Magnum VS Hemi

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magnummopar

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This article is from magnum-swap dot com, i find myself explaining this topic a lot to potential customers. So i thought maybe whomever is considering an engine swap can have a short read.

I am in no way affiliated with their website, just looking to sway the world into the Magnum lifestyle.

"Magnum vs. Hemi
I’m sure the question has crossed your mind: Why not a 3rd Gen 5.7, 6.1, or 6.4 Hemi instead of the Magnum engine? The Hemi is newer, uses an aluminum block and heads where the Magnum uses iron, and the Hemis have a higher power rating than the 5.9 Magnum ever had. Besides, if you use a Hemi, you get to slap one of those cool “Yeah, it’s got a Hemi” bumper stickers on your car.

While there are definite advantages to using a new Hemi over a Magnum, the advantages for the Magnum are pretty significant.

Cost
The expense of the new Hemi swap is daunting indeed. First off, the crate and junkyard Hemis cost substantially more than the sub $1,000 junkyard Magnum engine, putting you significantly behind, expense-wise, from the beginning. Unless you get a free/very cheap Hemi, your total cost for a fire-breathing junkyard Magnum will probably be less than the cost of the Hemi engine alone.

Then there’s the expense of the swap itself. To install a new Hemi into a classic Mopar, a Hemi requires a different radiator, expensive custom headers and mounts, an aftermarket brain box to fire the coil packs and run the drive by wire throttle assemble, an expensive fuel injection system, or an equally expensive manifold and distributor for carbureted use. The Magnum uses common LA exhaust parts, engine mounts, and radiator. There are other requirements for Hemi swaps, but you get the idea.

If the additional cost of swap parts and the engine itself doesn’t dissuade you, there’s also the cost of performance upgrades. If you’re unhappy with the power your Hemi makes as-is, it’s going to cost a significant amount of money to upgrade it. One well-known Hemi vendor sells camshafts for the new Hemis for $800, and a carbureted intake manifold for $800.

I’m certain that as this is being written, the cost of this swap is coming down. Given time, there will be even more Hemi engines available, and the cost of the swaps will further decrease.

However, the last sticking point is still pretty hard to overcome, and that’s something that every Mopar guy can understand. Power! The fact is, Hemi engines just aren’t making more horsepower than the hot-rod Magnum engines. Sure, you throw stock Magnum up against a stock 6.1 Hemi, and the Magnum will come out on the losing side every time. But leaving things stock isn’t part of the typical engine swap plan…

In short, the Hemi will cost substantially more, require considerably more work and re-engineering of your car, and deliver roughly the same (or worse) performance as a Magnum engine."

- Magnum Swap . com
 
Well the problem might be "self solving" to some degree

LA / mag engines are no longer made, and the mag heads don't have "that" good a track record for cracking. As long as the aftermarket supports them, "fine." But we all know a bit about aftermarket quality, good and bad.

And this country used up a LOT of potential cores with the "cash for clunkers" program. Would be interesting to know just how many magnums got junked?

So as the LA / mag platform gets older, and less supported in parts, it too will become more expensive for parts, and less available on the used market. Around here, low miles mag engines are rare, and a 5.9 is a LOT more rare than a 5.2

Transmissions are their own problem, as A518s won't fit without tunnel work, and seems like most the pickups were 4x4. 2wd or vans are few between, as are A500's

Transmissions alone have sunk a deal or two for me on an engine, as you sometimes get a seller who wants to sell the whole vehicle, or won't split a (4x4) gearbox from a potential engine.

I recently spoke with a local yard in Spokane about magnums and price. They didn't have much of anything in magnums, but "would be glad" to fix me up with a hemi.......for a preposterous price. He indicated they had hemis "all over the place" meaning lots OF them, but he didn't seem to be willing to adjust the price!!!!
 
I might add that if you want EFI, it becomes a bit less clear.

An EFI Magnum requires the same expensive fuel system as the Hemi, so that is a wash, but if you want Hemi power from your SMPI 5.9 it get's harder to do. Pretty sure it is cheaper to have the security removed from a 6.1 ECU than get a 5.9 ECU tuned for 400 hp. Not that I have checked, just a guess.

And you can use Jeep manifolds and skip the expensive headers, too.

Not trying to sway anyone, just saying.

I will probably keep my LA, but more because it is the # matching block and I don't want to store it, and because it is getting close to becoming the uncommon swap these days. ;-)
 
"The Hemi is newer, uses an aluminum block and heads where the Magnum uses iron, "

Someone didn't get all the memo's.
If all Hemi blocks were aluminium those kinda swaps would be even more common.

But I do agree 'going Hemi' adds a lot of expense and complexity, especially in an A-body.


I put my own Hemi-swap for my daily Dart on the backburner in favor of a 360 motor, just for ease of simplicity.
I can't really afford (well, I just don't want) my daily to sit in the garage for a number of months while having to modify just about everything in the engine bay and routing a crapload of wiring to control the engine.
When the 360 is built it will take 1 good day in the garage for the swap to complete.
 
Actually the stock 95 and older computer and harness are easy to short cut wire to retro fit the magnums and mp pcm's are still available and will run a way more radical cam then the rt cam is. I was running a mp cam between the 300hp and 380hp cam. With no problems on a mp pcm in a 95 dak
 
Magnums are the best bang for the buck it's hard to come up with reasons to go any other way when it comes to dollar bills. The stock short block off tons of power potential.
 
Well the problem might be "self solving" to some degree

LA / mag engines are no longer made, and the mag heads don't have "that" good a track record for cracking. As long as the aftermarket supports them, "fine." But we all know a bit about aftermarket quality, good and bad.

And this country used up a LOT of potential cores with the "cash for clunkers" program. Would be interesting to know just how many magnums got junked?

So as the LA / mag platform gets older, and less supported in parts, it too will become more expensive for parts, and less available on the used market. Around here, low miles mag engines are rare, and a 5.9 is a LOT more rare than a 5.2

Transmissions are their own problem, as A518s won't fit without tunnel work, and seems like most the pickups were 4x4. 2wd or vans are few between, as are A500's

Transmissions alone have sunk a deal or two for me on an engine, as you sometimes get a seller who wants to sell the whole vehicle, or won't split a (4x4) gearbox from a potential engine.

I recently spoke with a local yard in Spokane about magnums and price. They didn't have much of anything in magnums, but "would be glad" to fix me up with a hemi.......for a preposterous price. He indicated they had hemis "all over the place" meaning lots OF them, but he didn't seem to be willing to adjust the price!!!!

I am sure tons and tons were scrapped for cash but luckily Dodge produced crazy amounts of these engines.

The transmission issue we will save for another time because it can become a nightmare quickly.

Availability wise, I spend some time every week calling for Engines, i just has three 5.2l engine delivered from Portland, Or. to the shop in Grants Pass, about 4 hours in a truck, for $1500. supposedly under 100k but we all know how junkyards are.

What was the cost of the Hemi up there?
 
Around here it's not too hard to find magnums for a decent price. I picked up a set of mag heads for 8 bucks a few months ago :) If someone can come up with a cheap alternative for A-body new hemi swap headers, I'd see it as a more viable swap option.

Although I believe I heard somewhere that you can use a certain dodge stock exhaust manifolds? But as hemi equipped trucks get older and older, the price is just going to go down boys! With hemis becoming more common place, speed parts will inherently go down in price as well.
 
If someone can come up with a cheap alternative for A-body new hemi swap headers, I'd see it as a more viable swap option. Although I believe I heard somewhere that you can use a certain dodge stock exhaust manifolds?

05 Jeep Grand Cheerokee manifolds are what I have in my notes.

FWIW, if you are interested in decent headers without too much of a ground clearance issue, you are looking at spending as much for headers as the Hemi swap ones would cost.
 
I can't answer for Del, but looking on Car-Part.com just now it looks like an '06 truck Hemi would be around $2250 or so, before shipping and a Charger 5.7 would be more like $3000. Might be cheaper cores, but I didn't look. A 5.7 '09 out of a Charger at the local dismantler is going for $4500.

In regards to a 5.9, there are 2 at Bill's for $350 each, but one has a pretty wide spread in compression and the other smokes (might be the intake, though). For a lower mileage one, looks like I would have to outside the area and might be able to get one for $700 before shipping.

I've already got a Magnum hybrid ('74 block, R/T heads, 5.9 roller cam) in my Duster, though.
 
The new gen 3 hemi blocks are iron.
Not say they all are but 95 percent are.
 
how about mileage? If its a factor, you just cant beat the 9mpg the Magnum offers around town......
 
how about mileage? If its a factor, you just cant beat the 9mpg the Magnum offers around town......

My 1965 Dart GT averages 13 in town, 9 when im playing, 17-18 on Highway at 70.

Stock 5.9L Magnum Lower End
Stock 5.2L Magnum Heads and Cam
Stock 5.2L Magnum PCM
 
Pretty sure there are a couple of individuals that have reported 25 mpg on the highway, with stock, basic 5.9's. It is the internet, though, so....
 
If and when I ever go away from LAs it'll be a gen III Hemi, the power potential is almost stupid compared to anything else. They are way more efficient than a LA or Magnum.
 
If and when I ever go away from LAs it'll be a gen III Hemi, the power potential is almost stupid compared to anything else. They are way more efficient than a LA or Magnum.

It's not just about power. Cost is always a huge issue for people, I also like the idea of a 318 or 360 staying with the same displacement and updated.

You can buy a Magnum and get 400 streetable hp out of a 5.9L for less than you can buy a used Hemi for.

The Hemi doesn't fit as well and how many Hemi's with rod knocks and flat lobes.

I AM NOT saying that the Hemi is a bad engine. Its awesome and can kick a** IF your budget allows.
 
Hey guys I really appreciate this thread it's good to hear the real world experiences. I'm paying attention.
 
A 360 Mag in an A Body sucking fuel is not the motors fault. Fault the driver with the heavy foot. The only time I drive mine easy is when I get caught in the rain.
 
In the '02 Rams, the 5.7 with the 545RFE was rated for an mpg over the 360 with the 46RE. There's a whole lot more factors to fuel economy than simply the engine.

An EFI Magnum in no way requires an expensive fuel system. In fact, it's cheaper to swap to a Magnum retaining fuel injection- at least here. Here cheap donors are 4x4.

Last I saw most JYs around were selling Hemis for $1800/motor. I dunno how bad/good the $1500 rebuilds are, had to wonder. The huge majority of the cheaper 5.7s (800-) had valvetrain issues or windowed blocks. Compare that to $500 as a pretty top warrantied 5.2 or $800 for 5.9s. Bonus is the 5.2s are all over the pick yards, and all in donors with everything for less than the high-rate JY cherrypicks.

As for Hemi power from Magnums, no-that's not a huge unknown. Sure, if you're going to compare a turbo Hemi to an N/A Magnum then there's a gap but apples to apples the Magnum is cheaper for power even though it starts lower. (the Magnums' HP peak is over 1000 RPMs lower than the Hemis- that's important to consider when noticing power differences) Hemi vs 360 isn't like 360 vs 318 or V10 vs 360- there isn't more power all over the power range everywhere.
 
An EFI Magnum in no way requires an expensive fuel system.

An EFI system requires a specific fuel system regardless of what is at the end of the fuel line, so I don't see how, in regards to the fuel supply system, a Magnum swap is any cheaper than a Hemi swap if you want to keep the EFI.
 
why would the transmission on a magnum motor be an issue. You could just run a 904 or a 727 behind them with either a properly balanced flex plate or a torque converter weighted for the magnum engine. A few of the RT truck guys are changing over to them because of the better performance capabilities at the track.
 
An EFI system requires a specific fuel system regardless of what is at the end of the fuel line, so I don't see how, in regards to the fuel supply system, a Magnum swap is any cheaper than a Hemi swap if you want to keep the EFI.
True. I have a whopping $600 in my entire EFI setup, since the motor came with a 2bbl.

The reason Magnum MPI is cheaper than that for a Hemi is while it's true in both cases that it's cheaper to keep the MPI, the Magnum is even cheaper to keep the MPI since the injected motors cost less but the OBD-II doesn't hardly seem like a horrid performance EFI system.
 
why would the transmission on a magnum motor be an issue. You could just run a 904 or a 727 behind them with either a properly balanced flex plate or a torque converter weighted for the magnum engine. A few of the RT truck guys are changing over to them because of the better performance capabilities at the track.

I was speaking in regards to keeping a trans from a vehicle that came with a Magnum Engine.
 
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