Cam suggestions

[tcervinsky]

I'm in need of a suggestion for a replacement cam. I am having my motor freshened up and I'm going to replace the cam. Block is a '95 and I'm installing it into a '97, my understanding is that the later blocks have a dual patteren cam to improve torque (and I would guess to improve emmisions), so I'm thinking I should at least go with a dual patteren cam. Since I'm already into the expense of replacing this I'm hoping someone can suggest a "better" cam- possibly increasing HP/TQ and dare I say ... gas mileage? So what I'm saying is that I don't want to go crazy with HP- this will be a DD but may see a 2" lift and slightly oversized tires someday after my stock tires wear out.

I've tried calling Comp Cams once- seems they have just one cam that will work. I've been reading up on all these different cam specs (and have seen several variations of stock cam specs) and I just can't make good sense of it all.

Again, vehicle is a '97 with an AW4 and a 242TC, 8.25 rear with stock 3.55 gears. The vehicle will pull duty as a DD and will see plenty of highway miles. There will also be occasions when I will pull a very small utility trailer and maybe someday a pop-up. No extream rock crawling or mud bogging- just simple dirt trails and maybe a trip to RC someday after the lift.

Thanks for any help you can give me, sorry for the long post.

 

[Talyn]

The PCM is pretty forgiving and their "not for fuel injection" is just a blanket statement. The popular one is their 68-231-4. However there are many more companies. I had an Isky custom that I liked in my stroker. I recommend calling a few companies and asking for a recommendation based on your needs/wants. Isky, Lunati, Clay Smith, Erson, Engle, Crower, etc.

 

[BlueCuda]

Crane is back in business but I don't know if they make cams for the 4.0 again yet. I have a crane 75390 in my stroker and like it. I would like to a little bigger with it one day but doubt I ever will.

 

[tcervinsky]

Here's the problem... I'm not building a stroker. There's too much unreliable and misunderstood information about how to build a stroker with predictable results- it's a real hit or miss and there are no professional Jeep storker builders, just a lot of people who think they are.

I'm in this to build a reliable motor with MAYBE a slight power increase. This jeep is probably never going to see anything larger than a 30" tire and will most likely spend most of it's life on the highway. I'm not going rock climbing or racing mustangs in the quarter mile, just driving it and wanting the best performance I can get for the least amount of money. So no custom ground cams and you're not going to talk me into the expense of a stroker.

So far my happy medium looks like a Comp Cam SK68-232-4. Close match to the stock dual patteren cam with a slight increase in lobe lift. Probably make some changes to the intake and exhaust to allow it to breath a little better and that's about it. Budget is not over $1000.

 

[Dr. Dyno]

So far my happy medium looks like a Comp Cam SK68-232-4. Close match to the stock dual patteren cam with a slight increase in lobe lift. Probably make some changes to the intake and exhaust to allow it to breath a little better and that's about it. Budget is not over $1000.

If you go for either the CompCams 68-232-4 cam or the 68-231-4 (wider powerband than 232), you'll need to upgrade the valve springs/retainers/locks and these are going to eat into your budget. If you're going to the trouble of swapping the cam, I suggest you DIY port the head to make good use of the extra lift/duration of the cam. You could also swap in a '99+ intake manifold to restore some of the low rev torque that'll be lost with the cam swap and broaden the torque curve.

 

[BlueCuda]

Here's the problem... I'm not building a stroker. There's too much unreliable and misunderstood information about how to build a stroker with predictable results- it's a real hit or miss and there are no professional Jeep storker builders, just a lot of people who think they are.

I'm in this to build a reliable motor with MAYBE a slight power increase. This jeep is probably never going to see anything larger than a 30" tire and will most likely spend most of it's life on the highway. I'm not going rock climbing or racing mustangs in the quarter mile, just driving it and wanting the best performance I can get for the least amount of money. So no custom ground cams and you're not going to talk me into the expense of a stroker.

So far my happy medium looks like a Comp Cam SK68-232-4. Close match to the stock dual patteren cam with a slight increase in lobe lift. Probably make some changes to the intake and exhaust to allow it to breath a little better and that's about it. Budget is not over $1000.

There is plenty of reliable info on building strokers, if you can build a stock 4.0 you could build a stroker no problem. The problem is there is alot of information out there and you have to choose a source and stick with it. If you go to every stroker sight you will find so much stuff you will always be second guessing it.

I built my stroker off the recipe on bc4x4.com 8 years ago.

 

[tcervinsky]

If you go for either the CompCams 68-232-4 cam or the 68-231-4 (wider powerband than 232), you'll need to upgrade the valve springs/retainers/locks and these are going to eat into your budget. If you're going to the trouble of swapping the cam, I suggest you DIY port the head to make good use of the extra lift/duration of the cam. You could also swap in a '99+ intake manifold to restore some of the low rev torque that'll be lost with the cam swap and broaden the torque curve.

I'd be surprised that I'd need new springs with such a small increase over stock lift (stock= .408, CompCam = .462). I would also think that if I required new springs they would have included them with the kit (I searched and didn't see this cam in a kit with new springs anywhere). I'll talk with my builder tomorrow and see what he has to say. Thanks for the input.

Thanks for the info on the stroker, but I dont' think it's a direction I need to go. I've also heard that the stroker isn't too freindly on the MPG either.

 

[Talyn]

The Comp Cam springs won't work on the 4.0L head. The cam is .460'' Intake / .476'' Exhaust.

 

[tcervinsky]

So Comp Cam springs wont work and stock springs wont work then wth?

Guess this motor just wasn't ment to be improved- Stock cam it is then I suppose.

Oh, and I thought I mentioned, I'll be using the 7120 head ( and the lobe lift for the pre-96 is .424, so the difference is even smaller). What is it about the spring that won't work?

 

[seanyb505]

IIRC they are only rated for .430 lift. Cam companies may try to tell you otherwise. Crane (before they restructured) tried to tell me that the make THE factory springs and the springs were rated for .450" of lift.

 

[gradon]

The stock replacement springs are mopar p4529214(87 and below) and p4529215(88+) both rated up to .430" lift. In the mopar cam charts, for the P4529228ab cam, .430 lift in/ex, and the P4529229ab cam, .440" lift in/ex, mopar recommends the use of the p4529214 springs(that are not "rated" for .440" lifts); for the p4529230ab cam, .450" lift in/ex, mopar recommends the use of the p5249464 springs, good for lifts up to .525". I've been running the latter combo for a few years and 30+K now. I advise people to choose the p5249464s when using cams with lifts .450"-.525". They're drop-in, thus don't require the seats to be worked on, just the matching p4452032 retainers and locks that match your valves(single- or triple-groove lock).

 

[gradon]

double

 

[Dr. Dyno]

I'd be surprised that I'd need new springs with such a small increase over stock lift (stock= .408, CompCam = .462). I would also think that if I required new springs they would have included them with the kit (I searched and didn't see this cam in a kit with new springs anywhere). I'll talk with my builder tomorrow and see what he has to say. Thanks for the input.

Thanks for the info on the stroker, but I dont' think it's a direction I need to go. I've also heard that the stroker isn't too freindly on the MPG either.

You're forgetting that the exhaust valve lift on the 231 cam is 0.485" so you definitely need to upgrade the valve springs. The CompCams springs don't work on the 4.0 head but the Mopar #5249464 springs, #4452032 retainers, and #4529218 locks (single groove valve stems) fit on the 4.0 head without any machining work required. I used them on my stroker for the first 34k miles when I had the Crane 753905 cam.
I wasn't suggesting you build a stroker but you might want to reconsider since you'll have the engine apart anyway. I'm actually getting slightly better gas mileage from my 4.6 stroker than I was from my old (but very strong) 4.0, and that's largely 'cause the extra torque makes the Jeep more effortless to drive.

 

[tcervinsky]

Well, I'm not sure what to do now. I just got my quote for rebuilding my engine and it's a bit more than I expected. All the while he kept telling me what a great core I've got. Engine to be bored 20 over, new pistons, bearings (rods,mains,cam), polish crank, new factory spec cam, cam gear and chain set, ground valve seats, new valve seals, new expansion plugs, gasket set, new oil pump with pickup tube, all put together out the door for me.... $2300. I believe Quadratec sells a long block for about $1800 (plus core). Seems strange to me that I can't get one built locally for less.

 

[Dr. Dyno]

Looks like a stroker rebuild has now become a more attractive option.

 

[seanyb505]

Why do you need the motor "freshened" in the first place? If you don't want to do a stroker, but are looking at spending similar money anyway I would just run the engine until it does die, then rebuild. Two things: strokers are only as reliable as the person who built them, and a properly tuned stroker will see no decrease in MPG depending on how you drive it. Not trying to convince you to do it, I just wouldn't let those two concerns stop you if you kinda wanted to go for it.

 

[tcervinsky]

The mention of a "stroker" Jeep motor has come up a couple times while talking to the engine builder, but I bet at these rates I would be looking at well over 3K- more than twice what I expected to have into it. You have to remember, we're talking about a '97 Jeep Cherokee- a vehicle that many, even here on this forum, would have a hard time paying more than a couple thousand for a complete running/drivable Jeep.

I wanted to "freshen" up the motor because it's a yard motor- I didn't know it's history other than check the mileage of the vehicle it came out of and checked the sprark plugs. It had just over 100K miles (jeep was wrecked) and the spark plugs were nice and tan. The block was from a '95 but Chrysler went to a dual patteren cam by '97, and I've read several places that the dual patteren cam is a better choice. Also was recommended to keep the computer happy.

The bearing were definately worn- I can see copper. Crank is in good shape, just needs polished. Pistons had some wear, but it was explained to me that if I hone the cylinders and try to use these old pistons there will be too much play. Not only will it be noisy but the pistions will be prone to crack. So a mild bore and new pistons are needed. Thats replacing everything in the block except the crank and rods- which is what I need to replace to do a Stroker.

I'm going to do a quick search for a 258 crank and rods today, probably call the builder and see what his price is for them new and see if I should be considering this more. Give me you're most reliable storker receipe

 

[seanyb505]

Mine is a 97 as well. I don't want you to think Im trying to convince you to build a stroker, I just want you to be aware of what it may entail.

The most reliable (and since it does matter to you) inexpensive way to a stroker would be new crank(which will include bearings) rods, and maybe decking the block. You're already getting a cam so that's covered, everything else is already there. You may want to do something about the injectors, most people go with a 24# Ford Motorsport injector. Doing it this way definitely will add cost to your build, it's just a question if you want to. There's nothing wrong with building it stock; it's only a question if you're interested in a little more power.

SCAT crank produces newly cast cranks. Not remans, new. I picked one up from a distributor for 390ish with bearings. Ebay a set of 258 rods, or look for a local deal. I would say if you buy your own set you could be looking at some machine work. Most sellers already have it done. Compare costs. I think decking the block is like $20-30 depending on your shop. Injectors are another variable. There are different ways of going about it. You'll have to make your call. I picked up a set of 8 Ford (not the Cobra) injectors that had one damaged injector. I didn't need all 8 (obviously) so it was a great bargain. It all depends on how much effort you want to put into looking.

The basics are not some mystery that everyone has to guess for their build. It's when people start looking for a different way, significantly more power or cutting corners that strokers get into the unknown.