Getting Ready for the Magnum Swap. (help?)

-
replicaracer43 said:
And in your junkyard 5.7 comparison, you forget it requires about a $1000-$1500 wiring harness and computer to make it running, crazy expensive headers, aftermarket oil pan and mounts ect. Ect. and LOTS of those 5.7s have camshaft and lifter failure...a magnum 5.2 or 5.9 can be done in a weekend easily
Click to expand...


DAMN!!!! Done and Installed in a weekend????

OK Don't mean to steal the thread away but one final question and then back to the regularly programmed schedule (thread) wink

So with that said I have come across a 2000 5.9 with 173K mi - locally and guy wants $500 - thoughts?

I would still have to buy motor mounts because I have a Slant 6 in mine
 
Oh I see what happened. You erased the “QUOTE” tags.
prican_2000 said:
"Magnum Swap is the most cost effective swap to do" - Is it really?!?!?!?!!?
When taking into account that you will have to replace the heads, if you go with the Hughes heads they're $1200!!!!
Click to expand...
Negative!!!! You may very well NOT have to replace the heads to get the swap done and up and running.

Which brings me to a question - are "ALL" the 5.9 heads prone to the hereditary cracking? or is this specific to certain years Magnum motors or head manufacturing number???????
Click to expand...
I’m told they all crack. I’ve onky messed with a pair of Magnums and they ran fine. 1 5.9 has 380,000+ miles and ran like a freakin champ. Heads cracked? According to some they Guarantee it. But I never checked. It did not burn oil, it did not overheat, I got 19 miles to the gallon in the ‘99 Durango.

But back to the cost effective swap statement - if you buy a 5.9 for approx. $500 then add the $1200 for heads and whatever other expenses to rebuild, gaskets etc addressing any "possible" issues before stabbing the motor in - that puts you in the $2K territory which is New Gen Hemi pricing (used 5.7). Am I missing something here?m
Click to expand...
Answered above. However, if your going to put new heads on, why stop at stock? Put some well ported heads on top and cam it. Good to go with more power. Looking for big power? Add a MLS gasket that is slightly thicker than stock and then supercharge it. Combined with a cam and ported heads, upper 500’s is easy pickings.

^^^ That is mainly the reason why I have not bought anything yet or decided on which powerplant to go with. I am not looking for a Race Car - I mainly want a Cruiser with good street manners but still have a respectable HP. And I tell you what I have a 2006 300C that previously had a 5.7 with a mild Cam and that thing was AWESOME!!!! HP on demand (low 12s in the 1/4) and that was with a 4500lb Whale of a car - I cant imagine what that same power plant would do in a car that is almost half that weight. hmmmmmmmmmmmmm
Click to expand...
The problem with what you wrote here is that your comparing a modern Hemi engine with what is a better build from the factory with heads that are stock but yet flow more than ported Magnum heads as well as a aftermarket head or two and leaving the multiple speed transmission out of the math equation.

When you compare, look at all the workings of what makes it what it is. Then realize the extra work that is needed to be done on what it takes to get the Magnum at a similar/equal level.

Start cheap or spend a lot to equal the HEMI or spend a lot upfront and add little to achieve the goal. Welcome to the wonderful world of hot rodding with what is known as the great catch 22!

Another way to look at the problem is what you also mention, car weight. While the Hemi moves that 4500lbs. tub into the 12’s, it does so with that multiple speed transmission. You don’t need that but a good general plan to move your cars weight, not the 4500lbs. Look at your cars weight and then also decide if making it lighter is in the cards.

Lighter car equals less HP to run the same times.

What was the specs of the cam you used in the 5.7 HEMI?
 
Last edited:
prican_2000 said:
DAMN!!!! Done and Installed in a weekend????

OK Don't mean to steal the thread away but one final question and then back to the regularly programmed schedule (thread) wink

So with that said I have come across a 2000 5.9 with 173K mi - locally and guy wants $500 - thoughts?

I would still have to buy motor mounts because I have a Slant 6 in mine
Click to expand...
I myself self would go for it.
Sit down and do the math on the extra parts needed to run the low 12’s. I still don’t know the weight of your car but normally this is not a gas friendly endeavor. Weight dependent, is look at the sticky threads on running 12’s & 11’s.
A supercharged engine would seriously reduce the need for a big cam.

Add an overdrive trans for mileage. Aredul gear selection would help a lot. The overdrive ratio for the MP A-500 is (IIRC) .69.
.69 X’s the gear ratio equals the final drive ratio while in OD.

Here is an example;
4.30’s X .69 = 2.96 final drive gear ratio.
A 2.96 gear ratio with what size tire delivers what driving rpm at what speed? (That you drive in.)
Now select a cam that can cruise in that range and see if it fits the ET you seek.
 
Last edited:
The cracked head issue is so stupid. Yes, they will be cracked. They pretty much all are.

My grandpa bought a 1994 ram brand new and put ~350k miles on it. He bought a low mile 1996 ram around 2000. The 94 was eventually repainted, new seat, etc and given to me on my 16th birthday in 2007. Drove it for years before it got rear ended and totalled. He has retired and is still limping around in the beat up and UGLY 1996 ram. It has over 460k miles on the original engine. It smokes, leaks, etc. Heads aren't an issue. My dad has a 5.9 ram with 200k miles on it and ill bet the heads are cracked. It runs great and he drices it every day. The magnum engine in my dart had cracked heads. I got a great deal on hughes EQ 2.02 heads so I swapped them out during a rebuild. The magnum swap can be very cheap. Reuse LA accessories, brackets, headers/manifolds, valve covers, engine mounts, etc.

The hemi is a much better choice if your wanting power. But it's also more money and doesn't look right in an otherwise original car, I think. Hemis can have lifter and cam issues, timing chain issues, etc. They aren't bullet proof either. And EVERYTHING has to be hemi specific. Accessories, timing cover, fuel pump, headers, engine mounts.... it all adds up!
 
And just for a example, I have a bone stock 5.2 magnum in a 71 dart, with a 904 and a 3:23 rear gear, that car gets 21 MPG on the highway, and runs about like a low compression 340 more or less.
 
@rumblefish360 - it was a Franks Racing Sidewinder Cam - can't find the specs but it was a mild cam that maintained the MDS system in the 5.7 and had some very good street manners while giving it a nice bump at the track.

I just want to make something clear - the only reason why I brought up the Hemi on my 300C as an example was just that as Example - I don't want my Dart (although it would be nice) to run 11s or 12s - but what I do want is to be able to jump in it and drive it whenever and wherever and if I want to take it and make a few passes as the local strip it would be able to handle that as well. "Reliability" with what I can only assume as a very nice bump in the HP/TQ department when going from a Slant 6 to the 5.9. Easily double in stock form (not including doing a Cam/heads etc). from the looks of it and all of you guys talking about going 300K+ mi then reliability does not seem to be an issue with these motors. Thanks for all of your inputs - I made an offer on that 5.9 - lets see where it goes.
 
Last edited:
The Magnum head cracking issue is definitely exaggerated. The deck surface is relatively thin and flexes a lot, and cracks often develop between the valves. The cracks almost never cause a functional problem, so if you get a good running Magnum engine you can do bolt-ons like camshaft and intake without removing the heads.
The only real concern with cracks is if you must have ported heads or if your engine has a damaged valve seat you would not want to dump money into those heads. That's when it's time to buy aftermarket heads.
Of course if the budget allows, definitely do aftermarket heads for the performance increase.
 
My '07 Durango has 160,000 miles on the hemi. No issues and if there are I have the Maxicare lifetime warranty. Already used it 3fold what it cost me new. They even cover the shocks.
 
@prican_2000 if you’re not looking to run 11s-12s and just wanting to be able to jump in your car and go wherever you want, if I were you, I’d do like BadAss71 did and buy a running/driving 2wd Ram and swap the 5.9, trans, fuel pump module, gauge cluster, wiring, etc. all into my car. And you could put another cam and eq or edlebrock heads on it for a performance bump and still have the benefits of fuel injection and an overdrive transmission.

Here’s a link to his build thread.
What have I got myself in to? Denver here we come!!

Oh, did I mention he got 25mpg Highway with this setup?

I had planned on going this route (and still might) but since I’m getting an HDK front suspension I’m seriously considering going with a 392 Hemi.
 
75slant6 said:
@prican_2000 if you’re not looking to run 11s-12s and just wanting to be able to jump in your car and go wherever you want, if I were you, I’d do like BadAss71 did and buy a running/driving 2wd Ram and swap the 5.9, trans, fuel pump module, gauge cluster, wiring, etc. all into my car. And you could put another cam and eq or edlebrock heads on it for a performance bump and still have the benefits of fuel injection and an overdrive transmission.

Here’s a link to his build thread.
What have I got myself in to? Denver here we come!!

Oh, did I mention he got 25mpg Highway with this setup?
Click to expand...

A freakin Great mention! And yes, even a small minor cam swap will still net you very good mileage. On a deal like this, you need not a big cam for a great return when your building a driver/cruiser. If you have ever driven a Durango, you'll remember for a heavy tub it moved pretty good backin the day. Often equipped with 3.55 gears, in your A body, the reduced tire size is like ading gear and the weight difference is big, sorry, I ment to say, BIG!
 
I would give up a lot to have the A500 overdrive in there, and to be able to run 3.91s. This gets you a starter gear of 10.73, and if you have never run this much starter, I can't tell you how much off-the-line snap this brings to the party.
And all your shifts are closer together, keeping your engine on the pipe more of the time
and it still cruises with a final drive of 2.70 so 65~2200 with 27s . This means you can still run a 268 cam no problem, on the hiway.And the Magnum has enough cylinder pressure to run that 268, and the TC is loose enough with 3.91s that you barely notice the soft low-rpm.
I would drop a stock Magnum truck combo into an A in a heartbeat with 3.91s, if I was looking for drop-in . You will be smiling for a good long time. It's a great starter engine, and a pretty good builder, meaning you can add on to it.
Make sure the 3.91s have a SureGrip!
 
AJ/FormS said:
I would give up a lot to have the A500 overdrive in there, and to be able to run 3.91s. This gets you a starter gear of 10.73, and if you have never run this much starter, I can't tell you how much off-the-line snap this brings to the party.
And all your shifts are closer together, keeping your engine on the pipe more of the time
and it still cruises with a final drive of 2.70 so 65~2200 with 27s . This means you can still run a 268 cam no problem, on the hiway.And the Magnum has enough cylinder pressure to run that 268, and the TC is loose enough with 3.91s that you barely notice the soft low-rpm.
I would drop a stock Magnum truck combo into an A in a heartbeat with 3.91s, if I was looking for drop-in . You will be smiling for a good long time. It's a great starter engine, and a pretty good builder, meaning you can add on to it.
Make sure the 3.91s have a SureGrip!
Click to expand...

The kitted A500 with the Magnum motor is a hoot for sure, but one thing I found on the OE Magnum heads was that even though the cracks didn't cause any problems the valves and seats were absolutely trashed.
I could see daylight between some of the valve faces and seats and this motor only had 98K on it.
Lower end looked fantastic.
EQ heads drilled for LA intakes, Hughes springs and retainers with factory rockers, Oregon Cam Grinders mild roller cam, A500 trans with stage 2 kit, headers, LA style accessories with OE V belt drive and a 26" radiator.
25 mpg hiway at 80-85 mph and reliable as can be.

Oh, and it took me three days by myself with no garage and on gravel. :D
 
TrailBeast said:
The kitted A500 with the Magnum motor is a hoot for sure, but one thing I found on the OE Magnum heads was that even though the cracks didn't cause any problems the valves and seats were absolutely trashed.
I could see daylight between some of the valve faces and seats and this motor only had 98K on it.
Lower end looked fantastic.
EQ heads drilled for LA intakes, Hughes springs and retainers with factory rockers, Oregon Cam Grinders mild roller cam, A500 trans with stage 2 kit, headers, LA style accessories with OE V belt drive and a 26" radiator.
25 mpg hiway at 80-85 mph and reliable as can be.

Oh, and it took me three days by myself with no garage and on gravel. :D
Click to expand...
Any idea what your exact combo makes for hp/tq and/or what it runs in a 1/4?
 
75slant6 said:
Any idea what your exact combo makes for hp/tq and/or what it runs in a 1/4?
Click to expand...

No idea on the 1/4 but it's built to drive the hell out of and has freeway gears in it.
Estimates during the build were around 350hp with my small dual plane and 600 carb.
An Airgap and a 750 Holley is supposed to put it higher, but that's not what it was built to do.
It was built with fuel economy, reliability in mind as top needs.:D

This was last year before it went in the car, and the last pic out on Route 66 a couple hundred miles from here after the swap.

5.9.JPG


A500OD.jpg


ShifterArt.jpg


73Swinger.jpg
 
Last edited:
TrailBeast said:
No idea on the 1/4 but it's built to drive the hell out of and has freeway gears in it.
Estimates during the build were around 350hp with my small dual plane and 600 carb.
An Airgap and a 750 Holley is supposed to put it higher, but that's not what it was built to do.
It was built with fuel economy, reliability in mind as top needs.:D
Click to expand...
So in your opinion, for a mostly streetcar (maybe see a drag strip a few times and hit some autox/road course tracks) would you recommend I do the full magnum swap like BadAss71 did (efi, gauges, hvac, etc) but build the motor up kinda like yours or do a bone stock, 485hp 392 Hemi and hopefully be able to get 22-25mpg? I do have an HDK front suspension coming so that’d make more room for either engine.
 
Honestly I think Hemi's are mostly a piece of jewelry and bragging rights engine, but fine if that's what a person wants.

That said, you could do all those same things to a Magnum driven car and save a shitload of money for other cool stuff.
A complete Hemi swap with the trans all the related details is a lot of time and money, and especially if a person needs to keep finances in mind.
I think I have about 3k into the entire swap and that includes the trans, yoke, converter, engine, cam and timing gear, valve springs, heads and fully automatic shifting system for OD and lockup.
I designed the shift system myself with pressure switches and solenoids so I can use only the normal three gears, or turn either OD or lockup on in auto mode and it shifts like the three speed with lockup or a three speed with OD, or a 3speed with OD and lockup completely automatically.
OD comes on at 60mph and lockup at around 75, and slowing down they both automatically disengage at those speeds on the way back down.

80 miles an hour at 2,100 RPM and exactly 25 MPG if you don't do 120.:D
(which is about where the cam starts into torque building, by the way)

I'm going to put a 3:55 8.25 rear end in it before long here because I don't need all that top end, and it'll just be more fun in town.
 
Last edited:
TrailBeast said:
Honestly I think Hemi's are mostly a piece of jewelry and bragging rights engine, but fine if that's what a person wants.

That said, you could do all those same things to a Magnum driven car and save a shitload of money for other cool stuff.
A complete Hemi swap with the trans all the related details is a lot of time and money, and especially if a person needs to keep finances in mind.
I think I have about 3k into the entire swap and that includes the trans, yoke, converter, engine, cam and timing gear, valve springs, heads and fully automatic shifting system for OD and lockup.
I designed the shift system myself with pressure switches and solenoids so I can use only the normal three gears, or turn either OD or lockup on in auto mode and it shifts like the three speed with lockup or a three speed with OD, or a 3speed with OD and lockup completely automatically.
OD comes on at 60mph and lockup at around 75, and slowing down they both automatically disengage at those speeds on the way back down.

80 miles an hour at 2,100 RPM and exactly 25 MPG if you don't do 120.:D
(which is about where the cam starts into torque building, by the way)

I'm going to put a 3:55 8.25 rear end in it before long here because I don't need all that top end, and it'll just be more fun in town.
Click to expand...
You’re right. I love the new Hemi’s but like you said, a huge reason I keep thinking about going with the Hemi is 1. That sweet 392 Hemi emblem on the fender and 2. I’d have a HEMI!! Lol

But like you said, the magnum can be done for much cheaper. I can easily buy a running/driving ram 2500 for 1200-1500, swap the engine, maybe the trans (might go T-56), all the wiring, gauges, HVAC, and the Dana 60 into my car and part out/scrap what’s left and get a decent chunk of the initial investment back. Obviously then I’d have to spend some money to shorten the rearend and hop up the engine but still, I think I could do the entire built magnum swap for around the price it’d cost to buy a 6.4/6 speed engine pallet from Cleveland Performance. The magnum swap is definitely the logical and rational thing to do. Heck, i need to start with just getting the steering column back in the car and get it running again!! Lol
 
TrailBeast said:
No idea on the 1/4 but it's built to drive the hell out of and has freeway gears in it.
Estimates during the build were around 350hp with my small dual plane and 600 carb.

An Airgap and a 750 Holley is supposed to put it higher, but that's not what it was built to do.

It was built with fuel economy, reliability in mind as top needs.:D


This was last year before it went in the car, and the last pic out on Route 66 a couple hundred miles from here after the swap.

View attachment 1715231709

View attachment 1715231710

View attachment 1715231711

View attachment 1715231712
Click to expand...
Sweet rodeo, with a semi tired 318 la ,the Flowmasters sounded NICE, whith the old school side exit exhaust .
How the new engine sounds ,with the side exit exhaust, intrigues me. My turbo muffler with turd downs shrieks worse ,than any horror movie .. You're thoughts?
 
I'm not TB
but my Dynomax 3-pass turbos with 3"rear-exit turn-downs, shriek like banshees from 5000 to 7000 at WOT. I love those wailers.
But the rest of the time are so mellow, so sweet, so quiet, that I hardly know they are there,lol. Best mufflers I've ever had. Except for one thing, 72 pounds is a lot of baggage to be hauling around on a day to day basis.................... so I pulled the fold-down rear seat out, and broke even. Nobody ever sat back there more than once anyway.
 
Abodybomber said:
Sweet rodeo, with a semi tired 318 la ,the Flowmasters sounded NICE, whith the old school side exit exhaust .
How the new engine sounds ,with the side exit exhaust, intrigues me. My turbo muffler with turd downs shrieks worse ,than any horror movie .. You're thoughts?
Click to expand...

The 5.9 sounds just about the same as the 318 did, but with a mild cam sound to it.
The Flowmasters I like because of like you said, the old school sound.
At 6k I have had women and kids freak.:D
 
TrailBeast said:
The 5.9 sounds just about the same as the 318 did, but with a mild cam sound to it.
The Flowmasters I like because of like you said, the old school sound.
At 6k I have had women and kids freak.:D
Click to expand...
Any issues with droning?
 
You must log in or register to reply here.
-

Back
Top