Engine Swap Overview

Discussion in 'How To' started by TwoBobsKJ, Mar 9, 2013.

  1. TruckerKevin

    TruckerKevin Full Access Member

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    I have a question, if anyone is still monitoring this thread.

    I have a junk motor out of an 03 with a rod knock. I would like to rebuild it and put it in my 07 some day when my 07 wears completely out. Just for a hobby. So basically I am going backwards from this thread, and putting an older 3.7 liberty motor into a newer liberty.

    From what I gather from this thread, I need to replace reluctor ring, cam ring, and transfer the oil pan, intake manifold, motor mounts, and tap out the heads for the power steering pump. Does this sound correct?

    And if so, what about the EGR valve? Te 03 did not have an egr but my 07 does have one.

    Can what I want to do even be done? The blocks and heads are identical aren't they? (besides the ps pump holes on the head)
     
  2. renegade 04

    renegade 04 Full Access Member

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    I would not even bother putting the EGR back on with the new engine, and one thing you will notice is less power and less torque. The new 2007 engine has a better cam shaft profile and also higher compression then the 2002.
     
  3. TwoBobsKJ

    TwoBobsKJ Full Access Member

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    You are correct.

    When you rebuild the '03 are you having a shop do it or are you doing it yourself? If a shop does it request that that build it to '07 specs so you get the improved compression, oil flow and so they fix the valve seat issue (they had a tendency to drop in the '02 thru '04 engines.) And just block off the EGR with a plate.

    You can use the oil pan, manifolds, etc from your '07 - they will all work with the '03 engine. The only reason I mentioned that in the original post was because the '07 block I used came out of a Dodge Dakota so those parts wouldn't work in my Liberty.

    Let us know what you end up doing :waytogo:

    Bob
     
  4. TruckerKevin

    TruckerKevin Full Access Member

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    I was not sure if I blocked the EGR off if that would screw with the computer or not, I was thinking perhaps it was programmed to look for the EGR and if it didn't have one, cause me issues.

    I was going to do the short block myself,,,,,, well, measure the bearing clearance and have the machine shop bore and turn the crank and whatever else is needed.

    I considered just buying the heads. There is a builder out of Florida that seems to rebuild lots of these, they had a pair of heads for $650 and had the valve problems fixed. We have a good machine shop here that has been here for years and has a good reputation, but I am unsure if they know the 3.7 valve issues well enough. And those on eBay do not require a core.

    04-11 DODGE JEEP 3.7L CYL HEADS PAIR WITH OR WITHOUT EGR | eBay

    That is, of course, that they are still around when I am ready.

    I read your reply in my other thread about the torque converter, I appreciate your input. Ill revisit this thread when the time is near. Right now it is only 10 degrees out and I do not have a heated shop,,,, this is a for sure spring project!!
     
  5. Rchobbit

    Rchobbit New Member

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    Engine swaps

    I have an 03 liberty with a blown motor. I'm getting ready to by a complete 05 for the motor. What I'm trying to figure out is do I have to change the reluctor ring or can I change the ecu's and then will the 05 run?
     
  6. TwoBobsKJ

    TwoBobsKJ Full Access Member

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    Nope, you need to change the reluctor ring and cam sprocket. Everything about the computer is different so there's nothing to flash to make it compatible.

    Sorry :blah:


    Bob
     
  7. Robochop

    Robochop New Member

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    2002 3.7 into 2003 Liberty

    Hi everyone,
    I'm no stranger to rebuilding 3.7's, but I recently aquired a beautiful 03 liberty with 240k smoking miles on it. I had a good 02 block sitting in the garage and did a "frankenstein" and built around it, using the 03 parts. Had the heads redone at a local machine shop. new timing chains, water pump, oil pump, etc. I used the same cam sprocket & sensor, crank sensor and all other sensors from the 2003.
    I got it all back together and it won't start. It actually sounds like the timing is off. The machine shop told me the crank reluctor wheel was the same for the 02-03 3.7's. I have tried swapping crank and cam sensors to no avail.
    Any suggestions?
     
  8. JBDive

    JBDive Full Access Member

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    So I just had my 02 engine replaced with a rebuilt engine. The idle is a bit rough for what I think it should be. Is this a computer issue with an old 02 computer and possibly newer engine?