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Ford Rangers & Ford Explorers - 4.0L V-6 Tuning Tricks Photo Gallery
Easy Upgrades For Rangers And Explorers
Rex Easley –
May 1, 2004
Photo 1/34 | tuning Tricks ford Explorer | Ford Rangers & Ford Explorers - 4.0L V-6 Tuning Tricks
Photo 2/34 | tuning Tricks ford Explorer | Ford Rangers & Ford Explorers - 4.0L V-6 Tuning Tricks
Photo 3/34 | tuning Tricks valves | 1. After being stranded roadside in the SoCal desert, we pulled the heads and this is what we found: a large crack in the head between the valves that feed the number three cylinder. The more calls we made, the more we learned that these heads were a little on the weak side to begin with and there are almost no good cores to rebuild. It wasn't what we wanted to hear.
Photo 4/34 | tuning Tricks rebuilder | 2a. Luckily, a rebuilder put us in touch with Mahle Motorsports, who is most famous for its pistons, but is now producing brand-new heads for the 4.0L. The heads are 4 pounds heavier than stock, and all that extra cast iron in the right places makes this new casting practically bulletproof. They come ready to build right out of the box.
Photo 5/34 | tuning Tricks stock Heads | 2b.
Photo 6/34 | tuning Tricks motorsports | 3. We brought our new heads out to Boss Motorsports, the in-house team of builders for 4.0-Liter Performance and Central Coast Mustang. 4.0-Liter Performance supplied its stainless valves with tapered stems, as well as valvesprings, seals, and retainers for the build.
Photo 7/34 | tuning Tricks building Heads | 4a. We jumped right in to building the heads. Each valve was dipped in assembly lube and slid into the head.
Photo 8/34 | tuning Tricks assembly Lube | 4b.
Photo 9/34 | tuning Tricks valve Seal | 5. Each valve seal is lubed to slide over each stem.
Photo 10/34 | tuning Tricks closed Valve | 6. While the valve is held closed from behind, the spring and retainer is slid over each stem.
Photo 11/34 | tuning Tricks pneumatic Spring Compressor | 7a. A pneumatic spring compressor is used to hold each spring closed while the keepers are set into place.
Photo 12/34 | tuning Tricks set Keepers | 7b.
Photo 13/34 | tuning Tricks pushrods | 8. The pushrods and rocker shafts were polished up, examined for wear, and set out for assembly. Don't mind the old head bolts that we cleaned up: At the last minute, we learned that they are one-time-use bolts and needed to be replaced. For the record, when a shop manual says to torque head bolts to x lb-ft (sometimes in several steps), then they are regular reusable bolts. If the manual says torque to y lb-ft and then turn 90 degrees, they are non-reusable torque-to-yield bolts.
Photo 14/34 | tuning Tricks jba Headers | 9. JBA Headers had a part number for the 4.0L engine, so we ordered up a set in chrome. The company's kit comes complete with the Y-pipe, gaskets, and all the hardware. We bolted the headers onto the heads before we installed them. We also installed our new Motorcraft plugs at this time.
Photo 15/34 | tuning Tricks carbon | 10. We cleaned the carbon off the tops of the pistons, cleaned up the valley, and washed up the lifters on the short-block. We got the new head gaskets from the local Ford dealership. We set each one in place and checked it before grabbing the head.
Photo 16/34 | tuning Tricks set Heads | 11a. Each head was carefully set in place and checked before dropping the head bolts in.
Photo 17/34 | tuning Tricks checked Heads | 11b.
Photo 18/34 | tuning Tricks torque Head Bolts | 12. To torque the head bolts down, we tightened the bolts from the center out to each end. The first round is to 44 lb-ft; the second is to 59 lb-ft. Then each bolt is turned an additional 80-85 degrees. Those are the numbers Ford gave us with the head gaskets.
Photo 19/34 | tuning Tricks pushrods Dropped | 13. Next, the pushrods were dropped through the heads and into the lifters and the rocker shafts were set on and torqued to spec.
Photo 20/34 | tuning Tricks intake Gaskets | 14. Now the new intake gaskets were set in place and the intake manifold was bolted up.
Photo 21/34 | tuning Tricks por 15 | 15. We used some leftover POR-15 in good old Ford Blue to clean up the stock valve covers and bolted them in place.
Photo 22/34 | tuning Tricks plenum | 16a. Finally, the plenum, throttle body, and everything else we had to unplug or unbolt were returned to their proper place.
Photo 23/34 | tuning Tricks throttle Body | 16b.
Photo 24/34 | tuning Tricks jba Y Pipe | 17. We noticed that the JBA Y-pipe had two bungs welded in the tops of the pipe for a pair of 02 sensors, which are for the later 4.0s. We drilled a hole down by the collector, like our stocker, and welded in a bung we got at the local muffler shop. Then we plugged the two upper holes - Easy fix. The Y-pipe bolted up to the headers and to the stock catalytic converter without a hitch.
Photo 25/34 | tuning Tricks flowmaster Force 2 System | 18. The Flowmaster Force II system is made specifically for two-door Explorers and comes complete with inlet pipe, muffler, tailpipe, hangers, and clamps. Our exhaust was completed in less than 10 minutes.
Photo 26/34 | tuning Tricks airflow Meter | 19a. The mass airflow meter/air intake combo also came from 4.0-Liter Performance. Once we got the old airbox out of the way, it was a simple plug-and-play operation.
Photo 27/34 | tuning Tricks air Intake | 19b.
Photo 28/34 | tuning Tricks meter | 20. The meter simply clamps onto the stock intake tube.
Photo 29/34 | tuning Tricks jba Power Cables | 21. JBA offers its own power cables to complement the headers. As you can see, they're custom-fit for every application.
Photo 30/34 | tuning Tricks plugging In New | 22. Again, it was as simple as pulling off the old and plugging in the new.
Photo 31/34 | tuning Tricks truck Fired Up | 23. How cool does that look? It's as though we're looking at a 1960's Mustang. At this point, the truck was fired up, given the once over, and taken for a testdrive.
Photo 32/34 | tuning Tricks power Module | 24. The last addition we made was this Power Module from Hypertech Inc. It's a chip that rides piggyback on the truck's computer and helps out with both power and mileage.
Photo 33/34 | tuning Tricks computer | 25. Once the computer is loose from the passenger-side kick panel, the module simply plugs into the back and is secured with a set screw.
Photo 34/34 | tuning Tricks test Center | 26. Once we got a few miles on the truck, we brought it back to the test center for another dyno test. We gained a respectable 25 rear-wheel horsepower and nearly 20 lb-ft of torque at the rear wheels. More importantly, acceleration off the line was improved dramatically. Some added benefits are a nice throaty sound from the headers and exhaust, and greatly improved throttle response.