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want more horsepower

madriver

NAXJA Forum User
2001 cherokee sport 4.0L. I want to rebuild the engine to gain more horsepower and still be a good dd only worked with ford v8's. I need help with choosing the right engine components such as cams lifters pistons ect.
 
I was wondering the same thing. When it comes to 4.0 performance upgrades I am completely blown away at the lack of aftermarket support. I know of a head gasket, 2 over priced sets of roller rockers. And the aforementioned stroker mods. Then there are some home brew turbo/supercharger builds. I have heard mixed results (mostly negative) from comp-cams cams.

If you go into one of the local offroad shops they will tell you how the jeep is the aftermarket king of the offroad world but there is so little motor parts out there. :firedevil where are all the intake/throttle body/cams/heads etc. I know of 1 head but it is about 3X what it should cost. $ for $ its all about a motor swap for power in the jeep. Pretty sad.
 
Well, considering what a cherokee can do and what it was intended for from the factory, the hp and torque is pretty decent. Works just fine for the offroad situations I've found myself in. Streetwise, my old 2wd was pretty peppy on 30's and a 4.10 gearset.

So why would a company that makes after market go-fast accessories fart around with an old tractor motor anyways?
 
Jeep is the king of the after market off road world. There's more than engine in the aftermarket...build a stroker. Plenty of power there.
 
I know of a head gasket, 2 over priced sets of roller rockers.
Oh come one I am sure you could find some more over priced components if you searched a bit longer.
Jeep is the king of the after market off road world.
Sure... that is why there are only 2 companies that work in the Jeep 4.0l. Both of which charge and arm and a leg, one of which couldn't tell its elbow from its butthole.
 
To the OP:

Without building a stroker motor, like you can find here, your best bet is to mill some off the block to increase compression ratio and add a camshaft, cat-back exhaust & a good air intake system. Maybe bore out the throttle body to 60 mm all the way through.

Not a lot else to be done. I mean, you can pick nits and keep reaching, but those are the two basic strategies unless you want to pay the big $$ for forced induction.
 
stroker sounds great but it's mainly a dd i love the numbers they show at jeepstrokers.com (wow i did not know that) but what mpg and driver friendly. it will be in town and on the interstate i want to get the life out of this engine that i know it will produce.
 
Then your best bet is to leave it stock,its a Jeep!
 
Then your best bet is to leave it stock,its a Jeep!

This. You want more HP or to keep mileage? Not getting both.

There are some guys in here that found the perfect combo of stroker, low gears, big tires, and high rpms. I say perfect because they claim to get high teens for mpg figures.

Simply stated, YMMV.

Tapatalky
 
Jeep is the king of the after market off road world. There's more than engine in the aftermarket...

Sure... that is why there are only 2 companies that work in the Jeep 4.0l.

Way to respond to part of a post...You'll find more for suspension, armor, body parts (fenders, etc) and different tops - from the rag top slider for XJs to the various tops for CJ, YJ, TJ, JK than for any other vehicle. Our 4.0 just isn't very well loved by the aftermarket. But if you think about it, in the off-road world, there's not much for engines, period. Sure the Chevy small block has plenty of stuff, but that's largely because of the car world and the fact that the trucks are also used for towing. Same for Ford.
 
The 4.0 doesn't respond well at all to performance upgrades. The non-cross-flow tractor head really inhibits large gains. The dollar per HP is WAY too high.

The best way is to stroke it (increase displacement), or force induct it. Well, or replace it with a V8 that will respond well to mods. :)
 
Oh come one I am sure you could find some more over priced components if you searched a bit longer.

Sure... that is why there are only 2 companies that work in the Jeep 4.0l. Both of which charge and arm and a leg, one of which couldn't tell its elbow from its butthole.



Which two do you know of? I can think of 4 or 5 off of the top of my head.
 
The 4.0 doesn't respond well at all to performance upgrades. The non-cross-flow tractor head really inhibits large gains. The dollar per HP is WAY too high.

The best way is to stroke it (increase displacement), or force induct it. Well, or replace it with a V8 that will respond well to mods. :)

Thats true of some of the 4.0's. You'll find the renix jeeps do VERY well with upgrades. The HO computers tend to work against you.
 
That's one for the renix! exhaust, intake, MSD ignition helped it a bit. Cant wait to regear, waiting for a dana 44 or 8.25 29 spline to fall on my lap first.
 
Thats true of some of the 4.0's. You'll find the renix jeeps do VERY well with upgrades. The HO computers tend to work against you.


You mean it gets them up to HO power? :D


I didn't know that actually. What sort of power are you getting out of headwork and such? I had an 88 for awhile but sold it for my TJ 10 years ago.
 
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