Camshaft headache.

[xj bmx]

» Today, 2:09 pm
So i purchased a spair motor to atempt a stroker, but decided against it as a first rebuild and to save the stroker for the engine thats in the jeep now.

Since it did not come with a camshaft, i need to buy one and figured why not get something to possibility add some power. Ive seen people arguing about adding "performance" cams saying things from, "they are the only real way to get real gains out of a mostly stock 4.0" to "the stock cam is the best made" or "an aftermaket cam will little to nothing for performance" along with stories of aftermarket cams snaping in half.

Now, this motor will be going into my 92 cherokee with an aw4 trans that is my toy (off road toy of course) so low end is where I would like the gain. Im not expecting it to make me shit my pants in a fit of joy when i smash the gas but knowing its giving me a little more would be nice.

I have my eye on the xtreem 4x4 cam from comp that jp magazine put in one of there motors.

So wich to choose?

 

[Talyn]

Comp Cam 68-231-4 or one of lunati's.

 

[Dr. Dyno]

» Today, 2:09 pm
So i purchased a spair motor to atempt a stroker, but decided against it as a first rebuild and to save the stroker for the engine thats in the jeep now.

Since it did not come with a camshaft, i need to buy one and figured why not get something to possibility add some power.

I suggest you rebuild the spare engine into a stroker, add the cam of your choice (the CompCams 68-231-4 is a very good one), and swap it into your Jeep when it's finished. Then you can either keep your existing 4.0 as a spare or sell it to recoup some of the stroker build-up cost.
I think it's a waste of time and money swapping an aftermarket cam into a stock 4.0 'cause the performance gain isn't enough to make the effort worthwhile.

 

[h-townxj]

I agree with the lunati I've chosen the 63501 due to it's high lift and no overlap. But then again I'm building a compleatly different motor than most people. We've had good luck with lunati in other motors though

 

[XJRunner]

I run this one and can really notice it going up hills
http://www.summitracing.com/parts/CCA-CL68-232-4/Application/?prefilter=1

 

[Talyn]

I agree with the lunati I've chosen the 63501 due to it's high lift and no overlap.

Using seat-to-seat timing it has 35* of overlap. Using .050" it doesn't have any, but nor do most of the 4.0L cams. The exceptions I know of are 505's Stage 3 and a Engle custom I have seen.

 

[badron]

FOR THE STROKER!
Your stroker will love to make compression. So you will need to watch your compression ratio. With the XJ timing being nonadjustable or very pricey to mod to make it so. You want to keep that CR down (somewhat). Else you could end up needing racing gas to run it.
I personally know 2 strokers that run cams with a little more over lap then stock in order to kill off some compression. Both still need hi-test but have no ping. The right cam can still make gobs of bottom end (no ping) but the over lap will help move that torque curve up the RPM range a bit.
You CAN mod the timing to control ping or there are other ways to control CR but the cam looks like a win win thing to me.
Some others have also gone the cam rout and will ring in with hard numbers. PLEASE

 

[fsjfan]

The Comp cams extreme energy cam has worked awesome for me in several different 4.0 builds. The Sumit Racing site lists it as not not OBD2 compatibale but the Comp cams site says it is and I have found it to work very well with both the stock ECM and especially well with the addition of a Jet stage 2 module. Remember though that a cam can only move as much air as the intake and exhaust allow. I think that's why you hear some guys grumble about not noticing a big HP increase. Stock cam or aftermarket, the 4.0 really wakes up with a 62MM throttle body and 2.5" performance CAT, pipe and muffler.