Big Bore Jeep Liberty

ManicMechanicJoe · **Posted:** Mon Dec 19, 2005 12:15 am

Does anybody know if a stroker or big bore kit is available for a 3.7? I REALLY want more displacement for torque.

ItalianBarista · **Posted:** Mon Dec 19, 2005 5:22 am

I don't think anyone has made one yet... However, the new Dodge Dakota and a few more vehicles from DC are going to have the 3.7 in them, so look in the near future for more accessories for the 3.7L engine! YAY!

CarNutCertifies · **Posted:** Fri Dec 23, 2005 12:24 pm

Have you thought about changing pistons in your current and putting a super charger on it...I read somewhere on a post that is why noone has a supercharger on theirs is because the pistons wont handle it.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

You can have custom forged pistons made since the 3.7 is basically a stroked 4.7 minus 2 cylinders. So yes, it can be bored and stroked. I would get Dan to make a set of 200 or 206 cams first though for a much better improvement for the money. As for the supercharger, I'm still trying to figure out KB's numbers from the one they built for shows.

It really should be a lot faster. Mine runs 0-60 in under 7 seconds, and the quarter mile in the high 15's without launching and without N2O. Also, the automatic 3.7 Liberty only puts around 155 hp to the ground on a Dynojet dyno. It looks like the numbers are adjusted to put about 20% of 210 hp to the ground on the stock run, but it's till 1.5 seconds slow in the quarter for stock. Maybe that was with MTRs and a lift.

performancechef · **Posted:** Thu Jan 18, 2007 9:37 pm

want torque? go with the M-benz turbo diesel 3.2 thats in all the jeeps in europe. i think its somthing like 380lb ft, it coming state-side in the grand cherokee 2007

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Or something like mine while it's on the bottle. 335 hp and 400 lb ft of torque is a wild ride in a Libby.

SS-Virus · **Posted:** Tue Jan 30, 2007 5:00 am

KY Liberty:
I'm going for some modifications. (As you can see in my signature) but I got some questions for you, because you have done some of them,
I contacted Dan, and he said he can offer me the TB, Cams, TC, and PCM program, but I don't know how I should know all of this, because the parts are not same in overseas vehicles, I already know that the TB is 02' style as Dan says after I show him some pictures,
Now I want to know about the transmission, for the TC. How can I know what type installed in mine.
What about the cams, are they same style in all 3.7L engines? How I can know what type to order?
Please I need full answers, if possible with pictures that will be great.
Appreciate you help.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

The 45rfe transmission uses 15 bolts for the pan, the 42rle uses 13. The cross member is also angled back for the 45rfe instead of being straight for the 42rle. The 45rfe has a seperate computer on the passenger side, and the ecu on the driver's side has 3 wiring harnesses instead of 4. If you have the 45rfe, you can get an upgraded torque converter and a shift kit. If you have the 42rle, you're out of luck. I would think that the cams would be the same in all the 3.7s, so what cams to go with depends on what rpm range you're looking to make the most power in. Some of this could be a little different on yours though. I know that the exhaust is different since those JBA headers fit yours. They only fit the 2005-2006 KJ's here in the US. They're still working on redesigning the ends to connect to the collectors to fit the 2001-2004's.

unixxx · **Posted:** Tue Jan 30, 2007 11:22 am

Quote:

You can have custom forged pistons made since the 3.7 is basically a stroked 4.7 minus 2 cylinders.

Are the 4.7L pistons a direct swap into the 3.7L?

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

unixxx wrote:

Quote:

You can have custom forged pistons made since the 3.7 is basically a stroked 4.7 minus 2 cylinders.

Are 4.7L pistons a direct swap into the 3.7L then?

Not really. The 3.7 pistons are 3.66 x 3.57 while the 4.7 pistons are 3.66 x 3.41. Anyone that makes custom forged pistons for the 4.7 would be able to make them for the 3.7. Also, the stock 4.7 pistons have the same problem with the rings being too high on the pistons and the ring land chunking off. Just not as bad of a problem because of the shorter stroke.

SS-Virus · **Posted:** Wed Jan 31, 2007 2:33 am

KY Liberty: Thanks for the help, I'll check them today and see what kind of trans. in my vehicle. and if no luck I am going to sale the Lippy and get a Grand :evil:

Quote:

I know that the exhaust is different since those JBA headers fit yours. They only fit the 2005-2006 KJ's here in the US. They're still working on redesigning the ends to connect to the collectors to fit the 2001-2004's.

Ithink no, they are the same, as the man who installed the headers for me, he also redesign the collectors, and put 2.5'' pipes. ( I'll get you some pictures & some sound clips)

Thanks again,

djformi · **Posted:** Wed Jan 31, 2007 4:29 pm

So with changing the pistons would you have to get new rods as well?

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Depends on how crazy you're getting. If you're replacing your pistons, you might as well upgrade the rods while you're in there. If you're adding boost, yes upgrade everything or you will blow it. Maybe after a year, maybe the first run. I'm not going to go that far with this motor. I'm pretty sure I'm just going to go with a set of 206 cams in it once JBA finishes my headers. The bottle is sitting in my garage right now and I think it will stay there for a while. It really will get up and move the way it's setup now. With the cams and headers it should be as powerful as I would would want it to be with the current suspension, tires, and rims. It seems like a Jeep Liberty RT, which is what I really wanted when I bought it. Just didn't exist. Making it like an SRT only came out of no upgrades being available for it at all. I can go overboard to make a point sometimes. I'm not racing right now though. A single run at the track can easily top $5000 in damage on a bad day. Plus I still have to do the interior. I have amps, speakers, an in-dash motorized vga touchscreen, a carputer, gps, sub, satellite radio, soundproofing, an carpet sitting in their boxes that I haven't had time to install. Still need to get the bodywork finished and the new paint too. This project has been on hold for 2 years. I think I need to finish this project, and then I'll decide if I should rebuild the race motor or buy a race car. That'll give you guys a little time to catch up...Just kidding. :lol:

unixxx · **Posted:** Wed Jan 31, 2007 10:39 pm

Put a 4.7 in it KY Liberty :twisted:

Some one needs to be the guinea pig :lol:

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

We very seriously considered building a 4.7 HO and squeezing it in the week it went out of warranty back in July '04. However, that was incompatible with my simple goal of being able to upgrade the 3.7's performance. It didn't look as though it would be safe it a front end collision either. Plus it was going to be difficult, and expensive even with a very good deal on the motor. If the motor gets swapped again, it will be to put the old block back in after it's been completely built.

Calvin56 · **Joined:** Fri Jul 08, 2005 1:59 am **Posts:** 345

performancechef wrote:

want torque? go with the M-benz turbo diesel 3.2 thats in all the jeeps in europe. i think its somthing like 380lb ft, it coming state-side in the grand cherokee 2007

Anyone want to fund a 3.2 transfer? :-p
http://cgi.ebay.com/ebaymotors/1998-mer ... dZViewItem

Found that on ebay- I'm dreaming of an engine transplant someday; I'd love to toss a diesel engine in there.

BTW do you know what tranny they run behind the Euro Jeeps' 3.2?

Big Bore Jeep Liberty

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