5.2 Magunum into J Body advice needed

[Bruceynz]

Hi Guys,

Ok I know all the info I want will be on this website but I don't have time to trawl through all this info in a short time, a 5.2 Magnum has come up for auction here in NZ which doesn't happen often, I need to know how hard is it to swap into my J body, here is the add for the engine.

"1997,Dodge Dakota 5.2 magnum motor and auto 209k miles,exellent running condition,shifts perfectly,fitted with mopar M1 intake and holley throttle body,engine still in truck,can be run or test drive."

Will the engine all bolt up to my 904 all ok and what torque convertor should I use? My one or the one on the engine?

What is the M1 and Holley throttle body, is it performance? Is that EFI intake or can I put a carb on it? If its running a holley throttle body does that mean it has after market computer?

What is the biggest roller cam I can run on this engine with stock convertor as I know nothing about rollers and what will work. I know I had a discussion about a 360 a we while ago and there was holes to be filed out and certain things had to be done with the balance.

Thanks
Bruce

 

[brotherGood]

It'll mount up..I think it uses the same converter, not 100% though.

If you can get the pump and computer for the mpfi, use it..if you're just getting the engine, pull the intake and throttle body and swap out for a carb. Can't answer much regarding the cam, but IIRC, the springs are weak on these..meaning you can't go much further without float. Stiffer springs though will fix that problem.

 

[Monkeyed]

I would use the flexplate on the magnum just in case, I think it's externally balanced anyway, but I don't think you need to use that convertor. pretty sure it'll bolt up to the same trans and motor mounts as an LA v8. If you're going to run the fuel injection make sure you get all the wires/sensors/computer(s) with it. For a carb, I believe, the intake bolt angles are different but can be drilled to make work.

was looking at some options for this on my m-body, keep us posted on how it goes if you decide to go thid route

 

[Monkeyed]

It can be kind of tough knowing what you need and don't need under the hood, or hidden under the dash to retro-fit efi, I've been looking for more or less complete wrecked trucks that still run so I'd have it on hand if I found I needed something from it

 

[80mirada]

5.2 is internally balanced, should be able to use the flexplate unless it is a 96 up. A manual transmission controller would work, just need to figure out the fuel pump.

 

[kkritsilas]

Brucenz:

A great site for this is here: http://www.magnumswap.com/

Your A904 should hook up fine. Use the same torque convertor you have now, unless you have a reason to change that over.

Keep in mind that Magnum heads are prone to cracking between the intake and exhaust valves. Doesn't mean that the heads are bad for sure, just that they MAY be bad. It is a known issue with the Magnum cylinder heads.

The M1 intake manifold is a performance part. The Holley throttle body is a little harder to figure out, can't say without looking at it wheter it is the full Holley aftermarket EFI system, or if they have screwed around with hooking up the Holley throttle body to the factory computer. You will be able to figure that out by looking for the Holley computer; if it is there, then the full Holley EFI system is in place. This is actually, to me, preferrable to the factory computer, as the Holley will be much easier to adjust. Assuming this is the case, you will need an electric fuel pump to raise the fuel pressure to the point where the Holley EFI will work properly, along with the associated fuel lines. Information on this should be on the Holley web site.

Also, you will probably need to swap out the oil pan with the one you have now. This is also on the magnumswap.com web site, as well as some other notes regarding header clearances, requirement for a mini-starter, etc.

Kostas

 

[Aspen500]

They came from the factory with throttle bodies made by Holley. My '96 Dakota with the might Magnum 3.9L has Holley cast into the t.b.
There are carb intake manifolds available for Magnum engines and a regular distributor will work also (far as I'm aware anyways).

 

[Bruceynz]

Well i was planing the XXX714 heads (same as XXX302) sum 6900 cam, performer intake and Holley carb on my 1983 LA engine, but then this mag has showed up for sale here in NZ, my engine is rated at 120hp and the 318 mag was rated at 230hp out of the box, all my mods won't even get me to that power output of the factory magnum, hmmmm I have new engine mounts at home, new distributor with orange module, the mag engine has a mopar M1 intake which looks like is 4bbl carb intake so all I need to do is bolt carb on hook distributor up, use my TQ converter and trans. Not sure but think I will need a different sump for a car????

 

[brotherGood]

As far as the pan goes..you need a 360 car pan.

 

[jasperjacko]

I don't believe the 360 pan will work on a 318.

 

[brotherGood]

The magnums used a 360 design. Since they only came in trucks, you're left trying to find a 360 car pan to fit the car, and the magnum

 

[jasperjacko]

They have the bigger crank journals ?

 

[Bruceynz]

So is there a pan that will fit a 318 that will allow the engine to fit into a 83 cordoba? What should I look for on ebay?

 

[jasperjacko]

I'm sorry, I don't know much about the magnum motors. I know the LA motors 318/340 can use the same pan, but the 360 has its own pan.

 

[kkritsilas]

The problem is not whether a 318 LA pan will fit a Magnum 5.2L, the problem is that Magnums only came in trucks. Trucks use a rear sump oil pan, cars use a center sump oil pan.

From the magnumswaps.com website:

"Oil Pan
To install a Magnum motor in your car, you will need a car-style mid sump oil pan and matching pickup tube. All Magnum motors have rear sump truck-style oil pans. If you’re putting the Magnum in a truck or SUV, the existing pan will work.
The Chrysler LA 360 oil pan will bolt-up to the Magnum with no modifications, but you aren’t stuck with the typical leaky four-piece 360 Gasket. The Magnum uses a one-piece oil pan gasket. If you use the Magnum timing cover, you can use the gasket as-is. It is possible to use the Magnum gasket with the LA timing cover, but modifications to the front of the gasket are required. Details here: Oil Pan Gasket"

So what you need is a passenger car oil pan for a 360. Use the Magnum oil pan gasket, or replacement oil pan gasket for a Magnum.

 

[Bruceynz]

So these bits are what I need for the 5.2 magnum to fit a car?


http://www.ebay.com/itm/71-80-Chrys...ity-/350889784458?hash=item51b2a9348a&vxp=mtr

and

http://www.ebay.com/itm/New-72S4-El...ars-/321714562725?hash=item4ae7aea6a5&vxp=mtr

 

[Bruceynz]

Can anyone verify that the above parts is what I would need to get it to fit in?

 

[brotherGood]

I'd just order a new pan/pump from a parts store for like a 360 duster or something.

If using a mechanical fuel pump..you need a snout extender. I think Mancini sells them

 

[aspen77rt]

Hi Guys,



What is the biggest roller cam I can run on this engine with stock convertor as I know nothing about rollers and what will work. I know I had a discussion about a 360 a we while ago and there was holes to be filed out and certain things had to be done with the balance.


Thanks
Bruce

Hood clearance might be a factor. If that is the stock Mopar OBD 2 the first hurdle is hooking that up. Not impossible but..... Second hurdle is that is an Speed Density system, so you would have to flash the PCM for most engine upgrades. If not you will be limited on your cam.

You need to hook up a efi fuel pump, either in-tank or external and run new fuel lines. O2 sensors need to be put in.

However, far as a cam, you also need to consider stock heads or aftermarket, valve springs, possible PTV clearance, Head flow, compression, rear gear, etc...

However the cam should be the last piece of your combination.

http://www.hotrod.com/how-to/engine/ccrp-0403-roller-cam/

Easiest would be to strip the PCM stuff, carb intake and carb, new flex plate, and electric FP.

Hydralic Roller cam= no cam break in.