Configuration advice: 98' XJ 4.7 build

[HkyPnky]

Hey from Arizona! Been scouring the site for a while. Finally getting around to posting for the first time.

I have a 98' XJ 4.0 l6 4x4 w/ the forest edition. It was a CA state truck that was sold to AZ after being designated a gross polluter lol. It's got about 225k on its original block that is overheated several times, despite a new upgraded cooling system. So I've set out on a mission to replace the engine with something a little more fun for the next 220k; and have decided on an original upgrade the stroker.

I would love to build the whole thing from the ground up but down time and warranty is important to me, so I will likely be buying a assembled block with a 3/yr 100k warranty.

I have been looking at a few online like:

Golden Stroker - $4,300.00 w/upgrades

MHA Creations Fab & Off Road Stroker - $3,100.00 w/warranty

Summit Stroker - $2,949.00

4Wheel Parts Baja Stroker - $4,320.99

Engine House Stroker - $2,350.00

505 Performance Stroker - $3,650.00

It looks like a lot of the sites sell the same engines just under different names so I was not sure of any others as being a opposing option.

The type of jeep I want to build is more of a Baja sleeper. I want a daily driver/smog passer with an engine that will last another 200k, burn up small cars on the street, capable of hitting quick trails and baja runs. All while appearing near stock on the outside. I probably will not be lifting it or getting much of a bigger tire. Probably a thin bfg at when I can get some rims with an offset to bring the wheels out. 300 HP is a minimum but want to build upwards of 350 while staying n/a to keep longevity.

I have collected some parts already like: Gibson Ceramic Header; Screaming demon kit; Flowkooler water pump; HF thermostat housing; Fail safe thermostat; RC9YC4 plugs; belts; gaskets.

I have a few more things in sight as well: 7120 ported head; 99+ intake; Afe CAI s2; 62mm tb; 24-27# injectors; J&C cables; Custom exhaust w/ HF cat; Tune by FlyinRyan.

I am eager to hear your advice on blocks and configurations I should consider for the type of build I want.

[jsawduste]

From what I am reading your on the West Coast or near it.

One person and only one person in your approximate area I would use is Russ Pottenger.

Search for his name on this forum and drop him a PM.

[HkyPnky]

Thank's for the tip, looks like he does some good work with an impressive jeep himself. West Corvina is within 6 hr from me, so that's not too bad and a beach stop is a plus.
I will reach out to him tomorrow and ask to pick his brain a little.

I forgot to mention It has some weight already with full steel skids and copper radiator.
I might add 1-200lbs from interior/exterior installed extras.
I also wanted to stay with 91 pump gas.



Also been thinking about the tranny and putting power to the wheels. Which will be exponentially harder at 350hp.
I believe I have the AW-4 auto, Chrysler 8.25 and 231J (272) Tcase.

[SilverXJ]

I believe the 4wheel parts stroker is made by ATK. I owuld also advise staying away from 505 as I have heard nothing good about them.

I will second jsawduste's recommendation of Russ. While I have not had dealings with him personally I have heard a lot good about him and from him. If I started from the beginning again I would have definitely given him a call.

As for your AW4 I recommend you get in touch with Chad at http://www.fringexvo.com/. He does valve body modifications on the AW4. I have one of his valve bodies and it is quite nice in how it shifts. Nice and firm without being harsh. I also recommend you install a larger cooler if you haven't already. The AW4 is not weak and will take a lot of power.

About the flowkooler water pump. I had one of the earlier versions with a plate riveted on the back of the impeller. Along with a HF t-stat housing, hf t-stat and a CFS radiator. After the cooling systems modifications I could not keep it under 210* on the highway. I replaced the flowkooler water pump with a stock one and cooling went back to normal.

[HkyPnky]

Thanks for the imput, I am finding 505 to be frequently labled as bad apple throughout the forum land. I will be removing them from the running.

I will check out that valve body when I get home, appears it is blocked at work.

I see they are both ATK but one is a "baja" stroker and the other a normal one. Not sure the whole difference?

I have seen reviews like your's on the flowkooler, and some good one's too. From what I read it looks like some have good luck with regualr flow tstat and HF housing/pump. I am prepared to bring it back to stock if needed. The housing and pump on my old block are brand new and will be saved if needed to remove the flowcooler. Did you try a normal Tstat with the HF pump/housing?

I do have a CSF 3 row radiator too.

[SilverXJ]

Did you try a normal Tstat with the HF pump/housing?

Yes I did.

I would be interest in seeing your results with the flowkooler pump. It won't hurt your engine during break in. Is it the billet impeller or the older plate style?

[HkyPnky]

Looks like its cnc'd and bolted on.

image.jpg

[Cheromaniac]

Thank's for the tip, looks like he does some good work with an impressive jeep himself. West Corvina is within 6 hr from me, so that's not too bad and a beach stop is a plus.
I will reach out to him tomorrow and ask to pick his brain a little.

I suggest you source a secondhand 4.0L long block from a '96-'99 XJ and hire Russ to build you a stroker. He'll advise on what parts you'll need and he can even port the head for you. What do you think of this as a starting point?

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Bulltear custom +0.030" pistons
9.6:1 CR
CompCams 68-231-4 206/214 degree camshaft
Russ Pottenger ported HO 2.00"/1.55" cylinder head
Mopar/Victor 0.043" head gasket
0.043" quench height
Ford 24lb/hr injectors
268hp @ 4900rpm, 326lbft @ 3500rpm

[HkyPnky]

Thank's for the reply, It appears from the comments that Russ will not have pre made blocks and I would need to provide the block, but that would be more configured to me.
I was reluctant to pick out my own, I did not want to mistakenly grab one that's unusable. Same thought with the one in the jeep now, with the overheating I only assume the worst.
I will keep an eye out for one and see if I can get it at a steal.

For the configuration I was thinking a bit more aggressive at:

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Keith-Black UEM-IC944-060 pistons
10.2:1 CR
CompCams 68-235-4 210/218 degree camshaft
Russ Pottenger ported HO 2.00"/1.55" cylinder head
Mill block deck 0.030"
Mopar/Victor 0.043" head gasket
0.040" quench height
Flometrics F&B 68mm billet TB
Accel 26lb/hr injectors
290hp @ 5100rpm, 340lbft @ 3750rpm

With header, upgraded spark, CAI, 2.5 exhaust and PCM programming. It should be well over 300hp.

I was wondering about using a 4.0 crank because of it's strength, would it be a big difference?

[Cheromaniac]

I was wondering about using a 4.0 crank because of it's strength, would it be a big difference?

LOL, yeah, I should say so. The heart of a stroker is the 258 crank so if you use a 4.0 crank, the engine won't be a stroker anymore.

[HkyPnky]

Guess ill have to read long vs short again. I must of misunderstood it.

[jsawduste]

Same thought with the one in the jeep now, with the overheating I only assume the worst.

That`s a tough one. The deck could likely be twisted but your knocking some meat off. The mains will (or should be) align honed. The bores will be freshened up and made straight again.

I`d gamble with it and let Russ decide if the block is rebuildable. That said 4.0 blocks are pretty cheap but then again you don`t know the history of a used one. It too could have been overheated.

[Russ Pottenger]

If you don't have a suitable engine or core, I have pre machined cylinder blocks sitting on my floor ready to go.
Same go's for ported HO heads.

I stock and recommend using Scats nodular iron Crankshaft.
It may not have the strength of the steel forging, but is definitely stronger than OEM 4.0 or 4.2 casting.

I'm working with RaceTec on a improved piston for the 7120 head. We should be done with it
by the end of next week.

Fill free to contact me if I can help or answer any questions.

Russ Pottenger
Bishop-Buehl Racing Engines
531 N. Lyall Avenue
West Covina, California, 91790
Work (626) 967-1000
Fax (626) 967-7836
Cell. (626) 673-2203
Email/PayPal: [email protected]

[jeepxj3]

I'm working with RaceTec on a improved piston for the 7120 head. We should be done with it
by the end of next week.

Nice, can't wait.

[HkyPnky]

Thank's so much for the free education today Russ, I really appreciate the help!

I definitely understand more of where I want to focus and put extra attention on. I'm excited that my prospect is 100% achievable.

Once we nail down the build specs ill share with you all what exactly we will do.

Still on the fence with 7120 ported and eddlebrock ported. It's about 1k difference and 7% improvement over 7120.

Going to get the 99 intake port matched and hopefully spring for rocker upgrade.

Also going to look into aftermarket motor mounts, mine are brand new but Russ talked good about some that mount to a large section of the block for more stability.