1990 XJ 4.0 swap - compatibility, goodies, etc.

My 1990 XJ's engine has lost compression on #6 (30psi) and my oil pressure isn't what it should be, so it's time for a rebuild. I'm looking for a donor engine so I can still drive my XJ if necessary while I build the new motor.

From what I have found on this forum, any XJ or ZJ engine through 1999 will work with my Renix as long as I retain my flex plate, intake/exhaust manifold, distributor, etc. Is this right?

Since I will be doing the rebuild myself, is there anything I should do (or shouldn't do) while I am at it?

I am considering boring it, aluminum pistons, bumping up the compression, cam, etc. Nothing too radical - just want a little more oomph. This vehicle is basically my daily driver with very little off-road activity. Any suggestions or advice would be appreciated. Thanks!

I suggest you trade your tired motor in as a core on a rebuilt engine from a reputable rebuilder. The mods you described will cost more than the improvements are worth for just a daily driver. You should be able to get a good rebuilt motor for about $1200 or less.

jeeperjohn said:

I suggest you trade your tired motor in as a core on a rebuilt engine from a reputable rebuilder. The mods you described will cost more than the improvements are worth for just a daily driver. You should be able to get a good rebuilt motor for about $1200 or less.

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For a "normal" person, that would be great advice. Unfortunately, I'm one of those "abnormal" people that look at an engine going south and think, "Cool, now I can build it up!" On my last Jeep (1978 CJ-7) I built a nitrous injected, fuel injected, 401 monster and I REALLY miss it!

I don't plan on spending a tenth of what I spent on that motor, but I don't want to sink a penny into a stock motor. I would rather spend a few extra $$$ and build something I like. At this point, I'm starting to lean towards building a stroker using a 258 crank and rods, but I'm gonna have to do some more research to see what all is involved.

A stroker will be a great project. Do plenty of research because it is not hard to make mistakes with a stroker build.

jeeperjohn said:

A stroker will be a great project. Do plenty of research because it is not hard to make mistakes with a stroker build.

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Do you know of any good source that may list exactly what parts are used, machining to be done, etc., etc., etc.?

For a 4.6 stoker
http://www.naxja.org/forum/showthread.php?t=1105534
For stoker tech visit jeepstrokers.com

PM Russ Pottenger, he is the socsl guru on jeep strokers.

jeeperjohn said:

PM Russ Pottenger, he is the socsl guru on jeep strokers.

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Apparently a lot of people PM Russ as his mailbox is full and I couldn't contact him...