Cam question for a Jeep

[94 formula]

For anyone whos knows much about Jeeps especially the 4.0L Powertech inline 6cyl, I'm planning on building a stroker soon for my Jeep Wrangler and would like some suggestions. I helped my brother build one for his cherokee a while ago its relatively easy to do he just had the block bored .040 and then bought the rods and crank for a 258 inline 6 and put in a comp cams extreme off road cam (I think thats the name) I forget the numbers on it but its set up for extreme bottom end. The Jeep is perfectly setup for what he wants, it has 3.55 gears 5spd (ax15) and 30in tires. He can pull his boat up any mountain without down shifting the only down fall is that at 3,500 rpms it falls flat on its face. I need to build something that'll pull to a higher rpm but still has great low end. I have 35in tires 4.11 gearing and 4:1 gears in my transfer case. I decided to stick with 4.11 gears because it sees plenty of highway use but put 4:1 gears in the transfercase so it can crawl off road. With the 4:1 ratio I need an engine that'll rev out decently because sometimes in mud or loose rocks the best thing to do is just spin your way out and since you are only crawling along usually in 1st or 2nd gear if you shift you loose too much momentum and get stuck. Can anyone make a recomendation on a cam that'll make great low end torque but still pull atleast decently to 5,000 rpms?

[Jeff_in_Atl]

For anyone whos knows much about Jeeps especially the 4.0L Powertech inline 6cyl, I'm planning on building a stroker soon for my Jeep Wrangler and would like some suggestions. I helped my brother build one for his cherokee a while ago its relatively easy to do he just had the block bored .040 and then bought the rods and crank for a 258 inline 6 and put in a comp cams extreme off road cam (I think thats the name) I forget the numbers on it but its set up for extreme bottom end. The Jeep is perfectly setup for what he wants, it has 3.55 gears 5spd (ax15) and 30in tires. He can pull his boat up any mountain without down shifting the only down fall is that at 3,500 rpms it falls flat on its face. I need to build something that'll pull to a higher rpm but still has great low end. I have 35in tires 4.11 gearing and 4:1 gears in my transfer case. I decided to stick with 4.11 gears because it sees plenty of highway use but put 4:1 gears in the transfercase so it can crawl off road. With the 4:1 ratio I need an engine that'll rev out decently because sometimes in mud or loose rocks the best thing to do is just spin your way out and since you are only crawling along usually in 1st or 2nd gear if you shift you loose too much momentum and get stuck. Can anyone make a recomendation on a cam that'll make great low end torque but still pull atleast decently to 5,000 rpms?

The problem isn't going up a hill. It's goind down. A 2000 pound boat can be pretty scary with it pushing a little Wrangler around. The short wheel base makes is unstable when towing.

[94 formula]

The problem isn't going up a hill. It's goind down. A 2000 pound boat can be pretty scary with it pushing a little Wrangler around. The short wheel base makes is unstable when towing.

I'm not talking about pulling a boat with my Wrangler.

I helped my brother build one for his cherokee

My brother pulls his boat with his cherokee. My Wrangler doesn't even have a hitch on it 8 inches of lift and 35's probably wouldn't work out to well as a tow rig .

[Jeff_in_Atl]

I'm not talking about pulling a boat with my Wrangler. My brother pulls his boat with his cherokee. My Wrangler doesn't even have a hitch on it 8 inches of lift and 35's probably wouldn't work out to well as a tow rig .

OK. Yea that wouldn't be a good idea. LOL

[fastTa]

I'm not all that familiar with that particular 4.0 liter Jeep motor, but I am fairly knowledgeable when it comes to engine building and camshaft design.

Generally speaking if you are searching for something that makes decent low end torque yet still retains good power up top, you will proabably be interested in purchasing a cam that has some ground in advance and a numerically lower than normal LSA(Lobe Separation Angle). Generally speaking, the tighter(lower) the exhaust lobe centerline and the intake lobe centerline, the more your motor will be able to take advantage of the increased potential for overlap scavenging at higher RPM's.

The ground in advance will effectively give you a sooner (lower crank angle) IVC(Intake Valve Closing) point and will help to build cylinder pressure by effectively increasing your dynamiuc stroke. The more cylinder pressure the more torque you will make.

As far as picking the overall duration and lift of the camshaft, that will all depend on your cylinder heads and intake setup. You will obviously want more lift and duration to make more power across the board, but choosing the actual duration and lift, and whether it is single pattern, split pattern, or reverse pattern and the balance between the lift and duration will depend largely on your heads, intake, and gearing.