cam shaft suggestions/opinions?

[JeepcoMJ]

my '97 xj 4.0 has a bad cam on the number 6 lobe.

 

I have a '96 used cam in good shape with no scoring/scratching that I could put in.

 

obviously new lifters. I've already got the lifters, head gasket, head bolts, intake/exhaust gasket, push rods, and necessary rockers to replace the bad ones.

 

Would you guys use the used cam, or would you go ahead and buy a new one. and if I'm buying a new one, I certainly am not putting a stock one in it....so what would you suggest? keep in mind i'm trying to increase mileage and power, as much as possible.

 

 

 

 

history on the jeep...I built this motor a year and a half ago, it sat on an engine stand for a year, got installed in the jeep (at the time my old room mate's), and then my room mate moved out with 2 days notice, and didn't do the break-in oil changes. one month later, he beat the piss out of it off-road and blew the head gasket.

I grudgingly did the head gasket for him.

 

3 months after that, he beat the piss out of it again illegally wheeling, got stuck, beat up on it to get out, and drove home with a real bad lifter tick.

 

i told him to stop driving it, not even to start it, until i could look at it. he did not listen. then got drunk on St. Patrick's day, drove it, got it impounded, couldn't afford to get it back, i bought it from the impound lot.

 

 

Thanks

 

Pat

[stamp]

cams are cheap . id buy a new mild one

[jimoshel]

All I've heard from the first day I ever picked up a wrench is to not re use or mix cams and lifters. Wear patterns. If your putting the same lifters back where they originally came from then it's OK. Guess what. I've probably re used and mixed with used lifters over a dozen cams. Never had a problem. What I did was inspect for wear, If any discard. Especially the bottom of the lifters. Make sure they're flat, no wear pattern. Then polish the heck out of them, the cam lobes and the lifters. Polishing removes any wear patterns and makes them as new. I would use the used one. :wrench:

[87Warrior]

Put in a new cam. Use the two used cams as paper weights to keep the shop manuals open.

 

Keep the dynamic compression ratio under 8:1 to stay on pump gas. The DCR takes in account the timing of the valves as well as stroke and bore. Jeep Strokers has a great calculator for this. Keep the DCR in check and don't go with too much lift.

 

I have selected the CompCam 321 for my 4.0 build, not a stroker. It should give me more punch and a stronger power band across the board, with a bulk of the power in the mid range, where a DD needs it. This cam may be too aggressive in a pure stock motor, but should work well with my set up which will be bored and decked.

[JeepcoMJ]

Put in a new cam. Use the two used cams as paper weights to keep the shop manuals open.

 

Keep the dynamic compression ratio under 8:1 to stay on pump gas. The DCR takes in account the timing of the valves as well as stroke and bore. Jeep Strokers has a great calculator for this. Keep the DCR in check and don't go with too much lift.

 

I have selected the CompCam 321 for my 4.0 build, not a stroker. It should give me more punch and a stronger power band across the board, with a bulk of the power in the mid range, where a DD needs it. This cam may be too aggressive in a pure stock motor, but should work well with my set up which will be bored and decked.

 

 

this motor is .030 over. I hardly ever drive over 55, and on the few ocasions that I do, not above 65-70 on the interstate.

 

any suggestions? and prices? I'm having some issues coming across prices for various cams.

 

Thanks

 

-Pat

[comanche12]

what about aggressive cam? gotta love poppy sounds from v8 but wonder what it will sound like from 4.0l :popcorn:

 

just kidding. i agree with above comment about new cams. mildy cam sound good idea too.

[JeepcoMJ]

for the cheapness of it, since my '87/99mj is not done, i'm just putting the motor from that into the xj. much cheaper solution, and it will have me up and running by the weekend.

 

keep this one around then, for a spare.

[kro10000]

All I've heard from the first day I ever picked up a wrench is to not re use or mix cams and lifters. Wear patterns. If your putting the same lifters back where they originally came from then it's OK. Guess what. I've probably re used and mixed with used lifters over a dozen cams. Never had a problem. What I did was inspect for wear, If any discard. Especially the bottom of the lifters. Make sure they're flat, no wear pattern. Then polish the heck out of them, the cam lobes and the lifters. Polishing removes any wear patterns and makes them as new. I would use the used one. :wrench:

 

 

Just nitpicking here, but flat tappets actually have a "crown" in the face, they are not actually flat.