4x4Wire

Jeep - a never ending story: Tires and Wheels

So, today was the big test. After many modifications, the Lil’ Heep was ready for the big test. Or, maybe just another step in the pecking order of modifications.

To set the stage, what started as a basically stock 1994 Jeep Wrangler with over 100,000 miles had undergone numerous operations en-route to its current configuration. Now set with 4.56 gears, front and rear locker, 4 inch spring lift, 2 inch body lift, 4:1 transfer case, NV-4500 transmission, and several other after market modifications, the Lil’ Heep was set to hit the trails.

By: Jeff Yokomura - 2/2001

This project started off like many others. "What if we could raise the engine a inch to gain some clearance and help out driveshaft angles?" Well, as it turned out it was easier said then done. The only one inch lift engine mounts on the market are for 4.0L YJ's and TJ's.

The box said “horsepower guaranteed”.  And, more important, it was CARB approved.  Finally, an air intake system for the pre-1997 Jeep Wrangler that was certified as emissions legal in California.  The air intake kit was K&N Fuel Injection Performance Kit for the 1991-1995 Jeep Wrangler with the 4.0L engine.

Murphy (if anything can go wrong, it will go wrong) and I are old acquaintances. I figured I had an afternoon and a Jeep (Just Enough Extra Parts).  Time to find some more horsepower.

There comes a time in the life of engines when items need to be replaced.  Such a time had come for my Wrangler.  It started with a little vibration under acceleration.  With over 130,000 miles, one motor mount was loose and a small leak had developed with the exhaust manifold.

The motor mount was an easy solution: after market or stock.  Actually, that provoked some discussion.  Turns out, the easy choice is not that easy.  While quality aftermarket products are available, they do come with a price.  In this case, it was about two for one.  In other words, I could get two stock motor mounts for less than the cost of one aftermarket motor mount.

Okay, the vibration was stopped.  New motor mounts in place, it was time to tackle the exhaust header.  The 4.0L engine is prone to exhaust header issues.  And, the exhaust is a critical part of an engine.  You can improve performance of an engine by increasing air flow through the engine.  Basically, the hot exhaust gases need to go somewhere.  Why not through clean bends of an aftermarket performance header?

The stock 4.0L exhaust manifold would not place well in an airflow test.  On the other hand, aftermarket headers are tubular and designed for efficient air flow.  

Take your pick.  There are several vendors providing quality products in a variety of price ranges.  Each has their advocates.  Some advocate for ceramic coating.  All agree on tubular construction.