After discussing my port work with one of my instructors who used to run the port work shop for Lingenfelter, and my instructor/machinist we came to the conclusion I need a bigger cam. With all of my schooling in port design being focused on race motor applications, even though I tried not to, I made my ports to move a lot of air. In combination with the idea of using the LS valvetrain, the desision was made that the 68-232-4 just wasn't big enough to take advantage of the work I had done/will be doing, so I'm looking at probably the 68-235-4, that will also give me a bit more mid range power. The 4-239-68 is a lot more radical cam, for more high end torque and compression that will be great for those "Hammer Down!" moments, but I'm not sure I want to go that radical just yet. We'll see once I get it running.
No you want a comp 239, retard 3 or 4 degrees! That way the power band shifts to the left..IE lower in the rpms, but you still get the duration and lift
Just gotta think it through lol..The comp 239 is a high rpm screamer, but it has been retarded enough to run in a stock 4.0 xj..so your stroker 4.7L will have no problem with it!
He's running it retared 3*, in a stoke 4.0. You will love this cam! When you retard it, it'll idle just fine, a little lope but no vaccum issues or anything like people "claim"..and again since your running a 4.7L..more cubes, it'll turn this cam without issues! Hes got a 97+ which are even more finicky..and he's idling at 800rpm without issue lol. Get the comp 239 and retard it a few degrees
And Pm me I've decided I'll be swapping in a om617 diesel..a Merc 3.0 5cyl So I'm selling everything I had to build my 4.0 stroker. I'm on jeepstrokers.com as well, same user name! You can buy my whole LSx valve train, its ls1 stockes,retainers & locks and Z06 springs which can handle any aftermarket cam for the 4.0.
For install you'd need to open up valve seats to 2.00/1.55 and grind down the spring seats so you get a 1.75" install height..its as easy as that lol, these will add 2.8cc per combustion chamber because they are tuliped undersides, thus giving you more room CC, thus a slightly lower compression ratio, thus you can tighen your quench height up! Shoot me a pm, I've got alot of stuff that I'm gonna sell, 99% of its all brand new never even opened lol.
Block is still at the Machine shop, his mother has been really sick with heart problems the last few weeks, so he hasn't been getting a lot done around the shop, not a big deal since I still have plenty to keep me busy with the head. He is doing the work for free, so I wouldn't complain even if I wanted to.
Still porting on the head, intake ports are all roughed in, and most just need polished, I'll wait till after it gets back from getting all the machine work done, and can blend the bowl in to polish. Going to hit the exhaust and combustion chambers next.
Last side by side comparison.
M.O.R.E Bombproof engine brackets showed up, asked for them to leave them tacked, just incase I need to do any modifications to make the clean sheet block work in the MJ, if I need to make any modifications all I will have to do is cut a few tacks, rather than cutting entire welds.
I did end up ordering the COMP Cams 68-239-4 cam and lifter kit, and I did decide to run the LS1 valvetrain, just checking options as to where to get them now.
None. Been busy as hell opening up a new store, got something of a promotion to Assistant Manager in-Training/comercial sales manger. The guy they hired to be the manager had about 3 weeks training in the company before they dumped him in the store and said "good luck". Needless to say he's needed a lot of my help, and about 2 months in to it(about a month ago) he finally realized that.
The last couple days is the first time I've been able to touch the Jeep itself since March, feels good to be back at it. I did get a voice mail last week from my machinest, telling me to come get my stuff. Don't know if that means the machine work is done, or if he just wants it out of his way since I haven't been able to come down and help work on it.
Sorry to resurrect this thread - it's similar to something I'm dealing with. I have the 239-4 in my 4.6 stroker with 24# injectors and 63mm TB... and a really rough idle. I thought that the way to shift the powerband left was to ADVANCE, not retard the timing.
Can someone explain this to me a little more, please? I'm new to this.
Since I'm still in the gathering parts I won't be much help as far as diagnosing the problem, you will have a lit more luck trying your luck at jeepstrokers.com, plenty of guys there will be able to help.
Slight update that came up today, although not directly related to this build, it does effect it. One of my co-workers just did an engine swap on a 02 WJ 4.0, and has the old engine laying around. He asked me if I have any use for it, and me being me, I said yes..... I'll find a use for it.
This got the gears turning, I've got the 68-231-4 cam and lifters laying around, and I've been looking for an excuse to get that Skat stroker crank.... Just a mild port cleaning on the head, grab a set of 4.2 rods to put with my crank, grab a set of .040 over 4.0 pistons through work..... And then I remembered that O'Reillys has a machine shop at the headquarters in Springfield, MO that does engine work. So I called out there and asked about the process of getting work done, the parts are shipped out with a work order from the store and sent to Springfield, works done and it's shipped back. I asked about how the process works, cost wise for employees and the guy didn't have an answer, but he did give me the number for the machine shop, I'm going to call on Monday. I'm going to venture to say that it won't cost much, if anything at all since it's mostly just labor, and the shipping is all going to happen weather my engine is going or not, it would just be hitching a ride.
I think I already have a guy interested in the motor, which is a good thing, to help fund the cost of the items needed to finish the build. I'm including the crank, cam, and lifters I have already, block and head too, as well as some of the other odds and ends laying around. The only thing I'd be getting out of it is the Skat crank, a JBA header, and his old engine. And since this person is comming back to work for O'Reilly, I'll let him buy all the rest of the part needed, bearings, gaskets, pumps, etc.
Alright, I guess it's time for some sort of update. I went down this weekend to the machinist and picked up the motor, NOTHING has been done to it in the last year. I was supposed to be getting the machine work done for free as part of me taking the class, a major reason I took the class a second time. I had ordered some parts though him because has was going to be doing the machine work for free, even though I could get a better deal through work, but he makes a profit off selling parts so I figure it was only right since he was doing the work for free. I paid him for the parts I had already ordered off of him, and took everything that was mine. I'm going down to the school to pick up my engine stand and finish paying him for some rod bolts and that will be the last I work with him. I'm going to go back to finding the parts myself, and I'm going to have O'Reillys Machine shop in Springfield do the machine work for me, I get a 25% discount as an employee, should get all of my block work done for less than $200. going to try and find a shop locally to press my pistons on the connecting rods, and start doing some searching for a machine shop to deck my head and do the machining for the valves and valve springs.
As much as I would have loved to have him do the machine work on my block, after seeing how OCD he is about his work, I'm going to go else where out of principle. I've picked up enough from him to make a difference in assembling the motor myself, which I am perfectly comfortable doing. I need to start searching for this machine shop near buy that I hear specializes in the AMC I-6, can never get a name from anyone though.
Got the engine all packed up for storage for a little bit, atleast until I can get funds moving again. Trying to juggle the wants for the MJ project and the needs for the DD and wants for modifying it.