Liberty V8

Jeepman56 · **Posted:** Sun Oct 14, 2007 1:45 pm

Just a curious question really, has anyone ever looked into dropping a V8 into a KJ? Do they even make ones that would fit in the engine compartment?

KJ4ME · **Posted:** Sun Oct 14, 2007 2:44 pm

i think the 4.7 liter V8 fits, im not sure if anybody has successfully done it but i strongly believe that i read on one of the jeep forums that the 4.7 can fit with some modifications. now, i didnt look to see if they used the same transmission or any of that stuff.

Alak · **Posted:** Sun Oct 14, 2007 3:21 pm

As luck would have it, the 3.7L and the 4.7L are the same engine, minus two cylinders. Or at least thats what my Mopar mechanic cousin says. He also says to stay away from the 5.9L, as its not a well built engine (versus the 360 of old).

Jeepman56 · **Posted:** Sun Oct 14, 2007 3:29 pm

Cool thanks guys.

Donnie · **Posted:** Sun Oct 14, 2007 3:40 pm

Don't quote me on any of this:

The 4.7 will fit, but will require new engine mounts and a new harness. It will mate up to the tranny if you have the 45RFE like I do, which is commonly found in the 02-03 models. This is the same tranny that the 4.7 uses in the rams; otherwise more recent libertys have shifted to a more car-like tranny for better mileage and shift points. This newer tranny won't be able to handle the power of the 4.7 either.

Now, if the 4.7l fits I don't see why a 5.7 won't. The 5.7 is shorter (and wider) than the 4.7. Then of course we come into power handling problems, but we'll worry about that when we see it.

I have the funds for the swap, I just don't have the balls to be quite honest. Void the warranty, and with an engine at 46,000 it doesn't make much sense. Maybe when the Jeep becomes my winter mobile.

KJ4ME · **Posted:** Sun Oct 14, 2007 3:45 pm

i like the 3.7. has good power, fairly quiet, above average gas mileage, i like it a bunch. a v8 seems like it would be even more fun!

tjkj2002 · **Posted:** Sun Oct 14, 2007 4:21 pm

Quote:

The 4.7 will fit, but will require new engine mounts and a new harness. It will mate up to the tranny if you have the 45RFE like I do, which is commonly found in the 02-03 models. This is the same tranny that the 4.7 uses in the rams; otherwise more recent libertys have shifted to a more car-like tranny for better mileage and shift points. This newer tranny won't be able to handle the power of the 4.7 either.

Now, if the 4.7l fits I don't see why a 5.7 won't. The 5.7 is shorter (and wider) than the 4.7. Then of course we come into power handling problems, but we'll worry about that when we see it.

No motor mount swap needed,the 4.7 uses the same mounts and they are located in the same spot(just like the Chevy 5.7 and 4.3).The new harness and ECM is correct though.As far as the 5.7 HEMI,that engine is huge compared to the 4.7,it would fit but the amount of metal you would have to cut would severly weaken the unibody and make it useless besides a show vehicle.

Give me a year or so after my SFA and I plan on putting in a 4.7,not built up(only headers and a CAI intake).Just swapping in a stock 4.7 will gain me mileage due to my KJ's wieght.Though I'm looking at the '08+ Grands that will have a 340+HP 4.7,need to what till '09 for some cheap wrecked '08's to be available.

Donnie · **Posted:** Sun Oct 14, 2007 5:56 pm

tjkj2002 wrote:

Quote:

The 4.7 will fit, but will require new engine mounts and a new harness. It will mate up to the tranny if you have the 45RFE like I do, which is commonly found in the 02-03 models. This is the same tranny that the 4.7 uses in the rams; otherwise more recent libertys have shifted to a more car-like tranny for better mileage and shift points. This newer tranny won't be able to handle the power of the 4.7 either.

Now, if the 4.7l fits I don't see why a 5.7 won't. The 5.7 is shorter (and wider) than the 4.7. Then of course we come into power handling problems, but we'll worry about that when we see it.

No motor mount swap needed,the 4.7 uses the same mounts and they are located in the same spot(just like the Chevy 5.7 and 4.3).

Wow, I never knew that!. So basically we're looking at the harness, reflashed ecu, air filter and headers back? Will the a/c and everything bolt over? You're right about the mileage, I think any lifted KJ would benefit from the V8, my 6 seems to struggle on the freeway.

tjkj2002 · **Posted:** Sun Oct 14, 2007 7:48 pm

Donnie wrote:

tjkj2002 wrote:

Quote:

The 4.7 will fit, but will require new engine mounts and a new harness. It will mate up to the tranny if you have the 45RFE like I do, which is commonly found in the 02-03 models. This is the same tranny that the 4.7 uses in the rams; otherwise more recent libertys have shifted to a more car-like tranny for better mileage and shift points. This newer tranny won't be able to handle the power of the 4.7 either.

Now, if the 4.7l fits I don't see why a 5.7 won't. The 5.7 is shorter (and wider) than the 4.7. Then of course we come into power handling problems, but we'll worry about that when we see it.

No motor mount swap needed,the 4.7 uses the same mounts and they are located in the same spot(just like the Chevy 5.7 and 4.3).

Wow, I never knew that!. So basically we're looking at the harness, reflashed ecu, air filter and headers back? Will the a/c and everything bolt over? You're right about the mileage, I think any lifted KJ would benefit from the V8, my 6 seems to struggle on the freeway.

All accessories will transfer.A custom raditor and a thinner electric fan or smaller dual fans will be needed,also the raditor will need to be moved forward about a 1/2"-1" depending on fan arrangement.You will need the whole new ECU from a vehicle(for me '99-'03 Grand works best) with a 4.7,need the extra pins in the connectors for the other 2 injectors and plugs.

Donnie · **Posted:** Sun Oct 14, 2007 8:24 pm

tjkj2002 wrote:

Donnie wrote:

tjkj2002 wrote:

Quote:

The 4.7 will fit, but will require new engine mounts and a new harness. It will mate up to the tranny if you have the 45RFE like I do, which is commonly found in the 02-03 models. This is the same tranny that the 4.7 uses in the rams; otherwise more recent libertys have shifted to a more car-like tranny for better mileage and shift points. This newer tranny won't be able to handle the power of the 4.7 either.

Now, if the 4.7l fits I don't see why a 5.7 won't. The 5.7 is shorter (and wider) than the 4.7. Then of course we come into power handling problems, but we'll worry about that when we see it.

No motor mount swap needed,the 4.7 uses the same mounts and they are located in the same spot(just like the Chevy 5.7 and 4.3).

Wow, I never knew that!. So basically we're looking at the harness, reflashed ecu, air filter and headers back? Will the a/c and everything bolt over? You're right about the mileage, I think any lifted KJ would benefit from the V8, my 6 seems to struggle on the freeway.

need the extra pins in the connectors for the other 2 injectors and plugs.

Would this be the harness?

tjkj2002 · **Posted:** Sun Oct 14, 2007 8:29 pm

Donnie wrote:

tjkj2002 wrote:

Donnie wrote:

tjkj2002 wrote:

Quote:

The 4.7 will fit, but will require new engine mounts and a new harness. It will mate up to the tranny if you have the 45RFE like I do, which is commonly found in the 02-03 models. This is the same tranny that the 4.7 uses in the rams; otherwise more recent libertys have shifted to a more car-like tranny for better mileage and shift points. This newer tranny won't be able to handle the power of the 4.7 either.

Now, if the 4.7l fits I don't see why a 5.7 won't. The 5.7 is shorter (and wider) than the 4.7. Then of course we come into power handling problems, but we'll worry about that when we see it.

No motor mount swap needed,the 4.7 uses the same mounts and they are located in the same spot(just like the Chevy 5.7 and 4.3).

Wow, I never knew that!. So basically we're looking at the harness, reflashed ecu, air filter and headers back? Will the a/c and everything bolt over? You're right about the mileage, I think any lifted KJ would benefit from the V8, my 6 seems to struggle on the freeway.

need the extra pins in the connectors for the other 2 injectors and plugs.

Would this be the harness?

You would need the harness also,along with the V-8 ECM.That's why I'm getting a wrecked Grand(heavy rear end wreck) so I can get all the litttle thing from it.The wiring harness is the big one,they ain't cheap(oh about $1000-$3000).

Donnie · **Posted:** Sun Oct 14, 2007 9:13 pm

tjkj2002 wrote:

Donnie wrote:

tjkj2002 wrote:

Donnie wrote:

tjkj2002 wrote:

Quote:

The 4.7 will fit, but will require new engine mounts and a new harness. It will mate up to the tranny if you have the 45RFE like I do, which is commonly found in the 02-03 models. This is the same tranny that the 4.7 uses in the rams; otherwise more recent libertys have shifted to a more car-like tranny for better mileage and shift points. This newer tranny won't be able to handle the power of the 4.7 either.

Now, if the 4.7l fits I don't see why a 5.7 won't. The 5.7 is shorter (and wider) than the 4.7. Then of course we come into power handling problems, but we'll worry about that when we see it.

No motor mount swap needed,the 4.7 uses the same mounts and they are located in the same spot(just like the Chevy 5.7 and 4.3).

Wow, I never knew that!. So basically we're looking at the harness, reflashed ecu, air filter and headers back? Will the a/c and everything bolt over? You're right about the mileage, I think any lifted KJ would benefit from the V8, my 6 seems to struggle on the freeway.

need the extra pins in the connectors for the other 2 injectors and plugs.

Would this be the harness?

You would need the harness also,along with the V-8 ECM.That's why I'm getting a wrecked Grand(heavy rear end wreck) so I can get all the litttle thing from it.The wiring harness is the big one,they ain't cheap(oh about $1000-$3000).

They're really that much?!? I remember I was going to do a 4.3 to 5.3 swap in my Chevy RCSB and they were only about 60 used, like this one:

http://cgi.ebay.com/ebaymotors/Engine-w ... dZViewItem

DarbyWalters · **Posted:** Sun Oct 14, 2007 10:04 pm

DC actually put one in but it wouldn't pass the "crach test"...engine protruded into the passenger department...that is the story back from 2003. You got to figure that the bay is long enuff since the 2.8L Diesel I4 fits...it would be as long as a 5.6L V8 for practible purposes.

djformi · **Posted:** Mon Oct 15, 2007 7:54 am

so if i was to take my engine and everything else needed out of my 4.7 00' dakota itd work?

Blue KJ in PA · **Posted:** Mon Oct 15, 2007 9:29 am

Years ago there was a rumored 318 dropped in to a KJ in the Poconos...I vaguely remember some one claiming to have seen it...might have been Al.

Jeepman56 · **Posted:** Mon Oct 15, 2007 10:50 am

WOW! I am unlifted so the V6 is doing just fine, but a V8! :twisted:

I think I would be in some trouble.

jeepgirl0385 · **Posted:** Tue Oct 16, 2007 1:20 pm

*Sorry to interrupt regularly scheduled programming*

KJ4ME wrote:

i like the 3.7. has good power, fairly quiet, above average gas mileage, i like it a bunch. a v8 seems like it would be even more fun!

I'm not trying to be rude, but have you driven the 3.7? It has no power, and absolutely abismal gas mileage. It is quiet though, which is nice.

The Liberty is a relatively small SUV, it is similar to a Rav 4, or a CR-V (well size wise, not capability wise). If you look at fueleconomy.gov and look at the ratings on these similarly sized SUVs, you will see that the Liberty is one of the worst.

However, I do love my Liberty. I did buy it to commute, but I wanted to get there in all weathers, and I know my Jeep will, unlike the other "SUVs" that are more crossover than anything. I also like to know if I need to, I can tow 5000lbs.

Maybe it is the gearing that makes it feel so slow, but I got my butt whipped by my bf in a Geo Metro ("drag racing" to 50mph(speed limit) from a stoplight). The only reason I won was because the tranny in the Metro is bad so he missed 2nd, but he was still right there.

It really sucks how a 300hp high performance Camaro SS can get 28mpg highway, but yet a little 210hp Jeep can't even pull 20mpg unless it is all highway and you baby it. It's not like the Jeep drives around at high RPMs, it cruises on the highway around 2000rpms or so, and i know other cars have to work harder.

It's a shame the diesal was discontinued, as I am sure that has plenty of power, and diesels are easier to modify to get even more power, at least in the truck market with devices like the BullyDog.

Don't get me wrong, I do love my Liberty and don't plan on trading it (and I hate the new Liberties, in fact I dislike all the new Jeeps except the Wrangler). But Chrysler didn't take the time to build a good motor/tranny/gearing combo.

*now back to your regularly scheduled programming*

Donnie · **Posted:** Tue Oct 16, 2007 1:38 pm

jeepgirl0385 wrote:

*Sorry to interrupt regularly scheduled programming*

KJ4ME wrote:

i like the 3.7. has good power, fairly quiet, above average gas mileage, i like it a bunch. a v8 seems like it would be even more fun!

I'm not trying to be rude, but have you driven the 3.7? It has no power, and absolutely abismal gas mileage. It is quiet though, which is nice.

The Liberty is a relatively small SUV, it is similar to a Rav 4, or a CR-V (well size wise, not capability wise). If you look at fueleconomy.gov and look at the ratings on these similarly sized SUVs, you will see that the Liberty is one of the worst.

However, I do love my Liberty. I did buy it to commute, but I wanted to get there in all weathers, and I know my Jeep will, unlike the other "SUVs" that are more crossover than anything. I also like to know if I need to, I can tow 5000lbs.

Maybe it is the gearing that makes it feel so slow, but I got my butt whipped by my bf in a Geo Metro ("drag racing" to 50mph(speed limit) from a stoplight). The only reason I won was because the tranny in the Metro is bad so he missed 2nd, but he was still right there.

It really sucks how a 300hp high performance Camaro SS can get 28mpg highway, but yet a little 210hp Jeep can't even pull 20mpg unless it is all highway and you baby it. It's not like the Jeep drives around at high RPMs, it cruises on the highway around 2000rpms or so, and i know other cars have to work harder.

It's a shame the diesal was discontinued, as I am sure that has plenty of power, and diesels are easier to modify to get even more power, at least in the truck market with devices like the BullyDog.

Don't get me wrong, I do love my Liberty and don't plan on trading it (and I hate the new Liberties, in fact I dislike all the new Jeeps except the Wrangler). But Chrysler didn't take the time to build a good motor/tranny/gearing combo.

*now back to your regularly scheduled programming*

Well, the engine and tranny are great technically. The problem is that it's too small of an engine, especially if you're lifted. The bigger the engine, the less stress the engine is putting into to move the car, the better the gas mileage. I've seen people go from v6s to v8s and gain 7 mpg.

Sport · **Posted:** Tue Oct 16, 2007 1:44 pm

jeepgirl0385 wrote:

*Sorry to interrupt regularly scheduled programming*

KJ4ME wrote:

i like the 3.7. has good power, fairly quiet, above average gas mileage, i like it a bunch. a v8 seems like it would be even more fun!

I'm not trying to be rude, but have you driven the 3.7? It has no power, and absolutely abismal gas mileage. It is quiet though, which is nice.

The Liberty is a relatively small SUV, it is similar to a Rav 4, or a CR-V (well size wise, not capability wise). If you look at fueleconomy.gov and look at the ratings on these similarly sized SUVs, you will see that the Liberty is one of the worst.

However, I do love my Liberty. I did buy it to commute, but I wanted to get there in all weathers, and I know my Jeep will, unlike the other "SUVs" that are more crossover than anything. I also like to know if I need to, I can tow 5000lbs.

Maybe it is the gearing that makes it feel so slow, but I got my butt whipped by my bf in a Geo Metro ("drag racing" to 50mph(speed limit) from a stoplight). The only reason I won was because the tranny in the Metro is bad so he missed 2nd, but he was still right there.

It really sucks how a 300hp high performance Camaro SS can get 28mpg highway, but yet a little 210hp Jeep can't even pull 20mpg unless it is all highway and you baby it. It's not like the Jeep drives around at high RPMs, it cruises on the highway around 2000rpms or so, and i know other cars have to work harder.

It's a shame the diesal was discontinued, as I am sure that has plenty of power, and diesels are easier to modify to get even more power, at least in the truck market with devices like the BullyDog.

Don't get me wrong, I do love my Liberty and don't plan on trading it (and I hate the new Liberties, in fact I dislike all the new Jeeps except the Wrangler). But Chrysler didn't take the time to build a good motor/tranny/gearing combo.

*now back to your regularly scheduled programming*

yeah and the KJ probably has 1500pds over the rav4 and CRV, I am sure that doesn't help. I tell you what, I feel much safer in the kj then I would in a rav4 or a crv. It is built like a tanks and drives like one too but it is solid and safe.

tjkj2002 · **Posted:** Tue Oct 16, 2007 1:52 pm

The KJ would be better on gas if we had more gear selections for the D30A diff,4.10's just doesn't cut it if running 31" tires and armor,now 31" tires and nothing else it would be back to stock form.4.56 gears would be a mpg gainer for those of us running 31"-32" tires and full armor(guzzles alot to start moving a tank).That is one reason for me doing a SFA swap(better gear choices)and then doing a 4.7 V-8 swap,more low end torque to get my heavy junk off the line.

Liberty V8

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