Hemi swap resource thread

I built my engine to 2005 Ram 5.7 Hemi specifications. Front timing cover/intake/throttle body/alternator/AC/oil pan/etc are all Ram truck pieces…

Any ‘03-‘08 5.7 Hemi block and heads would have worked for a base starting point…

I switched my valve covers & ignition coils to the later 2007+ Hemi ignition setup though. That way there are no plug wires. It’s just a cleaner platform. My ignition coils are basically the same pieces used all the way through units installed on the Hellcats. You just need to let whom ever is building the engine harness know…

I went with a 2005 545RFE 5-speed transmission out of a Durango. Ram would have been the exact same…

Fuel tank and NVLD from any ‘05-‘06 TJ work. They plug in as stock to each other. The only thing I had to change was the fuel line connection. The new electrical plug-in for the fuel pump will already be installed in the new conversion harness…

I mounted the NVLD in the rear passenger side wheel well just like the newer TJs. It only took a bit of trimming and a couple holes drilled…

Any ‘01-‘06 gauge cluster will work. You just need to know what year it is from to get the correct wiring diagram so you can splice the 2 new gauge connectors into your current dash harness…

All you need to do is send your underhood PDC fuse box and it’s attached harness to Chris at HWA and he will work his magic…

Good info, but Just a couple of clarifications. The coil on plug setup did not start in ‘07. My ‘06 runs the coil on plug - but I’m not sure what year they started. It is a nicer setup - especially if you hate spark plug wires (and LS’s…🙂).

The ‘03 to ‘08 Gen III Hemi will work, but for the stock gauges in the ‘01 to ‘06 TJ to work you need to run an ‘05 (or prior) ECU. The ‘06 to ‘08 Hemi (at least in the Ram) used a CAN BUS setup, which is not compatible with the TJ cluster. For the ‘01 and prior TJ, you will need to source an ‘02 to ‘06 TJ gauge cluster, or go custom gauges. Further, if you use the wiring harness from an ‘06+ Hemi, the harness has to be modified to ‘05 specs (among the other necessary changes).

The fuel tank mod is required because the Hemi fuel injection requires 59 pounds of fuel pressure. The ‘04 and prior TJ pump does not make enough pressure. You can solve it by swapping in an ’05-‘06 tank (which makes the 59 psi), but you can also install and ‘05 pump into an ‘04 tank with just a minor modification. A little trimming of the top ring on the housing and it works. The required wiring change is the same.

By far the best resource I have found for info on a Hemi swap into a TJ is the conversion guide written by Jim Bebe at Red Rock Off Road. I believe you can still buy it on their sight.
 
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1) I have the Savvy 1.25” body lift so I went with the MORE 1” taller bracket. Just to keep the steering shaft in better alignment. You are correct that the four-cylinder bracket can be used though…

2) The 2005 Ram 5.7 Hemi Power steering pump works beautifully with the TJ steering gear. At least it does with the early box. I am not sure about the later Mercedes box…

3) A TJ 4.0 power steering pressure line works perfectly between the Ram pump and the earliy TJ steering gear. You only have to bend the one end a little to go in the Ram power steering pump…

The low pressure line needs to be fabricated though. You need to go from the 5/8” hose nipple on the Ram reservoir to the early TJ steering gear low pressure port. It can be done several ways…

4) I actually bought a hydraulic crimper and made all my own AC lines. An AC shop can easily do it though…

5) I do not have cruise control. I believe Hotwireauto has an aftermarket kit that will work…

I originally ran the stock Hemi PS pump, but I also run hydro-assist steering and hydro-boost brakes. The stock pump was not enough volume or pressure for that setup. For a stock setup, either Mercedes or saginaw, it is certainly fine. Good news is that PSC makes a performance pump which will bolt to the Hemi, and that did solve my issues.
 
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Good info, but Just a couple of clarifications. The coil on plug setup did not start in ‘07. My ‘06 runs the coil on plug - but I’m not sure what year they started. It is a nicer setup - especially if you hate spark plug wires (and LS’s…🙂).

The ‘03 to ‘08 Gen III Hemi will work, but for the stock gauges in the ‘01 to ‘06 TJ to work you need to run an ‘05 (or prior) ECU. The ‘06 to ‘08 Hemi (at least in the Ram) used a CAN BUS setup, which is not compatible with the TJ cluster. For the ‘01 and prior TJ, you will need to source an ‘02 to ‘06 TJ gauge cluster, or go custom gauges. Further, if you use the wiring harness from an ‘06+ Hemi, the harness has to be modified to ‘05 specs (among the other necessary changes).

You are correct. On the Ram engine the dual plug coil started in ‘06. Good catch…

The ‘05 Ram ECU seems to work well with the ‘01-‘06 TJ clusters. I run the ‘05 Ram ECU and an ‘01 TJ cluster in my Jeep. Works beautifully…
 
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You are correct. On the Ram engine the dual plug coil started in ‘06. Good catch…

The ‘05 Ram ECU seems to work well with the ‘01-‘06 TJ clusters. I run the ‘05 Ram ECU and an ‘01 TJ cluster in my Jeep. Works beautifully…

Interesting. As I understand it, the '97 - '01 TJ platform uses a CCD Bus system, which should not be able to communicate with the '05 Hemi ECU, which runs PCI. Hemi ECU's ran PCI from '03 - '05. The TJ platform ran the PCI bus from '02 - '06. I wonder if it was a mid-year '01 conversion?

But again, just my understanding - I could be off by a year.
 
Interesting. As I understand it, the '97 - '01 TJ platform uses a CCD Bus system, which should not be able to communicate with the '05 Hemi ECU, which runs PCI. Hemi ECU's ran PCI from '03 - '05. The TJ platform ran the PCI bus from '02 - '06. I wonder if it was a mid-year '01 conversion?

But again, just my understanding - I could be off by a year.

I’m not sure. Hotwireauto states on the website that ‘97-‘00 clusters would need to be replaced with a newer TJ gauge cluster. So that is what I went by…

4EED0779-8F49-417F-A154-42CE9FE894C7.jpeg
 
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And a little eye candy for the thread:

IMG_3582.JPG


And a little insight into my build. Prior to the Hemi I ran a supercharger on the 4.0. It made about 300 hp and 400 torque at the flywheel. The '03 - '08 Gen III Hemi made something like 345 hp and 375 torque. No way I was going through all that work for a little more hp and less torque. So I built the Hemi. Molnar forged crank, pistons and connecting rods, 10.5:1 compression, bored 20 over, a mild cam and some head work. I also had ATS do a stage 4 build on the 545FRE to take 700 hp. The math puts it at about 399 cubes, but I call it a 392 because, well, 392... :cool:

On the chassis dyno, with my crazy heavy drive train, it made about 390 at the wheels, and about the same torque. Although I've never had it on an engine dyno, it's likely north of 500 at the crank.

My biggest regret was not doing more with the heads - which is the big limiting factor on this version of the Hemi. The subsequent Eagle heads were a huge improvement - flowed significantly more, and therefore make a good bit more power. I've looked a few times at installing a set of ported Eagle heads, and I've come close to pulling the trigger a few times, but it would also require rebuilding the exhaust as it would need a new set of headers to handle the different exhaust port configuration. Building the exhaust was the most challenging part of my build - don't really want to do that again...

Finally, the exhaust was another mistake I made. I run 2.5 pipes through 2 2.5" cats, and then into a custom Y-Pipe - into a 2.5" muffler and tail pipe. This would have been fine for a stock '06 Hemi. What I should have done is go dual all the way out the back, or at least merge into a 3" pipe, muffler and tail pipe. Flyin' Ryan told me I'm likely giving up a good chunk of HP because of that. But, it runs and sounds good. I guess that's another reason to do the Eagle heads...:rolleyes:
 
1) I have the Savvy 1.25” body lift so I went with the MORE 1” taller bracket. Just to keep the steering shaft in better alignment. You are correct that the four-cylinder bracket can be used though…

2) The 2005 Ram 5.7 Hemi Power steering pump works beautifully with the TJ steering gear. At least it does with the early box. I am not sure about the later Mercedes box…

3) A TJ 4.0 power steering pressure line works perfectly between the Ram pump and the earliy TJ steering gear. You only have to bend the one end a little to go in the Ram power steering pump…

The low pressure line needs to be fabricated though. You need to go from the 5/8” hose nipple on the Ram reservoir to the early TJ steering gear low pressure port. It can be done several ways…

4) I actually bought a hydraulic crimper and made all my own AC lines. An AC shop can easily do it though…

5) I do not have cruise control. I believe Hotwireauto has an aftermarket kit that will work…

Thanks!
 
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Another option that I went with was replacing the cross wire plug wire system with the shorty plug wires that do the same thing as the later model black plastic valve covers with the dual plug coils. I wanted to keep the aluminum valve covers and paint them HEMI orange just mostly because I'm old school and like the retro look. Off the top of my head I don't remember who I got the shorty plug wires from because it was over 2 years ago when I bought most of the things for my swap before putting on hold starting with the pandemic..
They may not be quite as clean as the bigger coils, but again "old school" and I like the looks of the wires. Eye of the beholder.

They do come in a few different colors, I liked the red...

IMG_20221128_193217414~2.jpg
 
Another option that I went with was replacing the cross wire plug wire system with the shorty plug wires that do the same thing as the later model black plastic valve covers with the dual plug coils. I wanted to keep the aluminum valve covers and paint them HEMI orange just mostly because I'm old school and like the retro look. Off the top of my head I don't remember who I got the shorty plug wires from because it was over 2 years ago when I bought most of the things for my swap before putting on hold starting with the pandemic..
They may not be quite as clean as the bigger coils, but again "old school" and I like the looks of the wires. Eye of the beholder.

They do come in a few different colors, I liked the red...

View attachment 390636

I gotsta admit, the main reason I went with these Accel buggers was that they matched the rig…

7CEFA528-0342-496E-A377-4B1C32D9E336.jpeg