What Jeep Camshaft Would You Recommend Building Fe Motor
 

I know they say a lower duration and lift cam is best for low end torque and low rpm driving but looking for your thoughts. I also have a link to a website for cams for my motor what cam do you recommend for best best fe!! thanks Just scroll right to see all options

http://www.angelfire.com/my/fan/Jeep4.0Camshafts.htm

Here is stock specs for a 95 jeep cherokee 4.0 242 motor.

adv intake dur 270
adv exhaust dur 270

intake dur at .50 lift 197
exhaust dur at .50 lift 197'

valve lift intake .424
valve lift exhuast .424

Intake Opens @ .050" Lifter Rise (BTDC) deg -21.5
Intake Closes @ .050" Lifter Rise (ABDC) deg 38.5

Exhaust Opens @ .050" Lifter Rise (BBDC) deg 22.5
Exhaust Closes @ .050" Lifter Rise (ATDC) deg -5.5

Valve Overlap deg (advertised) 46
Lobe Separation Angle deg 112
Intake Centerline Angle deg 120

In general terms, about the same lift but less duration is what you are after. It reduces valve overlap, and raises dynamic compression ratio at the same time.

Isky Cams used to offer an off the shelf "Mile-a-more" series of camshafts for RV and towing use (V8 engines) back in the 1970's, they might offer a similar line of cams that cover your engine.

What you really need is an ols world "camshaft guru" like Dema Elgin to take an interest in your project. Guys like Dema have made a living understanding internal combustion engines, while experimenting with thousands of different grinds for various applications over the years. Dema has helped me with custom race cams over the years. He has also worked with road race and NASCAR teams too, yet runs a small 3 man shop and is a down to earth guy that I find easy to work with.

The process might be as simple as you filling out this questionare form and you sendiing in your cam to Dema in Redwood City, CA. Generally, if you are just reducing the lobe duration, they can just put a custom grind on your factory cam (or send in a 'core' from a wrecking yard engine so you can continue to drive your Jeep for now). But I never tell my cam grinder what to do, I tell him what I am trying to do and let him prescribe the remedy. I would also call Web Cam and see if they might be interested in helping you out.

Dema Elgin Cams (650) 364-2187
Web Cam (951) 369-5144

You need to be careful not to make big changes, especially in the intake valve closing point. The fuel injection system may not be able to keep the fuel mixture right if the engine breathes more or less air than the system is calibrated for. This is especially true if you have a MAP sensor instead of an air flow meter to measure engine load.

The original camshaft is not so bad. I like that it doesn't have more duration on the exhaust than the intake and also that it is installed retarded (the intake centerline angle is greater than the lobe separation angle). I'm surprised that it is retarded so much.

If I were going to choose a different camshafts from the chart, I would pick the Jeep 4.2 81-90 camshaft and retard it by 4 degrees with an offset key. This camshaft has a lot less valve overlap than the original, which may help efficiency when the engine operates at low speed and low load.

Just curious, are you running the late model intake manifold? (With the longer, more equal length runners.)
I've heard it was better for fe & torque, but some say no difference at all.

I just found one in a junkyard from a 2000 jeep and it will be installed next weekend.

so should i just leave the stock one those guys didnt have a recommendation

Jeep Intake Manifold
 

I would def. recommend switching over to the newer style (99-01) intake manifold, if you've got one. I was planning this swap for my 89 Cherokee, but ended up trading it off for a Trooper instead.

Be careful, there's a few small things you have to be aware of. You shouldn't have to worry about throttle body differences, as they're both HO motors. Might want to investigate to see if you need the newer-style PS bracket, tho....I know my 89 required it.

PM me if you've got questions, I've got answers to most things XJ related, especially for the older ones.....

yea i already did the new intake manifold which havent gotten through a tank to see if it was any better, if you hit my name you can see the other things ive done.

I've seen the 2000 intake both improve and reduce power/FE for folks. A lot depends on the vehicle and the driver. Just like everything else. The newer style intake will fit the older 87-90 4.0, but the ports are differntly shaped. This usually results in lower perf for folks. The best head for the 4.0 is the 91-95 head (theres a specific casting number but I can't find it at the moment...).

With the parts XJ I have, the motor was going to be stroked (4.2 crank and rods, 4.0 pistons, slightly thicker headgasket makes it a 4.5 liter motor...) and the HO head was going to be used. And then the 2000 intake and a larger throttle body. THat was my thought process, thinking even with performance upgrades, I could maybe get some better FE for my ZJ. Rethinking this. Might modify an exhaust manifold for a small turbo (like off a 2.2 Chrysler form the 80s) to help in low RPMs but bypass for higher speeds. I just want a little extra oomph off the line, or at slow offroad speeds. This is still in the thought process.

Doesn't help with your cam question...

Yea i have the 95 motor so got the good head thats why i did the 2000 intake, as for the throttle body i was told if i do a larger one it will get me worse mpg so i left the stock one. I do have a 3 inch custom warm air intake to the header under the intake and a pacesetter header back exhaust for better fe