Planning/Questions for a 4.6L in an '01 XJ

[sirrobin]

Howdy,

This is a combined questions/log thread. I'm looking at building out a stroker for my '01 XJ. The final goal is to wind up with something in the 4.5-4.7 range, puts out 310+ ft-lbs and can run on 87 or 89 pump gas. This is my daily driver/road trip vehicle so I'm going for reliability. (I know, I know ). We'll see if it can be done.

I'm still doing a lot of research and will be updating this regularly as I learn more. I'm a fair hand with a wrench in a general sense, but I'm completely new to engine internals.


Here's what I've got in terms of a parts/labor list so far (Yup, I did a lot of digging and shamelessly stole from Dino's performance site to put together the base list while I learn enough to adjust it if needed):
Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Keith Black UEM-IC944-030 pistons
CompCams 68-231-4 206/214 degree camshaft
Russ Pottenger ported HO 2.00"/1.55" cylinder head
Mill block deck 0.020"
Mopar/Victor 0.043" head gasket
0.050" quench height
Ford 24lb/hr injectors
Upgrade exhaust and throttle body.

I think this is a pretty standard mildish recipe for a 4.6 with something like a 9.6ish compression ratio and should get....260ish hp, 320ish torque?

So here's my questions to start with (I'm trying to answer these myself and will update the post as I manage it):
1) If there was anything that was really helpful when you first launched down the stroker road I'm taking all inputs. I've done a lot of reading so far but I'm eager for more.

2) Where have folks had the best luck sourcing parts? Part of my research is trying to build up a cost estimate but it seems like things are unpriced or all over the place in my web research.

3) Any comments on the parts list so far? Objections? Something I'm missing?

4) The two things I know I'm not sure about:
a) What block to start with. It seems like a 97-01 would be the desired range to swap into my 01 after the build. With 00-01's having to be watched really carefully for the 0331 crack issue.
b) PCM? I don't see a lot of commentary on this, but can a stroker run on a stock PCM, seems like it would lose it's mind.

5) Any recommendations on a good machinist to use in the Dallas area would be MASSIVELY appreciated. Trying to find a dude on google is a crapshoot and I'm going to need to talk through the deck mill, overbore and restoring a 4.2L crack at the very least. Lots of other questions as well on that (parts cleaning, having a used head ported instead of buying new, magnaflux, etc).

[SilverXJ]

4) The two things I know I'm not sure about:
a) What block to start with. It seems like a 97-01 would be the desired range to swap into my 01 after the build. With 00-01's having to be watched really carefully for the 0331 crack issue.

Block is independent of the head. The head has the cracking issue. As far as damage from the cracked head in the block I wouldn't worry as you are rebuilding it anyhow. Stay away from 99+WJ blocks and 00+ TJ blocks.

b) PCM? I don't see a lot of commentary on this, but can a stroker run on a stock PCM, seems like it would lose it's mind.

[email protected] for tuning.

[Retlaw01XJ]

Keith Black UEM-IC944-030 pistons .....

2) Where have folks had the best luck sourcing parts? Part of my research is trying to build up a cost estimate but it seems like things are unpriced or all over the place in my web research.

I built my '01 a few years ago similar to your plan with a milder Crower 44243 cam. With it's lower valve lift, you can use stock valve springs to keep costs down.

KB pistons are $402 from RPM Machine. Or watch eBay for deals. Some have been for sale on the board here as well.
https://rpmmachine.com/kbpistons-premiu ... -amc.shtml
A very good alternative is to use the pistons from Bulltear. There are built to spec so they don't require block milling to get the compression where you want it. Cost is comparable at $475.
http://www.bulltear.com/catalog/product ... cts_id=242

General engine parts, Falcon Global on eBay. They have build kits listed but it's better to call them if you want to customize the parts list, such as picking the manufacturer of the parts. Get the ARP rod bolts too.

My PCM is okay with the build except for the first minute or two when it's cold. Runs lean and rough until it goes into closed loop, then it's smooth.

[Cheromaniac]

I'm happy that you did take the info. from my site and used it to formulate a plan. There's one small change to that recipe though:

4.6L low-buck stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Bulltear custom forged +0.030" pistons, 1.380" compression height, 23cc dish (assuming 57cc chambers)
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 for '96-'04 engines
268hp @ 4900rpm, 326lbft @ 3500rpm

If you're going to build a stroker from scratch, a '96-'01 XJ block would be the best starting point so you won't have any compatibility issues with engine mount bosses and the water pump bolt holes. As far as the head goes there are two good options; either a Clearwater reinforced 0331 head or a used '02-'06 TUPY head from a WJ or TJ to avoid the cracking issues that you might run into with your '01 XJ head.
As far as PCM tuning goes, SilverXJ has already given you the best advice.

[jeepxj3]

Russ Pottenger ported HO 2.00"/1.55" cylinder head

This head doesn't sound like '4.6L Low-Buck Stroker'.

[Cheromaniac]

Russ Pottenger ported HO 2.00"/1.55" cylinder head

This head doesn't sound like '4.6L Low-Buck Stroker'.

That's why there's also a "poor man's" option.