Increasing Horsepower on a 4.2L Ford F150

by Jason Medina

Install High-Flow Air Filter

Increasing the horsepower on a Ford F 150 4.2 liter V-8 engine can be done easily by making a few simple engine-related modifications. One of the easiest steps to make is to swap the factory-installed air filter in favor of a high-flow, or high-performance, air filter. A high-flow air filter is made to allow more air flow into an engine, a process that increases engine horsepower by increasing engine combustion. K & N, an automotive company that specializes in high-flow air filters, sells a wide variety of high-flow air filters that may be installed on a Ford F 150 4.2 liter V-8 pickup truck.

Install High-Performance Spark Plugs

Basic, factory-installed engine spark plugs are fine for normal, everyday automotive use. However, if increased engine horsepower is desired, switching from factory-installed, or stock, spark plugs to high-performance, or SplitFire spark plugs, which have two spark plug diodes as opposed to one, is a quick and easy way to gain horsepower. High-performance spark plugs do a much better job of igniting an engine's air-fuel mixture, an occurrence that increases engine horsepower and gas mileage simultaneously.

Switch to Synthetic Motor Oil

Synthetic motor oil, which offers increased engine lubricating properties, is a quick and easy way to increase engine horsepower. By increasing engine lubrication (above and beyond what normal, standard-grade oil can do), synthetic motor oil increases engine horsepower by reducing engine friction and allowing engine parts to move more effortlessly. A Ford F150 pickup with a 4.2 liter V-8 engine would gain a significant horsepower boost with the use of synthetic motor oil.

Add a Dual Exhaust System

Most Ford F 150 4.2 liter V-8 pickup trucks come with a factory single-exhaust system. By switching to a dual exhaust system, which uses two exhaust pipes to drain burned exhaust gases from an engine, a Ford F 150 pickup with a 4.2 liter V-8 would realize a significant horsepower boost, between 15 and 25 horsepower. A dual-exhaust system allows burned exhaust gases to exit an engine much more quickly than a single-exhaust system, a process that reduces engine back pressure and frees up additional engine horsepower.

About the Author

This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us.