Buy or build my 2.5 ?

[piratessoul]

I want more power. I don't want to stop driving my '95 YJ to do the rebuild. What I want to know is...

1. Where can I buy a quality performance 2.5 crate motor?

2. What mods are necessary to get maximum performance out of a 2.5 if I decide to buy a used one, and do it myself?

All input is appreciated.

 

[xt master]

Not sure if it is cost effective to get the HP out of the 2.5l,but if you want there are always turbo's or blowers available.You also have the normal things like cam,larger tb,bigger jets.Bored,ported,polished.

 

[piratessoul]

I heard (somewhere) that 2.5's can be bored out and, with a cam, can be quite remarkable. Just can't remember where I heard/read that.

 

[bobcat481]

Wait for Steelheadz to come along. He's done alot of the mentiond above, besides turbos and such.

 

[ljrubitm]

JEEP 2.5 LITER ENGINE (1991 - 2001) | JEEP 2.5L CRATE ENGINES & MOTORS

I realy don't know how much it would be to rebuild a engine, but their price for a engine is $1,150-$ 449 core- 7/70K warranty.

 

[jfrabat]

I have heard of them bored out 60 over... I have also seen a couple with blowers and turbos. In my opinion, the blower is the better option for wheeling (more linear accellaration and no lag), but it is also the most expensive.

In mine, I run a Mopar Performance Cam (450 lift 256 duration), Performance Distribuitor system (rotor, cap, LiveWires, Screaming Demon Coil), plugs gapped at .060", bored out 4.0L TB (62mm), 62mm TB spacer, Fram AirHogs filter, snorkel (works as CAI and RamAir), 19# Ford Design II injectors with and adjustable FPR set at 46PSI, eFan (with 160A alternator and DC Control box), Magnaflow high flow cat and Borla CatBack. I also run 4.88 gears to turn 33" BFG MT KM2's.

Offroad, mine behaves fairly well, and holds its own with the I6's. But on the highway, I still feel it needs a bit more power. I think 5.13 gears would be the ticket, as when I ran the 4.88's with 31's it was really in the range of RPM's that the 2.5L loves to be in, but, of course, that means 2 new axles, and that aint happening anytime soon...

I am sure if I rebuilt mine, I would gain a lot of power (it does have 135K miles on it), and I do plan to overhaul it sometime in the short to mid-term. Hopefully, this will increase power enough for me, but if not, I think a blower is going in on the long term...

 

[piratessoul]

I really appreciate the info. I think I'll do some more research, pick up a used 2.5, and build it to the maximum specs. I think you're right about the gear ratio, though. It's just not going to be a highway machine. But hey, if I wanted speed I'd build a '71 RT Charger!

Thanks!

 

[jfrabat]

I really appreciate the info. I think I'll do some more research, pick up a used 2.5, and build it to the maximum specs.

I think that is wise to do...

I think you're right about the gear ratio, though. It's just not going to be a highway machine. But hey, if I wanted speed I'd build a '71 RT Charger!

Your perspective tends to change when you have to drive it for 16 hours straight... I take mine from Panama to Costa Rica and back a couple of times a year (about a 600 mile roadtrip each way). Also, the lower gears will give you more low end torque when wheeling, which is nice to have...

 

[JohnnyO]

Jasper Engines, but they're kinda pricey.