99+ cam

[CandyCaneXj]

They are both worn like that all the way around. So should be cam walk? funny the one has 177000 miles on it and one has 115000 miles and both cams and lifters look the same on flat surfaces. And both springs are the same free length. The timing cover button on the higher milage one looks twice as worn as the other.

[jeepxj3]

So what cam did you decide on?
210/220* duration is a big cam. Will if not have enough vacuum for the ecu to control?
You have to be concerned with how big a cam you go depending on how you are going to tune it.
Maybe something closer to the 231 cam which has 206/214*, maybe a 204/208* or 204/210*.
I think that the 210/220* cam will need a custom tune to run well.

[biscuit]

i have been swamped at work. so everything went on pause for a couple months.

i am at cam decision point. a guy on the forum has this to get rid of.

Cam# Jeep4L, H64307-66299-112 (this is a jones cam)
202/208 @ .050"
.307"/.299" Lobe Lift
.491"/.478" Valve Lift w/1.6 rockers
112 LSA
109 ICL

the CR calculator does advertised not @.050 so i am having a hard time wrapping my head around the jones
cams and how they will affect my build. i am thinking about using the cam profile that russ suggests, but having jones grind it.

i have a silly question?? regarding the splash hole on connecting rod bearings being eliminated.... if i am using 4.2 rods, is there a way to utilize this "older" squirting design??

[Russ Pottenger]

Dave,

Maybe I'm not understanding your connecting rod oil squirter problem.
Your 258 rods should have the oil squirter's in them.
All that has to be done is to put a corresponding notch in the bearing.

Another consideration concerning your camshaft choice.
I like the idea of the thrust plate, but the problem is there's not a good double roller timing set available for them as far as I know.

You know my opinions on the wide load cams. I know a lot of respected people on this form disagree with me.
To be clear I'm not saying that there's anything wrong with a wide lobe, but that it's not necessary.
The reason is the lobe is ground with a taper in it. With the lobe offset in the lifter bore and the corresponding lifter having a crown on it, the lifter never rides on the center of the camshaft lobe. If it did it would go flat immediately.

The best way to ensure a camshaft from going flat.
1. Proper valve spring pressures
2. A good Molly lubricant on both the camshaft and bottom of the lifters.
3. Not totally necessary but a great idea is to nitrite the camshaft.
4. Last but not least is the proper break-in procedure. In the initial fire up you should make sure the engine runs at about
at about 2500 RPM's for around 15 mins. If you're not using a break in oil, make sure at least you put in a good ZZDP
Additive.

I welcome anyone's thoughts or ideas

Russ

[Cheromaniac]

I think you've already hit the nail on the head Russ.
I don't have anything to add.

[jsawduste]

X 2 on what Russ mentions.

See that Jones is recommending 6* more exhaust duration but at a lower lift. Be curious to plot those number out with head flow but would need more information to make it worthwhile..

Mid 220`s @ .050 with 112*+ LSA keeps the MAP sensor happy even with a factory ECM. That said the tuning guys can cal the MAP sensor for a lower vacuum signal if need be. Gears and exhaust play a big factor in how a cam with that much duration works for drivability. Properly set up those 220* cams will still pull down to sub 700 rpm and still torque up pretty hard.

IMHO with proper ECM calibration I think we could be running a lot more cam then what is typically run.

[jeepxj3]

i am at cam decision point. a guy on the forum has this to get rid of.

Cam# Jeep4L, H64307-66299-112 (this is a jones cam)
202/208 @ .050"
.307"/.299" Lobe Lift
.491"/.478" Valve Lift w/1.6 rockers
112 LSA
109 ICL

the CR calculator does advertised not @.050 so i am having a hard time wrapping my head around the jones
cams and how they will affect my build. i am thinking about using the cam profile that russ suggests, but having jones grind it.

I think I read somewhere that the Jones can 202/208 @ 0.050" is 260/264, if that helps.

[Cheromaniac]

I think I read somewhere that the Jones can 202/208 @ 0.050" is 260/264, if that helps.

You're close but the advertised duration of that Jones cam is actually 256* intake / 264* exhaust, so you can use those numbers for the DCR calculator.

[CandyCaneXj]

I just wanted to update this by apologizing to Silverxj! Reading previous comments from awhile ago I was not accurate with some info I gave and he corrected me and I never acknowledge it so thank you Silverxj for being a good sport. I was wrong. You were right.

[SilverXJ]

No problem. There is a bunch of misinformation floating around as well as learning. I did not think to post this image when we were discussion the lifter contact patch. However, this is a narrow lobe cam by Isky with machinist dye on it, then installed in the engine and rotated by hand . I think it shows in good detail the path.

[I6FAN]

Is that contact patch towards the front of the cam, or towards the rear? I'm thinking it's the rear. That way the cam is "supposed" to have force pushing backwards. The reason I ask is because I've heard of different configurations (not for Jeep) where the front half of cam-lobes are to the front and the back half of the cam-lobes are to the rear; neutral thrust condition. Hopefully, all the aftermarket cams follow original Jeep blueprints!!!

[SilverXJ]

Thats to the rear of the lobe.

[dwg86]

As far as cam choice, I ran a 214/214 @ .050 and 501/501 valve lift 112 lobe centers installed 108. I didn't have any computer problems in my 2003 Wrangler. There are plenty of more experienced and knowledgeable out there on cams, but from what I have read and even talking to bullet cams on grinding a cam for my 401 last month, split lift/duration cams with a longer duration on the exhaust kills torque. The longer exhaust duration is for helping on scavenging exhaust gasses, which is a good thing. It also has to do with head and exhaust flow, so I know you just can't through a blanket statement saying that a split lift/duration is a bad cam choice. To me it's like walking a fine line. Where is the line between exhaust scavenging and killing to much torque? I would talk to someone about a specific cam for the Jeep inline 6. To many cams are just a copy from a SBC cam grind. It seams to me that a cam with a 10 degree split on intake/exhaust duration is a lot, but do you own research and homework. You will get A LOT of opinions on cam choices. Listen to those who are in the business on building engines, and have the experience with seeing what happens with different cam choices. I don't know Russ, but he is an experienced engine builder, and I like what he has to add to our forum. silverxj, cheromaniac and jsawduste are always a voice of experience and reason. And flyinryan has a great reputation for ECU tunning.