2.5 vs. 4.0

I agree with stroking it, 505 performance has a kit for that or you could search jeep 4.0L stroker kit on google rock crawler.com has a great right up about using some parts for the 4.2 in the 4.0L to get a 4.5 and make alot more power.
 
Yeah google it there bound to have stormer kits for it, sorry about mentioning the 4.0 stroker and that forgot you had a 2.5, I would for sure try to get as much power as I could out of it if I was you, and stroking it will do just that and it's fairly cheap.
 
I just bored out the bottom of my 4.0L TB on my 2.5L engine. The bottom only. The stock 4.0L TB is 60mm on top and 55mm on bottom side. So little by little I bored the bottom to 57mm. Does not sound like much, but it did make a nice difference. I was good with the swap only, but just had to try to get a lil more. Scary because the 2.5L is sensitve engine. To much air in or out you loose torque, not enough air in or spark you get no horse power gain. Anyway it did work out just fine. Right on the border line of almost going to big for my current mods. I gained a much smoother idle, a real nice smooth crawl speed, and quicker off line response. Good top speed. I did notice a tiny, tiny bit of torque loss at top end. But am still good nothing to complain about. I am gonna consider a electric fan, who knows.
 
What I am missing a lil is just that snap or jerk when I step on pedal further down, when I am already cruising at highway speeds. I could say in a way its just more suttle. Its like I am looking for it when going up hills. Still climbs just smoother. The power is there but just smoother. Its not really a bad thing. Just a different feeling. A good thing. I tell you what thou, It really takes off instantly, and climbs quickly to higher speeds. Highly recomended. Just saying its a different flavor. Nice thou. Maybe I am repeating myself. No regrets. It idles really smooth, has a nice crawl speed. Power on tap is a smooth response. Like I said before just have to fine tune my adjustable air slide on my cold air intake thats all.
 

I've never known a 2.5L to have any snap or jerk at highway speeds, in any of the numerous configurations I've ran. I appreciate you trying to articulate what you have perceived though.
 
Bounty hunter hes saying he doesn't have a jerk when he steps on the fads off the line and that its smooth at highway speeds, he isn't saying there's a jerk at highway speeds, because he's smart enough to know that wouldn't make sense. You just read it wrong.
 
I have a 94 yj 2.5, and I wonderin people were saying with 33's I should put 4.10 gears in it, what is your recommendations
 

Yj1994 said:
I have a 94 yj 2.5, and I wonderin people were saying with 33's I should put 4.10 gears in it, what is your recommendations

4.10s would work if you had a strAight six but for the four banger 4.88 would be good you should have 4.10s in it right now
 
You know this was the first time I did not reset my rigs main brain by disconnecting battery. Why I did not do it, I guess I though it would be to little of a change. But today after running it again, about 4th time since swap, I believe the changes are being pickup by the main brain. I tell you she is faster, smoother idle, smoother take off, and when I say take off, its fast of the line, she contiues to climb steady and smooth to high speeds, holds speeds better with less throttle. Cruising on highway seems to take less effort on gas pedal. Its all good. Maybe all am saying its has different charicteristics than before. I think my rig was fast before and it was. Maybe before the swap and bore it was a lil to jerky for drivability and control. She is now smooth, and easy, and climbs quickly without being jerky. Maybe I am use to that jolt which might be a fine line between torque and drivability. Maybe the change is me getting use to the pleasent gains. It just feels really comfortable, to have a smooth instant response, NICE. Again when I say instant its power on tap. Just filled her up today, will keep tabs on gas mileage. I know its hard to drive normal, she feels so good. I like to go fast. To imagine the bore only went from 55mm to 57mm. Good results, in all around driving. Hmm I can only imagine what even a bigger bore will do.
 

Yeah i Got the 2.5L. in my jeep, it's not made for speed, but it does great in the mud and hills because my jeep is really low geared.
 
Not trying to brag or anything but I finally got my little 4 banger built for more torque and speed. Ready to go anywhere. Just saying that little engine has the potentail to do both. Dont give up on it, or settle for just one when you can have both. Well the choice is yours ofcourse for your own needs. Happy Wheeling.
 
Here is my little 4 Banger, she is a daily driver and she is all I have right now. Gotta baby her.
MBourjeep-1.jpg
 
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Bigger is better? ^^
 
whats the bottom line on replacing the fan blade with an electric fan on the 2.5? I read somewhere that you get a pretty good increase in power doing that?
 
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