Cheap engine swap from a 4cyl to a ???

[Jdlefebure]

I'm just throwing out ideas to my dad and what would be more practical for an engine swap before I leave for school.

First off, I have a 98 wrangler SE with the 4cyl and 33" tires

1) I've thought about the 4.0 6cyl which would obviously be a step up and have enough power for 33's but I've heard it's a pain to swap this into an original 4cyl.

2) The "General" v8 swap.. 4/5 technicians from my work have told me a v8 swap would be smart due to more power and better gas mileage than what I'm getting right now (14ish with mixed driving) due to the v8 not having to work as hard on the highway.

3) The "Rich Person Swap" Cummins 3.9 diesel :D I know I couldn't afford one of these swaps but I'd love to have a diesel in it. Just thought I'd throw it out there for discussion ;)

4) What other cheap swaps are out there that would be fairly easy to drop in? The swap isn't going to happen right away necessarily but ideas always help. Planning to leave for school in the fall.

Opinions?

[Guest]

I love how we live next door, but I mete out most of my advice to you over the net. :)

Swapping is a huge consideration. The transmission, motor mounts, radiator, transfer case input shaft, driveshafts, computer all have to be changed.

1) I helped, but only on the motor mounts and a couple of small items. I can tell you from their experience that the NOBS group will probably never do another 2.5->4.0 swap again. Giant pain in the tail, and just as much work as a V8 swap. In the end you wind up with another "stock" jeep.

2) LS series V8 swaps are probably most economical in terms of adapters, etc. However, they aren't cheap, regardless of the engine. Furthermore, the best economy you're going to get is MAYBE 16 mpg. It's still a square. It takes a lot of miles to recover the cost of the swap with a 14% increase in economy. Consider you probably burn through $200/month in fuel or less, so you're saving at most $28/month in fuel. On a TIGHT swap budget that is somewhere in the range of 5 yrs to pay back. Bottom line, fuel economy is a crappy reason to swap engines.

3) 4BT swap would be awesome. Expensive, but awesome.

4) Nothing is as cheap as a GM V8, probably not even a factory offered engine swap.

If you're engine is in bad shape, just pick up a good 2.5L from someone swapping in a V8. If you're just after fuel economy and recover the lost power, put in 4.88 gears. Budget $800-$1000 for gears, which will be less than just about any engine swap you can conceive.

[Guest]

I think unless your planning on putting a carbed engine in there that the 4.0 is your best option. and luckily there are tons of build/swap threads detailing all the work involved in doing this, and im pretty sure theres a guy right now in the middle of doing the same thing on here. so i guess for simplistic reasons and to retain a mpfi engine id swap the 4.0

[Guest]

What about forced induction and a rebuilt 4 cyl long block?

Cost wise and work wise I bet it would be competitive with an engine swap.

Wally

[Guest]

Audioguy and tco10 are doing the 4.0 swap and probably wouldn't ever do it again.

FYI I have $2k in my turbo setup. I could probably have done it for $1500 or so if I knew anything about turbos and built it from scratch vs buying a kit. The kit was used, so at least I didn't pay the $4500 retail cost.

I don't know if I'd do another turbo. Yes, it runs well. Yes it's about as powerful as a V8. However, it is temperamental and doesn't provide any more torque off idle. Conversely, because it doesn't have more bottom end my drivetrain is probably more reliable.

Bottom line is that all options are going to have their deficiencies. Be prepared for all kinds of stuff to be wrong when it's done.

[JEEPINKC]

It's not all that hard to do the 4.0 swap. The key would be to have EVERYTHING available at the time of the swap. I would suggest a complete donor vehicle, like a totaled out vehicle or something like that.
I did a 4.0 into a CJ7 a few years back for my uncle and it was quite simple since I had the complete donor vehicle at my disposal. That being said, it is not the same as what you are wanting to do but similar in principle.

If you do the research you will find tons of info out there. I would do the GM LS swap if it was my Jeep. I've seen plenty of people getting mid to high 20's mpg with the proper setup and still have power to spare.

The CJ that I did is a weekend street cruiser and never goes off road. He wanted the reliability of fuel injection for trips to the mountains and the 1983 carb and emmission system was shot on it.

[audioguy1]

the only way I would ever do a 2.5 to 4.0 swap again is if the $$ was huge. Way to big of a pita for the $ for the power gain. Just spend the same amount, maybe a little more and go with a v8. the fuel mileage difference will pay for itself. and it's the same amount of work. if you'd like, you can come look at the one in my garage and I'll show you exactly everything involved and bring it into perspective. And i even have the donor rig sitting right next to the one we're working on.

[Jdlefebure]

the only way I would ever do a 2.5 to 4.0 swap again is if the $$ was huge. Way to big of a pita for the $ for the power gain. Just spend the same amount, maybe a little more and go with a v8. the fuel mileage difference will pay for itself. and it's the same amount of work. if you'd like, you can come look at the one in my garage and I'll show you exactly everything involved and bring it into perspective. And i even have the donor rig sitting right next to the one we're working on.

I might take you up on that offer this weekend if I can, I'm still learning and not a technician yet :D we can do the swap but time is also an issue of being out of a vehicle

[audioguy1]

get a hold of Tommy, he has my #

[Eatrocks]

I drive a LS swap and it’s nice and I get 20 to 26 MPG using the stock 6 speed and the stock 3:73 gears. I have done about 12 or 14 jeep V8 swaps and have sold 400 to 500 kits to do them The 4.0 6 is as costly or more than a Chevy v8 the 4bt is a nice swap but everyone I have seen worked nice but it was so much heavier that the swapper said they would never do it again You can easier got lost in the you need this and this to do this swap. By far the cheapest is a LS motor with the stock 5 speed a 5.3 from a 2002 to 2006 Chevy truck running can be had for 800 to 1400

[audioguy1]

I drive a LS swap and it’s nice and I get 20 to 26 MPG using the stock 6 speed and the stock 3:73 gears. I have done about 12 or 14 jeep V8 swaps and have sold 400 to 500 kits to do them The 4.0 6 is as costly or more than a Chevy v8 the 4bt is a nice swap but everyone I have seen worked nice but it was so much heavier that the swapper said they would never do it again You can easier got lost in the you need this and this to do this swap. By far the cheapest is a LS motor with the stock 5 speed a 5.3 from a 2002 to 2006 Chevy truck running can be had for 800 to 1400

I'll be picking your brain in the near future. Mine has nothing in it now and I'm leaning towards a 5.3/TH350/D300 and would like to talk to you about ideas and options

[cjmoon]

4bt's don't have to be expensive. but you have to give it some time and search. i found my truck for 2300 my buddy found his for 2000. scrap out of the truck was $1000 and sold about another $500 worth of parts off of it. engine with adapter for chevy manual ~$500. of course there was some work involved, then some upgrades but that happens with any motor. even in stock form there very good and different.

[Eatrocks]

I would use a 4l60 with the 231 unless your looking for something that only the 300 can do the adapter for the 350 to 300 is the same cost as the one for the 4l60 to the 231 or the 300 and the PCM to contral the 4l60 is aready there i even can walk you though the mods for the 5.3 harnness and no the 350 does not just bolt up to the 5.3

[Eatrocks]

I did not say the 4bt was costly just that it was not worth it in the long run I run a stock tranny and t case and rear diff plus the 4bt is so heavy the truck 5.3 is 50 lbs lighter that the I6 I have seen some very nice 4bts

[audioguy1]

And thats the reason I want to talk to you when I get closer to doing mine. No more threadjack. Back on subject