The idea of blocking off exhaust port on intake manifold has left some people wondering why anybody would do something like that. Well, the answer is that what may not work for you may work for others. Therefore, in this article, you will be learning how to block off exhaust port on intake manifold.
Table of Contents
What is an Intake Manifold?
The intake manifold is an essential part of an engine. It deals with the progression and dispersion of air to the engine’s cylinders. Often, it holds the throttle body where it carries the fuel-air mixture to be moved to the cylinder heads.
Due to aluminum’s ability to be lightweight, it is the most preferred metal used in the casting of the intake manifold. The intake manifold contains a series of tubes that helps in the even distribution of air to all the cylinders
It (intake manifold) sits on top of the combustion engine and it consists of two different parts; plenum and runner
- Plenum: The plenum is the larger of the two parts, it connects all the runners as the other end is connected to the throttle body
- Runner: The runners on the other hand connect the plenum to each of the cylinder heads and it carries the air-fuel mixture coming from the plenum into the cylinders.
There are two types of the intake manifold. They are dual-plane intake manifolds and single-plane intake manifolds.
Functions of Intake Manifold in a Car?
The main duty an intake manifold does is to connect the throttle body to the cylinder heads and also aid the equal supply of air-fuel mixtures to all the cylinders.
A car’s intake manifold takes in air from the outside, traveling through the air filter and through the throttle body that controls airflow speed.
Air then enters the plenum after exiting the throttle body, the air is consequently directed into passageways called runners (the manifolds are tightly fitted to the engine’s cylinder head and the runners are located above the intake valve).
The air is again mixed with fuel from the fuel injectors as it exits the manifold and then swept into the cylinders.
However, if we are being practical, the quantity and quality of the air-fuel mixture supplied to each cylinder are not equal.
Comparably, the intake manifold passages are different in size, angles, contours, flow rate as well as temperature to name a few so there is a noticeable difference in the supply quantity and quality, especially at low engine speeds.
Can You Block Off The Exhaust Port on Intake Manifold?
Yes, you can block off the exhaust port on an intake manifold.
The main reasons why people block off the exhaust port of the intake manifold are to keep heat out of the intake manifold and also to get more power out of their car.
You are wondering how, how does blocking the exhaust port of your intake manifold help get more power from your car?
The exhaust gasses pass through the passage under the intake but due to the high temperature of the gasses, they tend to heat the intake manifold, which in turn warms up the air that passes through the intake manifold making it lose density.
But by blocking the exhaust port on the intake manifold, the heat causing a rise in temperature of the air passing through the intake manifold can be avoided, meaning the air and fuel moving into the cylinders is now denser resulting in more power output.
How to Block Off Exhaust Port on Intake Manifold
One of the ways people block off the exhaust port of their intake manifold is by using a piece of sheet metal between the head and the gasket or gasket and the intake, whichever way. The sheet metal will compress into the gasket and seal it up.
We recommend you take your car to a mechanic to do this work for you to avoid doing it the wrong way.
For those wondering if it is okay and why people block the exhaust port of their intake manifold. Different people have various reasons for wanting to block the exhaust of their intake manifold and justification is made based on their desired output from the car.
Blocking off the intake manifold is not entirely new, there have even been reports of some engines being bought with the exhaust of their intake manifolds blocked.
As to if it is okay to block the exhaust of your intake manifold, it comes down to you and what you want from your car.
Blocking the exhaust has its advantages and disadvantages, so it all plays down to why you want to block the exhausts and if it is worth it to you, putting into careful consideration, the benefits and shortcomings.
Pros of Blocking Off Exhaust Port on Intake Manifold
Blocking off the intake manifold allows for an increase in the power output of your car engine. The intake manifold is situated above the passage through which the hot exhaust gasses travel, which results in a significant increase in the temperature of the air passing through the intake manifold, allowing it to lose density.
So by blocking off the exhaust port, you cut out the heat supply making the air and fuel moving through the intake manifold denser and an increase in power output is achieved.
Also, provides insurance against vapor lock in the summer.
Dangers of Blocking Off Exhaust Port on Intake Manifold
The dangers of blocking off the exhaust port on the intake manifold are:
1. You Can’t Run an Automatic Choke
To run an automatic choke, heat is needed promptly to make the choke come off, but by blocking the exhaust port of your intake manifold; you won’t have enough heat quick enough to make the choke come off.
2. The Vehicle Takes More Time to Warm Up
Due to the blocking off of the exhaust port and the subsequent reduction of heat passing through the intake manifold, heat circulation is reduced and engines take more time to heat up since blocking the exhaust makes the manifold run cooler.
3. There is a Risk of the Carburetor Icing Up
Blocking off the exhaust port helps you run your car at a lower temperature making it cooler. This might not be a problem under hot weather but is most likely to be a big issue in cold weather.
In this circumstance, it is best to have a heat riser. The heat risers were created to help during the cold weather, the heat helps vaporize the fuel when intake is cold.
4. Zero Exhaust Tuning Benefits
When you block off the exhaust of the intake manifold, you also prevent the exhaust from performing the functions for which it was put in place.
Final Thoughts
While in a haste to block off the exhaust port on the intake manifold, ensure you do it the right way. We recommend you meet a professional mechanic to help you with the work.