- #1
5.0stang
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Often I see talks about intake taper. This has brought on a few questions from me:)
I am trying to keep this on a Fuel Injection level. The intakes seem to have longer runners that range from 10-15 inches. Compared to carb intakes that are in the 4-6" range. How can they both perform in the same rpm range?
Okay anyways, this is the text I have questions from...
To further help fill the cylinder, it helps to have a high velocity at the back of the valve. To aid in this the intake port can be tapered. To be effective, there should be between 1.7 and 2.5% increase in intake runner area per inch of runner, which represents a 1-1.5° taper. For an example, let’s say you're looking for a 2% increase per inch taper on the 2.02" valve we discussed earlier. We already came up with a port area of 2.56 square inches at just before the valve. Now let’s say the total runner is 10 inches from the valve to the plenum and we're looking for a 2% per inch taper. This turns out to be a total of 3.12 square inches where the port meets the plenum. As you get near the 2.5% per inch taper point, you are pretty much at the limit of helping airflow. A larger taper will only hurt signal strength at the carburetor.
I see that intake taper is talked about in percentages and in degrees.
What is the difference?
On an intake, how can you measure intake taper in percentage or in degrees?
Thanks and I hope I did not make it too confusing to follow.
I am trying to keep this on a Fuel Injection level. The intakes seem to have longer runners that range from 10-15 inches. Compared to carb intakes that are in the 4-6" range. How can they both perform in the same rpm range?
Okay anyways, this is the text I have questions from...
To further help fill the cylinder, it helps to have a high velocity at the back of the valve. To aid in this the intake port can be tapered. To be effective, there should be between 1.7 and 2.5% increase in intake runner area per inch of runner, which represents a 1-1.5° taper. For an example, let’s say you're looking for a 2% increase per inch taper on the 2.02" valve we discussed earlier. We already came up with a port area of 2.56 square inches at just before the valve. Now let’s say the total runner is 10 inches from the valve to the plenum and we're looking for a 2% per inch taper. This turns out to be a total of 3.12 square inches where the port meets the plenum. As you get near the 2.5% per inch taper point, you are pretty much at the limit of helping airflow. A larger taper will only hurt signal strength at the carburetor.
I see that intake taper is talked about in percentages and in degrees.
What is the difference?
On an intake, how can you measure intake taper in percentage or in degrees?
Thanks and I hope I did not make it too confusing to follow.