Hi, I have a WK2 5.7L, and I was thinking of doing a possible engine swap if able. Has anyone ever done or heard of a working 6.4L swap? If so, is it straight drop and bolt, does the connectors fit the between both? I tried to search, but couldn't find much info on it.
Engine swap
1 - 17 of 17 Posts
Joined
·
1,978 Posts
Unless you're getting the 6.4 from a junkyard and it comes with the computer, I imagine a new computer to run the 6.4 would be kind of pricey.
Exactly ..I looked into swapping a 6.4l into my jeep and when you really look at all that's involved you either upgrade your existing motor or trade in the vehicle and buy an srt
All the ecu stuff is different ..I'm not sure the tranny is a direct bolt up either?
I,ve been told that swap from 5.7 to 6.4 is just bolt on. What you need then that is custom tune of your ECU or flash engine software from 6.4.
Do not touch TCM as the transmissions are different. I guess that Sean from hemifever could solve issue with tune.
But engine should be in full set with injectors, intake, etc. You also need to care about exhaust as 6.4 has different. You will definitely need srt headers and cats and might be cat back srt exhaust as its also based on larger tubes than 5.7.
But note that at the end you will never reach close to srt dynamics having 5.7 6RFE trans and 5.7 differentials ratios. If you already have MY14 hemi with 8HP transmission then engine swap or any modification like charger or stroker kit makes more sense.
I believe that for older wk2 5.7 with 6RFE trans there is no sense to touch engine at all.
Sent from my iPhone using JeepGarage
Do not touch TCM as the transmissions are different. I guess that Sean from hemifever could solve issue with tune.
But engine should be in full set with injectors, intake, etc. You also need to care about exhaust as 6.4 has different. You will definitely need srt headers and cats and might be cat back srt exhaust as its also based on larger tubes than 5.7.
But note that at the end you will never reach close to srt dynamics having 5.7 6RFE trans and 5.7 differentials ratios. If you already have MY14 hemi with 8HP transmission then engine swap or any modification like charger or stroker kit makes more sense.
I believe that for older wk2 5.7 with 6RFE trans there is no sense to touch engine at all.
Sent from my iPhone using JeepGarage
I'm thinking about getting a MY14 or MY15 and doing that engine swap. I just want to get as much info about the swap as possible before I proceed.
Joined
·
108 Posts
OK, I'll bite.
Let's ASSUME it's a bolt in deal. By the time you pay for the 6.4 engine, and factor in the depreciation you'll add to the new Franken-mobile... not to mention the labor pains of getting all the electronics worked out or labor costs if need, and certainly your time... you will have spent at minimum SAME money as if you'd just traded for a new SRT.
Why go through all of that... and have a half-assed, pseudo-SRT when you could have a real SRT for same/less money.
Personally, a 5.7 Hemi WK2 is a pretty damn good SUV. Operative word ESS - YU - VEE.
If you want a sports car take the $$ you have squirreled away for engine swap and find a nice used Honda S2000. Just as quick, and a helluva lot more fun on a track.
Let's ASSUME it's a bolt in deal. By the time you pay for the 6.4 engine, and factor in the depreciation you'll add to the new Franken-mobile... not to mention the labor pains of getting all the electronics worked out or labor costs if need, and certainly your time... you will have spent at minimum SAME money as if you'd just traded for a new SRT.
Why go through all of that... and have a half-assed, pseudo-SRT when you could have a real SRT for same/less money.
Personally, a 5.7 Hemi WK2 is a pretty damn good SUV. Operative word ESS - YU - VEE.
If you want a sports car take the $$ you have squirreled away for engine swap and find a nice used Honda S2000. Just as quick, and a helluva lot more fun on a track.
Joined
·
382 Posts
I've done it (not in a GC but twice in chevy trucks). What I will say is that it always costs way way more than you would think. It starts out as engine + a few extras, and the further you get into it the more you spend: if you got everything apart you might as well do a new water pump, ditto for ujoints, or my personal favorite - new engine (which on paper is fine with tranny) nukes tranny that is a little tired. There are a 100 little things that you don't think of up front that come up.
In this case I think you would end up being cheaper to just buy an SRT (not even counting in labor).
I recently spoke to someone from JeepAreUs, as they carry the 392 hemi engine for around $7.5k, and I was told that it was a direct drop, with a computer reflash. To make things easier, I priced out a MY16 5.7L loaded, and a MY16 SRT, and the difference was roughly $18k more for the SRT. Now if I was able to just switch out the engine, that would be a 10k difference to do other things with. I'm not worried about the labor to do the swap, I'm merely concerned with how possible it is and if someone had done it successfully.
Joined
·
382 Posts
It sounds like you are pretty committed, and it would be a fun swap to do. However, let me put one final caveat out there. If you do as you suggest above and buy a MY16 5.17 loaded (lets call it $47k-ish) and you put another 7.5k into a new motor, and some amount of incidentals (lets say 2.5k for a nice round number). You now have $60k into a jeep that may be very difficult to sell. If you plan on keeping it forever, no problem. But if you like to change every 2-4 years it could pose a problem.
For example, I have a buddy who bought a brand new dodge dakota in the early oughts (2wd, reg cab, short box). Drove it home, pulled the motor, and had a viper v10 professionally installed. It's a tiny truck with a gigantic motor and it is a ton of fun. However, at the time it was a $20k truck with $25k+ worth of motor in it. Today it is a $5k truck with $25k worth of motor in it. He has tried to sell it a few times, but it never seems to generate any interest.
Bottom line is most people shy away from heavily modified cars as they don't always trust the work was done right. So in considering such a significant swap, you should really evaluate how long you plan to keep the vehicle. If it is 5 years or less; something bolt on like a super-charger, or a used SRT might make more sense.
Joined
·
108 Posts
I think it's interesting to explore the possibility. I love to see the final outcome... I'm just not the guy to put my money there.
As I mentioned, and Crombenevolent points out... if you plan on keeping it and sort of a money-is-no-object point of view. It can be done. But the finished product will be worth way less than an unmolested version of the same vehicle. The $10K savings you think you might have on doing a swap yourself, evaporates to a negative number in a hurry when you factor in the vehicle's worth after said transplant. I don't see any ROI in this case, hence I don't see what your purpose for doing it would be.
As I mentioned, and Crombenevolent points out... if you plan on keeping it and sort of a money-is-no-object point of view. It can be done. But the finished product will be worth way less than an unmolested version of the same vehicle. The $10K savings you think you might have on doing a swap yourself, evaporates to a negative number in a hurry when you factor in the vehicle's worth after said transplant. I don't see any ROI in this case, hence I don't see what your purpose for doing it would be.
might be 5.7 headers could be fitted onto 6.4 engine but that is not the best idea. So have srt exhaust in the mind.
Sent from my iPhone using JeepGarage
Check my posts, I have just done it.
Joined
·
2 Posts
It is still going strong. Have ordered 3” cut outs, next project is to put on the 6.4 headers, (still using the 5.7 headers and exhaust) then a full new 3” exhaust system. And then a re-dyno tune.
1 - 17 of 17 Posts
Join the discussion
