Topic: Jeep 4.0

Has anyone used a 4.0 out of a Jeep in Lemons? I have been into rock crawling for some time and I have thrashed many of these engines with no abrupt failure. I have put a balancer on a few and converted a few to open cooling system but that’s it. I had one that spent the two years I owned it gurgling in my pond as I thrashed around in the deep end (They dont float well without doors and a roof). No snorkel, no OIL, no TLC, nothing!!! Just good ole mudslinging rev limit bumping goodness. I have been threatening to do this swap for a while but haven’t seen any discussion on one. You can find them EVERYWHERE in the Cherokees (XJ) for nothing. I can pick up a mid 70’s Datsun truck for $50 with a screwed trans and then dump one of these in for under $200 and have a legitimate Lemons that may skirt inspection due to the shut hood of ancient Z crappiness… Thoughts?

Re: Jeep 4.0

What's the stroke? A short stroke straight six maybe, but can you thrash this thing all day and keep rods in it? Off-idle torque won't win Lemons any more than massive horsepower will...

Jim "Endo" Anderton
30 years of racing and still not Brambilla.....

Re: Jeep 4.0

It has a bore and stroke: 3.88 x 3.44 inches. I have owned multiple Jeeps with the 4.0 as well as many of my friends and I have yet to explode one. In rockcrawling/mud we hold the foot to the floor and hope for the best and the little 6 usually holds strong. They have always been dependable for my crew with very little maintenance. It is not a beasty engine but decent torque and can rev quite well. Here is a link to some info on one and also stroking it.

http://www.fourwheeler.com/techarticles … index.html

Re: Jeep 4.0

Pros: Indestructible

Cons: Attached to Jeeps, weigh approximately two tons

Re: Jeep 4.0

I wouldn't run a jeep. More of a donor for something odd that I can get cheap. I ran across a 2 door amc matador with a 258 today. Supposedly it runs great but who knows. Im trying to determine what my best options would be if presented with the situation of not having a decent motor to start with.

Re: Jeep 4.0

I've had 2 Grand Cherokees. a ZJ and a WJ. Every little niggley thing broke on them accept the damn motor....

Summer's Eve Racing - '09 Yee-Haw; '10 Gator-O-Rama, NorDal Hooptie, Yee-Haw; '11 Gator-O-Rama, NorDal Hooptie (Winner, Class A!)
TARP Racing - '11 Yee-Haw, Heaps; '12 Gator-O-Rama (Winner, Class C ... Looking for a Class B Win to Complete the Trifecta!), Heaps; '13 NorDal Hooptie, Gator-O-Rama

Re: Jeep 4.0

YesIFit wrote:

I've had 2 Grand Cherokees. a ZJ and a WJ. Every little niggley thing broke on them accept the damn motor....

Ha! PREACH! Those things are tough! I watched a guy in a ZJ burn out on a wet rock face for a good 10 minutes going side to side trying to get over and that wound out 4.0 held strong. This thing was stock engine and trans with 42" tires and I believe 4.88 gears. He had been hooning on it all day. The exhaust manifold was almost translucent when he was burning out on the rock face. He got up it once his tires dried the rocks off. I see the turbo motors and race cars do that a lot but the stock 4.0 went total beast mode.

Re: Jeep 4.0

FYI there is an 4.0L XJ coming to the Thunderhill race, should be pretty interesting to see how it does...

Re: Jeep 4.0

Solracer wrote:

FYI there is an 4.0L XJ coming to the Thunderhill race, should be pretty interesting to see how it does...

Awesome! Is there a build thread about it?

Re: Jeep 4.0

there was a cherokee at one of the altamont races, and afaik it didn't do well. anyone that remember it know it it was packing the straight 6?

one idea i had was run that 4.0L in a Z smile

Re: Jeep 4.0

huf_arted wrote:

Awesome! Is there a build thread about it?

There's a thread on the forums discussing it:

http://forums.24hoursoflemons.com/viewtopic.php?id=1247