Okay, various forces of nature, finance, and a heavy foot have led me to this point. I am rebuilding my 4banger. The block and head are in the shop right now. the head is getting a basic grind and two valves replaced (the ones that helped force this rebuild), overall in good shape. the block is getting bored out between .040 and .060 depending on how things go when they start working. Will obviously be putting in bew pistons, rings, bearings, etc.. My question comes down to the fact that if I am gonna have this thing bored out I at a minimum don't want to lose the little power I have in it, and would actaull like to gain some. I am looking at a 440 degree camshaft and probably a 4.0l throttle body. I am just not sure what I might need to do with fuel (if anything) will the stock computer be able to compensate for that much extra space? Should I look at bigger injectors? Adjustable MAP sensor? I am just not sure about some of this stuff. :rasta: :jeep:

I think Petco had 4 rebuilt HO hamsters for $99

Might want to look into that :flipoff2:


Seriously though, the 4.0 throttle body is probably a good idea. Not sure how much more the injectors can provide and if the computer is up to the task. Is there a performance chip available for the 4cyl?

Anybody know how many pounds the 4.0 and 4cyl injectors push?

if you can find a performance chip for the 4cyl you will amaze me, they don't seem to exist. Also forgot to mention I wil probably put an ignition on it too (msd) not sure what those injectors push, but I am currently working on that. I know they are the same as the XJ 2.5 but I don't know what those are either. Now back to "project pissed off hamster wheel"

my friend had a chip in his 4 cyl TJ
but he sent it back because it didnt have enough power

March issue of Jp did a four bangr special, They got a computer from Venom for almost $350, so yes four banger aftermarket computers are out there but for $350 I would rather get a v-8 from a junk yark.

Just had my 4 banger rebuilt after busting a piston. Other than a .020 over bore, didn't really do much else. Runs great. I didn't hear about the 440 cams until after the rebuild, but it sounds like a good move. The 4.0 TB is a definate plus from what I've read. I did have an Inertia ring added to the flywheel. I haven't noticed it much in daily driving, but can notice it when crawling. I did hav 4.88 gears added at the same time, so figuring out how much each part contribuited is difficult.

Robert

you might be better off buying a low milage take out from someone who dropped in the other 4 cylinders.

I've seen low milage (like less than 20k) for $400-500.

have looked for some pull-outs but the best I have seen is a 40K re-built for $700 plus shipping halfway accross the country, pretty much around the same price range I am looking at. And this way I get a bit more power. Is kinda fun anyway. :rasta: :roxy:

The same injectors are used on both the 4.0 and 2.5.
The injectors in the 6cly handle 40.33 cubic inches of volume. The volume in a stock 2.5 is 37.75 cu in, so the stock injector should be fine even with the added space.

Like mentioned earlier, venom makes a chip for $350. If you have a 97-up 2.5, there are catalogs that list JET chips for $250.