'99 MJ Project - Possible Stroker Build - HELP

[go4lo]

Whats up guys....I need some help from you. I'm in the process of converting a '90 MJ to a '99 MJ using a '99 XJ as my donor vehicle. I'm pulling the motor from the XJ this weekend and plan to start tearing it down. The XJ ran fine before but it has high miles and is in dire need of all new gaskets as seals including a head gasket. I've already spent way to much money on this MJ but since I'm going all out on it I'm considering an engine rebuild as a stroker before it goes in.

The goal for the MJ will be a weekend expedition vehicle to use on long trips camping and off roading. It will see moderate highway time so being able to travel at highway speeds for extended times crutial. It will be on 35s with 4.88 gearing. I'm in NC so elevation shouldn't be an issue. I really want to be able to run 87 or 89 but I can live with 91 if necessary. I plan to do all the work myself other than the machine work. I'm thinking a mild 4.6L build reusing a lot of the existing 4.0L HO parts.

A few pics of the project....







Current engine specs -'99 4.0L, 173K, 0630 head, std distributor ignition(no coil packs)

Working plan.....PLEASE ADVISE:

Parts:
Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Sealed Power 677CP +0.020" bore pistons
What Rings?
What head gasket
Reuse stock 4.0L HO Cam, Lifters, Push Rods, Valves, Springs, Rockers...etc.
New bearings and seals throughout
Ford 24# Injectors

Machine Shop
Block - prep, clean, bore .020, hone, install cam bearings, .00 deck
Head - clean, deck .00, 3 angle valve job, port/polish?

Bolt Ons
Passetter Header
Full 2.5" Exhaust, Carsound Cat, FM 40 series
Bored Throttle body 6?mm
Cold Air Intake
FlowKooler Water Pump
Robert Shaw 195* T-stat
CSF 3 Row Radiator
What Ignition Set up?

[SilverXJ]

What Rings?

Molly rings to fit the pistons. Hastings makes some very good rings.

What head gasket

Go with the .044" Mopar Performance head gasket variety. The Part numbers are in the FAQ.

Reuse stock 4.0L HO Cam, Lifters, Push Rods, Valves, Springs, Rockers...etc.

Makes sure that cam is still good and if you reuse it keep the lifters on the same lobe or you will be replacing it any how. However, I do suggest a new cam and lifters.

port/polish?

Do a simple home P&P. I have a post here on my work plus there is a post recently with some good info in it.

6?mm

63mm from strokedjeep.com

What Ignition Set up?

Which parts are you interested in changing? I've heard to stay away from Accell and go with MSD.

Your MJ looks great so far. I hope you keep us updated on the full project.

-Chris

[dwg86]

Opinions vary on this, but I would not reuse a cam, lifters, or springs that had 170,000 miles on them. If you want to reuse your valve springs, stock valve springs are only good for up to .450 valve lift. You can check several cam manufacturers, Isky, comp, bullet, ect to see who have cams that have less than .450 lift. I know comp has two cams that will work with the stock valve springs, part # 68-200-4; 206 dur @ .050 and .433 valve lift, and part # 68-201-4; 212 @ .505 and .447 lift. Do not buy a comp K kit. Those kits are built for the 258 valves. The retainers, locks, and springs WILL NOT WORK on the 4.0 valves.
Crower has a cam part # 44915; 208 dur @ .050/ .448 lift. Isky has 4 cams with .450 or less lift http://iskycams.com/onlinecatalog.html

[Plechtan]

Looks like you have installed the wiring harness and ECU from the 99 into the MJ, Correct? I am not sure if the 99 has the cylinder head with the casting number 0331, if yo do have one of these check the threads related to them, they are prone to cracking. You will need to use the flyhweel off the 99 to send the proper crank signals to the ECU. The Renix flywheel has a different number for notches.

As far as your choice of parts, i would stick with the 4.0 rods and use the KB944 pistons. By the time you buy new rods, and get the pistons dished deeper, it is just eaiser.

[SilverXJ]

Looks like you have installed the wiring harness and ECU from the 99 into the MJ, Correct?

Good eyes. It looks like he did.

I am not sure if the 99 has the cylinder head with the casting number 0331, if yo do have one of these check the threads related to them, they are prone to cracking.

It shouldn't have the 0331. The Xj got the 0331 head in 2000, the WJ in 1999, and I don't know about the TJ.

[go4lo]

Hey guys, thanks for the replies! Here are few more specs on the engine and answers to you questions.

Block Casting date is 9/4/98 - NVH block
0630 head cast into top of head on exhaust/intake side(I've been down the 0331 road before with my TJ....had to put a new head on it)
Yes, I'm using everything from the XJ, wiring harness, ECU, AW4 Tranny so no flywheel issues

What do you guys think about this combo:

4.2 Crank
4.2 Rods
H825cp30 Pistons(will they need to be dished?)
P4529230ab - Mopar Cam 256 dur./ .450 lift
P5249464 - Mopar Valve Springs - 5.2/5.9 magnum V/8 w/damp to .525 lft


The XJ ran great before disassembly, however most of the seals are leaking or oozing, hence the reason for the tear down. Because the Jeep ran great, I had considered reusing the cam, lifters and valve springs to save some $$.

We got the motor out of the XJ yesterday and cleaned up. I plan to tear it down this week so we'll see what she looks like inside. I'll keep you updated.

[dwg86]

Oletshot on this board can dish the pistons. Great work, price and fast turn time.
The mopar 30AB cam is no longer available. Niether is the 29AB.

[gradon]

That's the combo I used for my stroker and it's working for me(partswise--I used a 94 block(w/ 96 girdle) and head(7120 that I p&p'd, so it breathes on the high end where the 30ab shines). If you can find the 30ab, buy it. I'll be working on a stroker in a 90 MJ in the near future.

[go4lo]

That's the combo I used for my stroker and it's working for me(partswise--I used a 94 block(w/ 96 girdle) and head(7120 that I p&p'd, so it breathes on the high end where the 30ab shines). If you can find the 30ab, buy it. I'll be working on a stroker in a 90 MJ in the near future.

Where did you find the 30ab cam?

[gradon]

http://www.jeepconnection.com. They had to get it from someone else's inventory, and at that time(Jan 07) they could only find three in the nation. A 28ab and 1.7rrs would be a good substitute.

[go4lo]

I made few calls this morning and found both of these cam/lifter packages available:

P4529228ab 240 dur./.430 lift
P4529229ab 248dur./ .440 lift

What are you guys thoughts on using the H825cp30 Pistons dished to 18cc with either of these cams?

Also both of the cams above call for the P4529214 spring (4.0 1981-87 cylindrical to .430lft) vs. the 30ab cam calling for the P5249464?

Would I need to have the block decked .010 to run this gasket set P4529245?

Thanks again for all your help.....Just trying to figure out the most reliable recipe.

[gradon]

Get the 29ab and the P4529215 springs(you can reuse your retainers and keepers if you want). Forget about that particular gasket set, as it is a fel-pro cork set(.051"HG, cork valve cover, 3 piece cork oil pan, etc). I like the nicer fel-pro rubber gaskets for the valve cover and 1-piece oil pan. I also prefer the Victor Reinz HG, so you might look for one of those.

[dwg86]

Make sure you can put your hands on the 29ab cam. Sometimes it will show "in stock" until they actually try to ship it. That has happened before with the 30 ab cam.

[go4lo]

I was on the 505 performance website earlier looking at the Pro Rock Economy Stroker kit for $1089. It says he is using Keith Black pistons, anyone know which pistons and are they being dished or just used out of the box?

I guess, what I'm getting at is could this kit be pieced together for cheaper than the price 505 is selling it for?

[gradon]

Someone posted a few weeks ago a link to the KB944s that could be had for ~$350, so search around here. I don't know if that included the rings.