MagnumMPI swap - crank pickup fix?

[DionR]

I've been debating about some kind of MPI swap into my Duster (both Magnum and 5.7 Hemi). One problem I have been struggling with is the required crank position sensor in a Magnum swap and how to keep my 4 speed in the car and make it work.

Just noticed that the notes for the MPI kit that Mopar Performance has for the 390 hp crate motor notes that a flex plate P4876706, a Magnum flywheel, or a DUAL TRIGGER DISTRIBUTOR is required.

Search for pn P5153731 and read the text. It might say "available spring 2007", but that is related to the kit, not the distributor (I think). The current MP catalog I have doesn't reference spring 2007, so I am assuming it is related to the kit.

Not sure which distributor it is, but I know that the lean burn systems sometimes had dual pickups, but I also know that later on the TBI motors had a Hall effect pickup like the FWD motor 2.2/2.5 used. Not sure if it was a dual trigger or not.

My assumption is that with a dual trigger, the distibutor could be made to read the crank position for the computer. Don't know what (if anything) would need to be done to make it work, though. If possible, it would remove the need to figure out the crank position sensor on the back of the flywheel.

Anyone know anything about this?

I know the balance is different, so a complete motor swap would require dealing with that, but I am also thinking about swaping the top end and electronics on top of my numbers matching shortblock. I wouldn't have a roller cam, but the rest would be fine if I could figure out a crank pickup without having to change my clutch to a 143T setup just so I could get the tone ring on the back of the flywheel.

 

[DionR]

Spent some time scanning RockAuto.com and couldn't find a Hall Effect pickup with dual pickups. Only one with a dual pickup was the same as the typical electronic pickup, just two of them. Don't know if it would do the job or not.

 

[Keith Mopar]

I've been looking at this same thing. I think that flywheel P5249842 is the flywheel to use for thr conversion. it is the 10.5 flywheel for crate motors and will work with the stock crank trigger, but never could confirm that.
I never could figure out if this came with the tone ring or not.
I guess if it didn't that you possible could bolt a auto flex plate in behind. it would make the flywheel stick out an extra 1/8, not sure if that would hurt or not.

 

[DionR]

Not sure about the flywheel. The ones I've seen for a 10.5" clutch only really cover the balance issue but don't seem to have a tone ring.

I think the one referenced in the MPI kit is a 143T flywheel for an 11" clutch.

The dual pickup distributor was a special one off setup that never made it past the prototype stage.

There is a thread in the 4 speed forum with some pictures if you want to see how a flexplate works behind the flywheel.

 

[caferacerx]

mopar connection lists a 130 tooth flywheel for a 360 magnum "p5248942" and an alluminum one for the new hemi engines "p5153593"

 

[DionR]

mopar connection lists a 130 tooth flywheel for a 360 magnum "p5248942"

I don't believe it has the tone ring. It is for a Magnum 5.9 because it has the correct amount of inbalance, not because it will work with the MPI setup.

 

[billytuffnuts]

I don't know if I'm of any help but I have a complete magnum 5.9 intake w/sensors, fuel rail/injectors, throttle body, distributor, crank sensor and ignition coil taking up space in my garage I'll give you a good deal on if interested.

 

[Petzschler]

they were refering to the DUAL TRIGGER DISTRIBUTOR (a specialized distributor) which was experimental but never went into production. the lean burn distributor will not work.

 

[fenderman33]

Here's what I'm doing on mine so I could keep the 4 speed as well.
1994 5.2 Magnum w/ Megasquirt.
-Jon

 

[DionR]

Here's what I'm doing on mine so I could keep the 4 speed as well.
1994 5.2 Magnum w/ Megasquirt.
-Jon

That second image answers some questions for me. One idea that was tossed out to me by Ehrenburg was to drill holes in the crank pulley and use the stock pickup (after extending the wires, of course). Looks like that might work pretty well. Might need to file the holes square, and use the stock flexplate to get them in the right spot, but it sure looks good to me.

Hmmm....:-k

 

[caferacerx]

if it doesnt have the tone ring it would just be a 360 flywheel but they list it as a "magnum" flywheel curious has any one actually called them to find out?

 

[charger70]

I mentioned this on the 4 speed thread too. My friend has a 1996 5.9 magnum efi with full harness and computer in his 70 Duster. It also has the 833 fourspeed.
His solution was to use the manual trans flywheel for the Ram or Dakota 5.9 Magnum. All he did was to have a machine shop turn down the outside diameter to that of the LA (340)flywheel and then move the starter ring gear from the LA to the Magnum flywheel. The last thing is to drill the face of the flywheel for the pressure plate bolts.
Also you'll have to notch the bell housing to accomodate the tone sensor.
My friend is Duster7170 on here tho he doesn't post much, He'd rather do the phone thing. He'd be happy to talk it over.

If your already aware of this just ignore me. I didn't catch what your current short block is.
The magnums oil the heads thru the push rods and the LA oils thru a passage drilled thru the block and heads to the rocker shaft. so you'll need to switch to pump up lifters and hollow pushrods.

 

[charger70]

if it doesnt have the tone ring it would just be a 360 flywheel but they list it as a "magnum" flywheel curious has any one actually called them to find out?

The Magnum flywheel with out the tone ring is still Magnum specific due to the balance difference. But I believe is machined to LA dimensions so you can slap a crate magnum in a fourspeed car.
I was talking it over with my friend and we wonder if you could machine notches in this one for the EFI tone. Haven't seen one.

 

[DionR]

if it doesnt have the tone ring it would just be a 360 flywheel but they list it as a "magnum" flywheel curious has any one actually called them to find out?

Looking through the MP Magnum Engines book tonight, found that the notes for that flywheel say "carb only". So, pretty sure no tone ring.

 

[DionR]

I was talking it over with my friend and we wonder if you could machine notches in this one for the EFI tone. Haven't seen one.

I guess Red at McLeod gave up on building a 130T flywheel with the tone ring, so it doesn't seem like a good bet. Sounded like it was a problem with having enough room in between the clutch and the crank (or something like that).

 

[DionR]

I mentioned this on the 4 speed thread too. My friend has a 1996 5.9 magnum efi with full harness and computer in his 70 Duster. It also has the 833 fourspeed.
His solution was to use the manual trans flywheel for the Ram or Dakota 5.9 Magnum. All he did was to have a machine shop turn down the outside diameter to that of the LA (340)flywheel and then move the starter ring gear from the LA to the Magnum flywheel. The last thing is to drill the face of the flywheel for the pressure plate bolts.
Also you'll have to notch the bell housing to accomodate the tone sensor.
My friend is Duster7170 on here tho he doesn't post much, He'd rather do the phone thing. He'd be happy to talk it over.

If your already aware of this just ignore me. I didn't catch what your current short block is.
The magnums oil the heads thru the push rods and the LA oils thru a passage drilled thru the block and heads to the rocker shaft. so you'll need to switch to pump up lifters and hollow pushrods.

Yep, saw that you had talked about your buddy in another thread. I was (am?) hoping to sidestep the machining bill for that setup.

Also, I am going back and forth between a full swap or just dropping the top end of the Magnum motor on my numbers matching block so I don't have to find a place to store the motor. If I use my motor, I am missing both the roller cam and the mounts for the crank position sensor. Not having the roller cam I can live with, but the mounting tabs on the block are an issue.

Hey, any idea what kind of mileage your buddy gets? Don't remember if that was ever mentioned.

 

[charger70]

Hey, any idea what kind of mileage your buddy gets? Don't remember if that was ever mentioned.

He says 21.2 with 3.23 and BFG 295/50/15's. Likely a bit more with that big a tire.
This summer he swapped in an aluminum OD, and his mileage dropped to 20ish.
but with the 3.23's his rpm is so low at 55-60 that the engine is really lugging.
It's really great around 80 tho.
He just got a set of 3.91s for next year.

Its a bone stock engine with only a set of headers.

 

[DionR]

He says 21.2 with 3.23 and BFG 295/50/15's. Likely a bit more with that big a tire.
This summer he swapped in an aluminum OD, and his mileage dropped to 20ish.
but with the 3.23's his rpm is so low at 55-60 that the engine is really lugging.
It's really great around 80 tho.
He just got a set of 3.91s for next year.

Its a bone stock engine with only a set of headers.

Thanks!

Is it pretty fast?

 

[Keith Mopar]

Looking through the MP Magnum Engines book tonight, found that the notes for that flywheel say "carb only". So, pretty sure no tone ring.

I did phone and the gal (yup a gal) said it had the tone ring, but was still unsure. If it says carb only, I would think no tone ring.

 

[DionR]

I did phone and the gal (yup a gal) said it had the tone ring, but was still unsure. If it says carb only, I would think no tone ring.

I would be suspicious.

Per Brian Falzon at Mopar Performance Parts...

F.Y.I.

Red tried to prototype a flywheel for me. The problem was the spacing for the tone ring front to back. Still maybe worth contacting him, maybe he came up with something new.

From that, I would doubt they have a flywheel with a tone ring. Never know, though, wouldn't be the first time the right hand didn't know what the left had was doing.

 

[chryslerfat]

Here's what I'm doing on mine so I could keep the 4 speed as well.
1994 5.2 Magnum w/ Megasquirt.
-Jon

Any more detail if this will work and do the parts have to be fabbed or purchased?

 

[DionR]

Not sure if this is a fix, and the price is too high for me, but thought I would throw it out there. FAST EFI has a dual pickup distributor for the SB Mopar that might be usable to replace the tone ring.

http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=FS&Product_Code=305011&Category_Code=DistChrysler

The instructions mention plugging it into a cam/hall effect connector on the harness, so I would assume this is a hall effect pickup and would only require timing it correctly (in theory).

 

[fenderman33]

It will work with the megasquirt, but the trigger wheel and sensor won't put out the same wave form for the factory computer to understand what's happening.
I bought the trigger wheel and had the center opened up a little to fit on the crank pulley and then welded it.
The sensor came from digikey and I made the mounting bracket.
-Jon

Any more detail if this will work and do the parts have to be fabbed or purchased?