Head Swap

I just got a `93 4.0 AW4 4X XJ 170k really cheap, I bought it from the company that towed/stored it. Here's what I know so far:

It was ran hot....until it died. Missing on 1 cyl, sounds like a valve knock on cyl #2. Bubbles in the puke tank as soon as I start it and it will overheat in less than 5 min at idle. Good oil pres so the lower end seems ok. Cracked head or blown head gasket land I assume. I'm going to recondition another head regardless and I need to know what years are interchangable with the `93. Also getting a new cam/lifters. Will port/polish do me any good or not?

Depends on how you plan to use the XJ. Port/polish typically helps the HP or higher rpm's better than the low. Port matching would help at all rpm's tho.

Sarge

This is just my opinon, but by time you get done spending the money and time with replacing all those parts why not just pull an engine from a junkyard with low miles. If ya look hard enough you can probaly find one for pretty cheap. Plus you got various years that would fit with maybe little to no modification. Just my two pennies though.

He's got an engine he knows mostly whats wrong. One from a junker could have the same problems or worse, ya just never know.

Sarge

Sarge said:

He's got an engine he knows mostly whats wrong. One from a junker could have the same problems or worse, ya just never know.

Sarge

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Yup, that's very true too. There's positives and negatives from both standpoints. The reason I suggested junkyard motor is because I have a 98ZJ motor in mine now. Had around 60k on it, and I have had no problems with it other than rear main seal. It's been very strong, and I've put about 20k on since it's been put in. But as stated above, your taking a risk either way.

Sarge said:

He's got an engine he knows mostly whats wrong. One from a junker could have the same problems or worse, ya just never know.

Sarge

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......which is why it's a good idea to pull a previously running junker 4.0 so that you know it's not completely trashed, take it home, strip it down completely, decide which bits are still reuseable, and consider building a budget stroker. :idea:
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1992 XJ Laredo 4-dr - 4.6L I6 HO Stroker - 177k miles - AX15, NP231, D35c, D30
258hp@4800rpm, 320lbft@3200rpm, 1/4 mile = [email protected], 0-60 = 5.9secs
Websites - Jeep 4.0 Performance, 4.6L Stroker Build-Up, Dino's Jeep Tricks