Just bought a 5.7 for my Duster

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7

7DUSTER3

1973 Plymouth Duster 360
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So i just picked up a 5.7 for my 73 duster and am super excited to drop it in my car. My father and i have been doing a bunch of research and have a semi clear idea of what we are getting into. I have been reading a lot but would like to see if someone might point me into the right direction for adding power to this motor. I have a built 450 hp 360 on an engine stand and would like to build a monster with the hemi to smoke my current engine.

I would like to keep the EFI, and would like to get as much power out of the motor doing everything shy of a supercharger or turbo.

What do i need to look for? I would love if someone could point me in the right direction to a complete build. What kind of cams are out there, head work? tuner? I need the works please!!!

Thanks
 
I might look into Stu at Inertia Motorsports. I got some stock parts from him, but they have some pretty impressive engines on their website. I think their performance heads and cam combo can get 450-500 hp or something if I'm reading their site right.
 
Does anyone know where i might be able to find out where my engine came out of? If i looked correctly there's no vin on the block. I just want to find out how old it is and what im working with. When it got to me it had already been pulled out and the truck was long gone. I called my local dodge dealer and they told me i was SOL.
 
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Looks like you have a 5.7 Hemi out of a Truck or Durango from 2003 to 2005 since you have the plug wires that fire across the motor. Basically the coils fired in a wasted spark setup firing both a plug on the compression stroke and the opposite piston on the exhaust stroke.

In 2006 they did away with the extra wires and used a single coil to fire both plugs in the head at the same time.

The intake is clearly the one used on the Truck and Dugango motors. The Jeep Cherokee uses the car style intake.

Hope this helps,

Regards,

Joe Dokes
 
There was a thread on here a while back that detailed the info that's listed on that sticker on the valve cover. Don't remember the name of the topic exactly and what information was actually given on the sticker, but you might look for that and see if it clears anything up.
 
I appreciate all of the help gentlemen. I know for sure it came off of a truck but just didnt know what year. I can now start to slowly piece it all back together. I'm going to find that thread as well. Thanks!
 
I want to believe that this is an 03 hemi, and from what i've read its not the most desirable hemi to work with, Is this correct? Plans for this thing include

Replacing the missing throttle body (aftermarket i hear is useless) but i need one anyways
Going through the internals and replacing what is needed
Keeping the EFI and have it be more streetable (dont know anything about the wire harness mess or where to get it to keep the fuel injection) RECOMMENDATIONS ANYONE???
Swapping The cam and changing corresponding parts. I want something beefy RECOMMENDATIONS ANYONE???
Fix the broken fuel rail with aftermarket ones. (are these worth while to swap?)
Get TTI headers
Replace the serpentine belt system with something a little fancier
New plugs and wires (worth it???)
Either new Heads or Work done to mine RECOMMENDATIONS???

What else besides a supercharger/turbo/stroker can i do to it to gain HP??
 
I would opt for a carbed application. If your not familar with EFI tuning, I'd stay away from it especially when you'll need a good set of heads, valve springs and cam package to get to your hp goals. With the truck intake you have, hp flattens out at 5600 rpm. I like the looks of the Edlebrock dual plane, but have never had the chance to dyno'd one yet. Your stock rods are good to about 7000 rpm. Above that I've seen the big ends go out of round.
 
hemidup said:
I would opt for a carbed application. If your not familar with EFI tuning, I'd stay away from it especially when you'll need a good set of heads, valve springs and cam package to get to your hp goals. With the truck intake you have, hp flattens out at 5600 rpm. I like the looks of the Edlebrock dual plane, but have never had the chance to dyno'd one yet. Your stock rods are good to about 7000 rpm. Above that I've seen the big ends go out of round.
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Im kinda tossed between the idea, I would much rather spend the cash on my la 360 if i wanted to stay carb'd. I think the fuel injection is where we are headed with it. The engine is going to need to be rebuilt as is so id rather pay for brand new upgrades. Is it worth it to put the time and money in the 03 engine?
 
I don't know if the 2003 5.7 Hemi is anymore desirable to work with than other years. I would consider all 2003-2008 to be nearly the same in overall terms of durability and hot-rod ability.

The 2003 Hemi's had two computers one for the engine and one for the transmission, all Hemi's use a drive by wire setup, though the 03 had a standard pedal that actuated a cable that pulled on a box under the hood that sent an electrical signal to the computer, which then sent a signal to the throttle body either opening or closing it.

Some later year hemis are a bit more difficult to hot-rod because they had cylinder deactivation, this began in 05 for the cars and 06 for the truck engines. 2009 and later saw the introduction of revised cylinder heads and cam phasers that allowed the computer to adjust the cam timing to improve mid range torque and horsepower. The later 09 Heads are superior to the 08 and earlier heads flowing about 20 CFM more on the intake side. Stock 09 heads flow about 295 CFM on the intake side vs 275 for the 08 and earlier heads. 2008 and earlier heads can be ported to over 300 CFM with stock valves and into the 320 range with larger valves.

I don't have a particular recommendation for cylinder head but Stan Weiss has created a database of cylinder head flow number on both the 5.7 and 6.1 hemi heads. You can read it here:

http://users.erols.com/srweiss/tablehdc.htm

The stock throttle body is 80mm if you are going use the drive by wire and the factory computer, you have three basic choices. Stock, 85mm and 90mm aftermarket, though Kennebell makes a giant drive by wire throttle body for their blowers.

Here are a couple of links to throttle bodies:

http://www.shophemi.com/c-488-hemi-throttle-bodys.aspx

http://www.kennebell.net/KBWebsite/Accessories_pg/Mammoth Dual 1880/layouts/mam1880.htm

Camshafts, I am probably going to run one from hughes engines, they offer re-ground cams at really good prices, which is an important consideration for me. The limits for a stock hemi lower end is about .550 lift anymore and you are likely going to run into piston to valve clearance issues. Here's there camshaft page:

http://www.hughesengines.com/Index/...3LzYuMSBNb2Rlcm4gSGVtaQ==&level1=Q2Ftc2hhZnRz


My preference is to retain the efi, yes the learning curve is a bit steeper, but why degrade a motor? I think once you learn EFI you'll wonder why anyone would ever build a carbureted engine.

Regards,

Joe Dokes
 
hemidup said:
I would opt for a carbed application. If your not familar with EFI tuning, I'd stay away from it especially when you'll need a good set of heads, valve springs and cam package to get to your hp goals. With the truck intake you have, hp flattens out at 5600 rpm. I like the looks of the Edlebrock dual plane, but have never had the chance to dyno'd one yet. Your stock rods are good to about 7000 rpm. Above that I've seen the big ends go out of round.
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I'll bet you watch black & white movies on your HD Tv too! LOL
 
I am surprised no one has mentioned the 03 valve springs. They are weak. And are a common faiure. The 03 is no different form the other motors (oter than the valve springs and not having EGR) what makes a 03 undesiarabile is the lack of tuning on the 03 pcm. But if you don't have one, then you should look at finding an 04 or 05 pcm and harness. And if you go with the drive by wire the throttle body will need to match the 03 and 04 had a different plug from the 05.

a set of big valve heads and a properly sized cam will do wonders for that motor. You could chat with stu at inertia about your plans. He is a site sponsor and knows his motors.

I would stay away from a stock reground cam you will probably not see the power numbers your after. As you cannot make them large enough.

when it comes to efi, get the motor built and buy a diablo. Find a tuner and getting it up and running will be fairly easy for an experienced hemi tuner. (the best one I know of is in sacremento)
 
So ,if i am reading this right,since we dont have a computer and throttle body yet, we could get one from a say 05 and some of our tuning probs would be solved. Correct me if im wrong


bob
 
you are correct. But you will need the correct throttle body, and you will need to add in egr as the 03 did not have it and you willl end up with a code for it. Now if your not worried about emissions then this is not really an issue, if the egr does not function it's just a light
 
03ramit1 said:
you are correct. But you will need the correct throttle body, and you will need to add in egr as the 03 did not have it and you willl end up with a code for it. Now if your not worried about emissions then this is not really an issue, if the egr does not function it's just a light
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If you get the ECM flashed, I'm pretty sure they can program out the EGR.
 
tin you are correct they can, but bolting an egr vavle on is really a simple task. It has just about 0 effect on power and emissions are not always a bad thing.
 
My 05 engine from a 2500 4x4 truck does not have EGR.

I rewired the factory harness and will be using a stock PCM. I'll likely eventually use a predator to tune and maybe add a cam, but my power desires are pretty conservative.

One other option no one has mentioned is the programmable EMS. It's pretty pricey though. The mopar part number is: P5153528 computer and P5155529 harness for EFI applications.
 
you are correct the 2500's don't have egr. Forgot about that. I mainly deal with 1500's so a 2500 pcm would work for him too.
 
Ok guys I gonna throw this out there at ya. the Duster was a /6 originally so we have a /6 k-member in it w/shumaker mounts to hold the now 360. Would this k-member hold the Hemi or should we swap it out with a v-8 k member or better yet a newer style front suspension ???
 
MR.7DUSTER3 said:
Ok guys I gonna throw this out there at ya. the Duster was a /6 originally so we have a /6 k-member in it w/shumaker mounts to hold the now 360. Would this k-member hold the Hemi or should we swap it out with a v-8 k member or better yet a newer style front suspension ???
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> A well designed coil-over suspension with better brakes, will take some weight off, ride,handle and stop better. Headers can dump better(no torsion bars), you should be able to better enjoy that bundle of, under the hood. Good Luck,ateam. :thumrigh:
 
The tti mounts were designed using the v8 k frame. I don't know if you would be able to use a slant k with them but my gut says no. Although a few bucks a RMS suspension will give you a lot more room for exhaust and allow you to keep power steering if you wold prefer. It installs easily.
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