TORQUE CAM SELECTION FOR 4.0 HO

[onehoser]

hello all,

i'm new to this site looking for some input on selecting a cam for my 4.0 ho that would give me more bottom end torque (i'm not concerned with increasing horsepower). here's a bit of background on what i have: freshly bored to 0.020" over, crank journals have been ground 0.10", multi valve angle grind and a rocky ridge header.
i'm not building a stroker at this time, i just want to replace the tired 4.0 ho in my cj7 (93 xj motor) with something with a little more oomph in the low rpms. after going through the archives on this site i've found that the comp cam 68-231-4 and 68-232 might be what i need. my machinist said to be careful in choosing the cam because it might throw off the computer causing it to not run right. can anyone help me out in choosing the right cam?

[SilverXJ]

You will be fine with 68-231-4 cam. It has great bottom end torque. The 68-232-1 is also a good cam, you will lose a little upper RPM power. You may need new valve springs though. I have heard of people running these cams with stock valve springs although the general consensus is that the stock valve springs don't provide enough lift. I suggest you have your stock springs checked for available lift. If you need new springs there are the mopar performance springs and retainers that are a direct drop in. There are also some pontiac springs that will work with minor mods along with some expensive crower (IIRC) beehive springs. I believe the last two are in the FAQ section under misc part numbers.

As far as the computer is concerned, Comp Cam says the 68-231-4 won't work with the computer. Its pure BS. The PCM handles it fine. I believe our PCMs are quite forgiving in this area.

[onehoser]

thanks for the reply silverxj,

does comp cam claim that 68-232-1 is compatible with the pcm? and does it require non stock springs?

[onehoser]

okay, after reading silverxj's post and the cam FAQ i've pretty much decided to go with the comp cam 86-231-4 cam. i still have to figure out if the stock valve springs will or will not work with it. i think this cam will suit me fine for street and mild rock crawling that i do. i'll post up and let you know how it's working out for me. thanks, great site

[Don H Jr]

Onehous: I think you transposed a number on your cam choice.

Don Jr

[onehoser]

Onehous: I think you transposed a number on your cam choice.

Don Jr

68-231-4? this is the one i want.

[amcinstaller]

im sure we all knew what you meant, but yea (the 86 vs a 68, probly just a fast fingers typo). i dont think comp claims that any of the cams are to be used with fuel injection, but lots of people here are using them with no issues, aside from bearings or lobes on a few. but thats the same with almost if not any manufacturer

[Don H Jr]

Comp Cams does bless some of their tiny cams for autos like we run, but folks run the cams they say are stick only and live to brag about the results, some do anyway, lol!
If there was a cam cemetary it would be about full up about now with our leftovers. Too bad the aftermarket cams don't have wider lobes like the original stock cams that came with our 4.0s from the factory; maybe then they'd oil better and have less problems.

Don Jr

[4.whoa]

The main reason they say they don't work with efi is cause the bigger cams can effect vacuum and that can(not will-but can)mess with the comp/sensors. Most of us don't seem to really have issues like that though.

[SilverXJ]

Through all my various engines not once has any cam caused the PCM to throw a fit. Even that Comp cam that had the noses worn off which caused hesitation off idle and near stalling when returning to idle. The PCM didn't think anything of it. I think our PCMs are more tollerant that most.

The 68-232-4 is said by cam cam to be for EFI. The 68-231-4 is said not to be by comp. I just think they are playing it safe as well as the fact that they can't test every scenario. Nor do I think they have really tested them in a EFI 4.0L engine.

[97zjAZ]

So after 5 years any input on how ur cam performed. Did U replace spring or keep the stock? I'm looking to swap in a new cam n would like to keep stock springs. Interested how it worked for you. Thx

[Russ Pottenger]

I've had no issues using stock springs with a 68-232-4 Comp cam.
That being said you'll have to be at or real close to 1.640 to 1.650 installed ht,
because you will be close to .050 from coil bind.

Last bit of advise, Id toss in new replacement springs to be safe.
The Sealed Power number is VS1456. Places like Summit sells them for
$3.00 each

Russ