Looking for some advice, building a 4.7

[live24wheel]

I am going to be starting on my 4.7 in a couple weeks, as soon as I get home, to put into my 2000 XJ. What I have so far is a donor motor out of a 97 XJ, and have ordered the KB944 0.060 pistons. Figured I would get the biggest "part" expense out of the way. From what I understand the bracket mounting will be different between the 2 motors, im not too concerened to source them as I got the short block for $25. Let me tell you what the general use of my XJ is. It has an automatic, I use it for some street driving, crawling, and prerunning. I plan to later put a manual trans into it, may do it if I can find one when I swap the motor. I am looking for some cam and crank advice. I was going to run a Comp 68-231-4. I played with the compression calculator some but have no idea what the advance or retard will be to calculate it. I figure I wont be able to get the deck height until I can get the pistons and all installed to measure it, to find out what my quench will look like... I keep reading in different places that quench isn't really important on the I6 builds, from what I read here, it seems the opposite. Can I get some advice on cam choice? As far as crank, I have read that the 12 CW is the way to go, figure it may be easier on the motor parts as well when under throttle hitting whoops and stuff. I think I read on Pirate that the only way to go is a 4 CW. So, Crank adivce? Any other problems I may need to be worried about putting this into a 2000 cherokee? Since this is a 97 block, and the whole exaust and dual down pipe deal, will an aftermarket header for the 2000 bolt up to whatever head I find? Also, im sure a more common question, where to order a crank? I also have leads on a guy that can do a full port/polish job on the head with a flow bench but its gonna be $$$. Is it going to be worth the money? What kind a gains do you think I could possibly expect with the port/polish?

Sorry for all the questions, wanted to get them out of the way to avoid using the phones internet to ask questions.

Thanks, Tom

[live24wheel]

I was doing more research on the cranks and it looks like a 4 CW crank might be a better option. I do more prerunning than crawling, I really dont do much hard crawling anymore like I used to... Just the basic flexy trails and stuff. Acceleration will be important. What do you guys think? I was looking at Rock Auto's site and the difference between a 12 CW and a 4 CW is about 80 bucks... I don't have a core to send back. How do you ensure they haven't been ground too much before you order them? I keep reading 10/10 is the most desireable but what is the limit you want it to be ground? I am looking for any advice or thrashing or whatever. Any tips would be greatly appreciated.

Thanks,
Tom

[SilverXJ]

For the header you can use an earlier header and have O2 bungs welded on. Also, you would need some O2 sims for the after pre cat O2 sensors if you have the Cali emissions package. I have heard that the after market headers for the 2000 have big enough piper to accommodate both pre 2000 and post 2000 head exhaust ports. Supposedly there is also someone floating around making adapter plates for the earlier heads to the 2000+ manifold, but I haven't actually seen one any where and feel that that is more of a bandaid fix.

I recommend a 4wt crank as it is lighter and I have never heard of wither crank breaking in stock RPM use. The 12 wt may benefit a manual gearbox though. For suppliers like Advance, Autozone, and Rockauto you don't know what you are getting until you get it. Also, check the for sale here as there seem to be a few floating around there.

As for the port and polish I suggest you just do a simple clean up and polish on your own with standard abrasive's kit.

[IH 392]

I'm not convinced that a 4 wt crank will out accelerate a 12 wt crank?, the 12 wt's have better harmonics, the only reason AMC went to the 4 wt was it cost less and proved reliable in service.
You probably would never feel the difference on the street, maybe on the strip???
But it is $80 cheaper!

[live24wheel]

Awesome, thats what i was looking for. How about Cam choice? I was hoping to get a MP 30 with the wider lobes but that is proving difficult to track down. Thx, Tom

[gradon]

Good luck with finding the 30--jump on it if you do find it. Isky seems to be a good option(silver mighta had an issue w/ the customer service though).

[SilverXJ]

Yeah.. Isky's customer service is complete fail. Check out bullet cams.

I'm not convinced that a 4 wt crank will out accelerate a 12 wt crank?, the 12 wt's have better harmonics, the only reason AMC went to the 4 wt was it cost less and proved reliable in service.

Same here. the 4wts are easier to find though.

[live24wheel]

So I just talked to my Machinist guy and I guess he deals directly with Isky and Comp. I have the PN I was looking at for a Comp, 68-231-4. Can you guys recomend me the Isky PN? I found 6 PN's here http://www.angelfire.com/my/fan/Jeep4.0Camshafts.htm for use in the 4.0. I will be honest I have read and read and Cam numbers are liking someone speaking Mandarin to me. I understand how it effects compression and what not and the best I can do is type them in and see what it does. Any recomendations? Thx Ohh and also, he said he could get me a core 258 crank for $75 and regrind it for another $75 or so.... Ballpark figures but doesn't seem too bad.

[gradon]

$150 for a worked crank is reasonable. I believe sean is using the 133125/26 cam successfully(although he has oil pressure issues at the moment). You can check out his build in the project section(will be down a ways). I don't recall what isky cam Chris(silver) used or what exactly happened to it(cam walk?). I don't think you can go wrong with the comp 231--it seems a lot of people use that one.

[SilverXJ]

The Isky cam i have is a 258-mega/264-mega, which is 258*, .464" on intake and 264*, .480" exhaust. When itw as running I liked it. It didn't have as much valve noise as the Comp, and performed reasonably well. However the cam was out of round. The cam bearings were destroyed, but we don't know if it was a result of the cam being out of round or something else. There is no conclusive proof as to what happened. However, Isky's customer service was horrible. They took too long to do any thing, never returned phone calls, and then tried to tell me that it was my idea for Ron to talk to my machine shop. I don't recall how long the whole process took.. 3 months maybe?

[live24wheel]

Ok I may just go ahead and go with the Comp cam. As far as the crank goes, I payed for one today. Its the 4 CW long snout crank. My Machinist guy was unable to locate one and I was able to locate this one at a salvage yard. Still be the same price $75 for the crank and $75 to have it worked. Im following the thread on the 4.6 build thats running along side this thread, has alot of the info I was looking for running the KB944's. I figured I would catch some heat for asking so many questions, really appreciate your guy's advice and tips. I just need to start researching compression numbers and how that all plays out. Im not to worried about having to run 89-91 octane. The Jeep really doesn't get driven much anymore since im barely in town. My DD is a 09 Kenworth W-900

Tom

[live24wheel]

Hey guys, bare with me as im typing this from my phone. My dad went and checked on the harmonic balancer from my 97 donor motor and said it looks good just that there is a rubber piece that looks a bit weathered. Do you guys think it will be ok to have balanced for my build. If not can you tell me the best place to get one. Also i need to source a flywheel. Any advice on where to buy one? It will be balanced as well. I also am wondering about the whole cam position sensor deal as this is going into a 2000. From what I have read it runs off the oil pump drive. I Havent got the chance to see it but will i have to worry about the distributer hole on the 97 block? Will i need to get an oil pump for a 2000 and will it bolt into the 97 block ok? Thanks!

[live24wheel]

I may have answered my question about the oil pump. Looks like both years use the same p/n. I actually meant flex plate, not flywheel, its got an auto. The internalls will all be balanced and matched. Also the harmonic balancer will be balanced. Is it important to have the flex plate balanced or is that mainly for a flywheel being that it weighs more? Thanks

[SilverXJ]

You will be fine with the cam sensor in a 97 block. The oil pump for all years of the 4.0L is the same.

[live24wheel]

Can someone explain to me how Dino came up with a 0.051 quench on the med. buck stroker, 4.7? Im going to be running basically the same parts but to get my quench that low or lower, even with the 944's, my CR starts worrying me.It says deck the block 0.020 and run a 0.043 head gasket. I cant figure out how that calculates out to .051. I have no problem running 91, just want to make sure im not calculating wrong. Thanks.