Jp magazine did an article on this, in the March 2007 edition on page 94 "Bag the Banger" They simulated one stroked 2.5L and it "wound up making something like 20 hp over the stock one at a ridiculously high rpm, low end torque was worse than factory at speeds below 4,000rpm also all the parts would be custom with mostly mallory metal to keep it from shaking itself to death", by the time he was done it was in the $4,000 - $5,000 dollar range. "The head doesnt really support any decent power levels anyway." They reccomended a turbocharger instead.
1992 Cherokee Laredo 4.0 L6, Aw4, Dana 30/35, Np242, 201k
Crower p/n 44243 Camshaft, Camsaver High Oiler Lifters, He Pistons .030 Over, Decked Block and MIlled Cylinder Head. Melling High Volume Oil Pump
Flowmaster Super 40/ Cat and Tailpipe Delete, Apn Header, Homebrew Bored Throttle Body, Rustys Cold Air Intake with Spacer
Here is some issues with the 2.5;
PROS; 350 lbs vs. 500+ for the 4.0
head work is a good bang for the buck
cams are available
engine compartment room is less of a problem
CONS; 9.3 compresion ratio stock inhibits boost level without a piston change
final power level is going to be about 45 % less than =$ spent on a 4.0
SUMMARY; If one starts a project with another engine on a stand it will be a ton easier. Given that, it can be done in the Jeep,but I would not recomend it. It would be a limited approach ending up with somewhere in the 180 hp range. This is without pulling the engine apart. I have heard reports of 200 hp being achieved and find that sceptical and preignition would be a big/constant issue! Now, If the engine is out and/or time is not a factor. Lower comp pistons, cam and some minor head work could give a big bang for the buck. Only to the effect of somewhere in the 220 to 240 hp range. I say only in respect to the 4.0 potential is a good bit higher. Although the 4.0 weight balance is going to be heavier on the front end(150+ lbs) and cooling issues will need to be adressed. Not so much on a 2.5 due to a 4.0 high capacity radiator is commonly available if not already there ! Is it worth it ? I think so if 220/240 hp is good enough for the need. It goes back to an old saying "Is the journey the goal or the end" This would be a rig with great everyday performance/mpg if kept light. Say less than 3000 lbs. It can be done. If a 6" lift is in mind and lots of armor or hittin' 13's at the strip, then just plain "forget about it" ,,,,,,ain't gonna make no one happy !!!!!!!!!!!!!!!!!!!!
White 01 WJ (stock 4.7 limited)
White 08 MK Patriot (minor mods) -SOLD-
Looking for a White (ultralite?) project Jeep -FOUND-
White 09 JK "X"
An all the thread stalking I have been doing over the years, I haven't seen it done.
Just googled it with little results, although I have seen some people mention that they
have seen a 2.7L done. But, that's one of those "a friend has a friend that knows a guy
that saw a guy on a forum do it".
im new here, i wouldve made a new thread but wasnt sure how to??
anyway i just have a question regarding all the 2.5 posts...
why do ppl say its so slow and under powered?
Now i own a Dakota, not a Jeep. but since its the same engine and its more
popular in the jeeps i figured this would be the better site. I know the jeep and the dakota
are two total different machines but for a 4 banger truck it moves great. the mods i have done include
cold air intake, headers, downpipe, flowmaster 40, electric fan, and lower temp thermostat. i also have a
4.0 TB i have not put on yet and a set of perf. plugs, wires, dist. etc. Its also fairly peppy.
some of the vehicles i have won against in a race are 79 400 ranger, 97 dodge ram, 04 chrysler 300, 94 s10,
honda civic, etc. i also suprisingly won against my friends 09 warrior 350 4wheeler, me and him both thought
i would get smoked. I did not over exhagerate, the cloesest of them all was the 300 chrysler because i only can
win until about 80mph(when i shift to 4th he passes). anyway point of the post is im just tryin to figure
out why ppl dog the 2.5l so much?? and if anyone has any ideas or tips for my truck feel free to let me know. thanks