manifold that enters the engine from the side after looping downward vertically from the carburetor.

The 3800 engine is a six-cylinder, 3.8-liter engine manufactured by General Motors. The Series II version of this engine was in production from 1996 to 2005, and appeared in various Buick cars during this period. The 3800 Series II engine contained many changes over the Series I engine, including a new intake manifold that improved the engines breathing. This intake manifold consisted of an upper and lower portion which are composed of cast iron.

Instructions

1

Remove the negative battery cable with a socket wrench to prevent the discharge of fuel. Place a pan under the radiator drain, and open the drain cock. Drain the coolant from the radiator, and store the coolant for later use. Replace the drain cock.

2

Remove the cap on the fuel tank to relieve the pressure in the tank. Wrap a shop rag around the pressure test port on the fuel rail to absorb spilled fuel. Connect a fuel pressure gauge to the test port, and place the bleed hose in a gasoline container. Open the valve on the fuel pressure gauge to relieve the pressure in the fuel system. Remove the shop rag and fuel pressure gauge from the fuel rail.

3

Disconnect the sight shield from the fuel injector with a socket wrench. Remove the air inlet duct and electrical wiring to the spark plugs on the right side of the engine. Disconnect the Manifold Absolute Pressure (MAP) sensor and the vacuum lines from the intake manifold. Detach the electrical connectors from the fuel injectors, and disconnect the fuel lines from the fuel regulator.

4

Detach the fuel rail and Exhaust Gas Recirculation (EGR) heat shield from the intake manifold with a socket wrench. Disconnect the bracket for the throttle cables and remove the throttle cables from the throttle body lever. Remove the upper intake manifold from the engine.

5

Install the new upper intake manifold to the engine, and tighten its mounting bolts to 88 inch-pounds with a torque wrench. Connect the throttle cable bracket and throttle cable to the throttle body lever with a socket wrench. Connect the EGR heat shield and fuel rail to the intake manifold. Tighten the mounting bolts for the fuel rail to 88 inch-pounds. with a torque wrench.

6

Connect the fuel lines to the fuel rail and fuel regulator. Attach the electrical connectors for the fuel injectors, and connect the vacuum lines to the intake manifold. Connect the electrical wiring for the MAP sensor and spark plugs. Connect the sight shield for the fuel injector and the air inlet duct with a socket wrench.

7

Fasten the fuel tank cap, and fill the radiator with coolant. Attach the negative battery cable with a socket wrench and start the engine. Correct any coolant or fuel leaks.