so i have roughly over 255,000 miles on this little 4banger. in the next month or so, i plan to completely rip open the motor, and start fresh. im looking for some advice and comments on companys that build good overhaul kits for this engine. perferably maybe something in the range of more performance, more torque. been looking around and havent found much. any info will be helpful, thnxs
Forget more power and more torque...it won't happen. There have been some who worked out a turbo-charger rig, but I don't think that's where you are headed. Generally, a 2.5 is always going to be a 2.5. It's a good engine, I drive one every day.
Motor Mounts, Motor Mount Lifts (MML), and Engine Brackets for Jeep 100% HANDCRAFTED IN AMERICA
Brown Dog Mounts and Engine Brackets (Serial Number 1)
4.5" Superlift SL
35" GoodYear Mud Terrains
Conteract Balancing Beads
Bulldog front bumper
Best Top seats
"Family" roll bar
25 foot 1/2" log chain
No Top, No Doors (Best Top Safari)
thnxs, so no info at least on doing a overhaul job, which companys sell the parts, been thinking alot about a turbo sawp, but thats another thread. JPmagazine has an article about upgradeing to a turbo.
i just want a good overhaul kit, if possible.
The link I posted has a group of Jeepers that are dedicated to the 2.5L engine. You will get a bunch of info there. Are you in Costa Rica or L.A.? A long block would be easier than going through a rebuild and an upgrade to a 4.0L or a Chevy motor would make more financial sense if you are looking for big performance upgrade differences. I am happy with my 2.5L except I have no 5th gear with the 32.5" tires.
I agree with brown dog, dont waste a bunch of money on it. They are great little engines that do exactly what they were designed to do but it will never be a powerhouse. Still there are a few things you can do to get a little more torque out of it after your rebuild. Make sure you have the head rebuilt by someone competent. Thats where the power is made. Have them shave enough off the head to bump you up a point on compression. You will likely need to run a higher octane fuel, but you probably have leaded fuels in Costa rica anyway. You get roughly a 10% increase in torque output for every point of compression. I.e. 10:1 versus 9:1 or whatever. But you cant go to crazy here without pissing off the computer. Port matching the head and intake to the gaskets is always good for a little bit of flow improvement. These mods are cheap and easy. You can buy a performance cam for it if you want but for the money vs improvement its not worth it. Roller rockers are always a good idea. They are a little pricey but can be reused on the next rebuild. They give a reduction in friction and more importantly dont wear like the factory arms giving you accurate lift. Youd be amazed how much has worn off the stock arms. I still wouldnt really want to drop that much money in that motor though. YMMV
Your limited slip differential sucks.
I realize this is an old thread, but I just found it looking for info on overhauling the 2.5L engine. I also live in CR, and was wondering where you are at... I live in Santa Ana. Anyway, did you do the overhaul after all? How did it come out? Since the gasoline here starts out at 91 octanes (unlike the US, where regular is 87) I am considering going up to 10.4 or so compression ratio, but was wondering if you had any experience with this.
'94 YJ 2.5L with 4" RE lift, Adv. Ad. SYE, Woody Shaft, Superwinch EPi9.0, 62mm TB, FoMoCo e-Fan, SD30 and SD35 w/ARB-4.88, 165A alt., 4 KC aux lights, Aluminum Rad with BRX hoses, 33" BFG KM2 on 15" AR wheels, Sony sound system, Pavement Ends Hardtop, Bosch 19# Injector, Safari Snorkel, 95.5 Brakes