Jeep 4 0 Intake Manifold Upgrade

4 0 intake and exhaust manifold upgrade post by jeep power july 4th 2008 5 45 pm that is some pure genius with the exhaust.
Jeep 4 0 intake manifold upgrade. Jeep intake manifold swap and evaluation in 1999 jeep had to redesign many parts of the venerable four liter to meet increasingly stringent emission controls. Some of these redesigned parts of the engine were but not limited to smaller exhaust ports to heat the inline catalytic converters quicker the original exhaust outlets were nothing to write home about and now are smaller two inline. The manifold from a 1999 2004 is designed to increase horsepower. This video is how to install a powertech 99 06 4 0l jeep intake on a 98 and prior jeep part 1.
The following is what i found to be true on my 1989 yj. What i did to be able to install a newer horseshoe style intake manifold on a 1996 4 0l engine. Horseshoe manifold should flow better that s why factory installed it on the newer 1999 and up 4 0l. I currently have a 1998 xj with 4 hole injectors 62mm bbk tb cowl cold air intake header along with a new cat and magnaflow exhaust.
If you want to increase the performance of this engine you can make several modifications. Some years may require the newer power. But most ho engines come with a pretty good ignition that will allow 0 045 inch plug gap with no. I love the idea of bolting the exhaust to the bell housing.
Originally the engine was designed by the american motor company but it was later refined by chrysler. While a free flow intake manifold can deliver more. This will work on cherokee grand cherokee and wrangler. I ve been looking into this upgrade and i was wondering if it would be a straight bolt on upgrade with minimal to no modifications to the power steering pump location.
Between 1987 and 2006 jeep used a 4 0 liter inline 6 engine as its standard engine. Jeep 4 0l myth busting true lies. 99 intake manifold upgrade.