Engine swaps

[RockcrawlingTJ]

We just picked up my wife's 4-door Rubi a few days ago. I knew the engine was not going to be up to my standards, but just how bad it was was not apparent until I actually drove it. Heck, you need a running start if you want to pass somebody! I already miss the straight six of old...

Anyway, I know Burnsville Offroad is doing the Hemi swaps, and Hesco has a supercharger for the 3.8L. What are other options? Anyone swap other engines into the rigs yet? I knew a lot of guys with 4.3 Vortec swaps, others with GM 350 swaps, and a few with the 5.0L Ford swaps. Does Painless or the like have wiring harnesses for the swaps yet? What are issues with the electronics that have been run into? Bolt pattern matching up with the tranny? This is a 6-speed by the way - will it hold the extra power?

Thanks for the direction -
Justin

[Volley]

The engine is no race horse but it does get better the more it is broken in.

[twinturbostang]

It seemes like the 4 door guys are all the ones who dont like the motor. In the 2dr its just not all that bad. I mean its no race car, but its not as slow as all you 4dr guys seem to think. So i guess that extra lbs is just to much for the little v6.

AEV has The HEMI Upgrade availability for Late 2007

[RockcrawlingTJ]

LOL When you get passed by an '89 Corolla driven by an old lady, I think there's a problem with the engine. Haha...

I am giving many options serious consideration. The Hesco charger is a nice option, but spending $4600 for about 90 more horse when I can spend around the same amount and drop in a higher horse engine seems a bit more logical to me.

So again, anyone else have experience with other engines besides the Hemi?

JB


It seemes like the 4 door guys are all the ones who dont like the motor. In the 2dr its just not all that bad. I mean its no race car, but its not as slow as all you 4dr guys seem to think. So i guess that extra lbs is just to much for the little v6.

AEV has The HEMI Upgrade availability for Late 2007

[Jake_Blues]

I just don't get it. I have no problems with my JK Unlimited's motor. It is bone stock, no mods. I'm running 35s so my gearing is rather high, and I'm above 5,000 feet altitude all the time, which means I'm losing like 10% torque versus sea-level guys already.

I have no problems accelerating, driving up grades, 4-wheeling at 11,000 feet, etc. As long as you keep the engine in its happy place (2,500 RPMs or above), it works just fine.

I think most of the people who complain about the lack of power in the JK are either driving it wrong, or are used to grossly over-powered vehicles. Try driving an 85hp FJ-40 for a while, then get back in your JK :D

-E

[duneslider]

I also think the engine is pretty good. I smoke TJ's all day long. Even with 33" mudders. This engine does occasionally have a hesitation but I don't think it is the engine, I think the drive by wire is the cause. Once good programmer comes out I think it will really wake these up.

I am certainly not getting passed by 89 corollas with old ladies driving!

Bryan

[ccdjeep]

Man, don't take this the wrong way, but it sounds like you have more money than sense. You just bought the thing and already want to swap engines... :nuts:

Give the 3.7L a little time to break in. It is VERY sluggish for the first thousand miles in my opinion. Maybe a little more for some folks. After the break in if it still ain't chuggin to your liking, add a CAI, exhaust and chip or progammer.
I had a V8 CJ-7 and the JK doesn't have near the power my 304 did but the 3.7L is no slouch either, IMO.

But if your still gung ho about it, I think SargeantROCK on here has the HEMI conversion. Look for his threads on it.

[BigHugh54]

Just give it a little time. When I drove mine home I was very disapointed, but then at about 600 miles I started to noticed a little more pep-in the step. I'm at 1600 now and it's good to go man. Be patient.......:yup:

[PUDDIN]

LOL When you get passed by an '89 Corolla driven by an old lady, I think there's a problem with the engine. Haha...

I am giving many options serious consideration. The Hesco charger is a nice option, but spending $4600 for about 90 more horse when I can spend around the same amount and drop in a higher horse engine seems a bit more logical to me.

So again, anyone else have experience with other engines besides the Hemi?

JB

Sound like to me you need drive one of your Mustangs if you feel the need for speed. We have not had any problems with our 4-door JK even on a 1400 mile trip.:toung:

[tjdUSCG]

Eff it, drop a big block in that mo' fo'. Hell, put a jet booster on the back like the bat mobile, that's what I'd do.

[RockcrawlingTJ]

Jake:
We are in the same area (and if you haven't figured this out, also on CO4x4). Care to take me for a ride so I can compare?

For the others - the post was created to find out about viable engine swaps for the jeep. I don't need your opinions or statements that I have too much money and not enough sense, or those telling me to just drive it. Give me something constructive - I am not new to the jeep game, I have had my own 4x4 shop where I specialized in TJ's and YJ's and I still do quite a bit of work for a chosen few. This is the first experience with a JK so I came to where I thought I might get some viable information and first-hand knowledge. Granted, you may not have seen any of my other posts where I spelled this out. I didn't think I would have to spell that out in this type of post. I guess I assumed too much.

For those, like Jake, stating they do not have these issues or the sense of not being able to get out of its own way - that IS constructive because I have heard the ESP can be touchy and show these types of symptoms. Perhaps I need to have the jeep flashed, although that was supposedly done before I took delivery.


I just don't get it. I have no problems with my JK Unlimited's motor. It is bone stock, no mods. I'm running 35s so my gearing is rather high, and I'm above 5,000 feet altitude all the time, which means I'm losing like 10% torque versus sea-level guys already.

I have no problems accelerating, driving up grades, 4-wheeling at 11,000 feet, etc. As long as you keep the engine in its happy place (2,500 RPMs or above), it works just fine.

I think most of the people who complain about the lack of power in the JK are either driving it wrong, or are used to grossly over-powered vehicles. Try driving an 85hp FJ-40 for a while, then get back in your JK :D

-E

[BigJerm]

i think the three options have been stated. Either you get several NA mods (intake, headers, exhaust, tuner), you go the FI route with the SC set up or the Hemi swap.

[JeepDog]

I think Burnsville Offroad said the 4.7 V8 is a nice swap. Since I think its more of a drop in plug and play setup.....That's a pretty good motor too....

I have no problems with the 3.8 since I sorta know where to drive in the power band...but if I could have a 4.7 V8 in it I would take it....although I would rather have a Turbo Diesel...:eek2:

[Rubidon]

I think Burnsville Offroad said the 4.7 V8 is a nice swap. Since I think its more of a drop in plug and play setup.....That's a pretty good motor too....

I have no problems with the 3.8 since I sorta know where to drive in the power band...but if I could have a 4.7 V8 in it I would take it....although I would rather have a Turbo Diesel...:eek2:

I have (my wife has) A 2005 Grand Cheroke with the 4.7, that is a great motor and all though I have no issues with my 3.8.........4.7 would be pretty sweet. I will say I drilled some holes in the air box and dropped in a K&N and It feels a bit more responsive...........but still no 4.7L:yup:

[07 RBY]

I agree that the 4.7 is a great motor. If you want real power and can afford it, the 5.7 HEMI is "Da Bomb". I have a mildly modified one in my Magnum, and it gets down right scary at times. I got my Rubi with 3875 miles on it and thought it was grossly underpowered. I now have 6047 miles and it feels a bit stronger.

[JeepDog]

Yeah I have heard the 4.7's are just really good. I heard awhile back that a 4.7 Magnum will spank the ole 5.9 Magnum RT Dakota...

Nevertheless, The reason the 4.7 would make a great swap is apparently due to the electronics and fuel system or something like that. Personally i don't NEED a 345-420hp Wrangler....But I would LIKE a nice 250-300hp one....I would think the fuel economy would go up. Regardless I have the 3.8 and it gets the job done....I could always buy one of those Hesco's Blowers...Rotrex setup to get me where the new 4.7 is rated...300hp/330lbft.