v-6 in early A-body

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my mistake for saying flywheel instead of flex plate, thinking OP's 833 while talking about Grissoms comment about 904 not working. Anyway...Kit, there is no need to apologize, here are more pics, flex plate on 5.9 and an old 6 cyl magnum flywheel from scrap pile, by looks of reluctor notches I would guess 4.0L Jeep due to weird spacing of trigger points, 3.9L would be evenly spaced as are 5.2/5.9. Sounds like you have a great understanding of ignition and injection. The Magnum stuff is pretty basic. PM or call if you have any questions about the factory injection.

59flex.jpg


junk.jpg
 
Thank you for the post of those pictures, they help me in many ways. I see the way the tone ring is situated just past the gear teeth. The V8 spacing is about 45 degrees because of the 8 square holes. Not sure the exact edges used for trigger (inside or outsides of holes), but it gives the timing window for subdivision used by the ECU timing control.

I am with you, use the magnum ECU and sensors, for simple unstall.
 
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modulated pulse width signal, quicker it spins the shorter the pulse. It actually measures the lost signal as window doesnt send pulse . Shows up as a reverse square wave on scope.
 
No to worry, the great information you have provided is very useful, and necessary for the v6 conversion.

I am the one at fault, and off topic.
 
magnummopar said:
I completely disagree with 98% of your post. ... never had a complaint about vibration. Third, your comment about loosing crank trigger is WRONG. ... There is some cross member modification to fit a 44/46 RE ... have you ever done the swap? Have you ever owned a magnum engine?
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98% disagreement sounds like bad math. My comments were just possible issues for the OP to read-up on. You gave much useful info for everyone, stop fuming.
A 60 deg bank angle V-6 is much more ideal. The V-6 Magnums used the same angle as V-8's, to keep factory tooling easier. The consensus I have read is that the V-6 Magnum was a temporary solution. Perhaps it continued longer because there were extras to use up.
If that crank sensor bracket you show is factory in Magnum engines, that makes it easy. I assumed one had to fab a bracket to work on a 904 bell-housing. "No", I have never owned a Magnum engine, only picked parts from them at a junkyard.
Custom-fabb'ing a new transmission tunnel in the car is a big bite for most, but does give a better transmission, and if the floor is rusted out it could be a two-fer solution.
While the 3.8L is a more optimal V-6 design, it won't bolt-up to a 904 (I assume), so would require using a Jeep 2WD transmission w/ probably the same custom tunnel mod's, plus one would be pioneering the engine controls. Is there something inherently different about the 3.8L that makes it a low performer? Mine has a modern intake w/ long runners, pushrods like a Magnum (and Chevy LS), but a coil-pack which is better than a Magnum but worse than current "coil on plug" designs.

The 3.8L "toner ring" slots are much different. Rather than 1 per spark, equally-spaced like the Magnum, it is a coded pattern of unequally spaced slots. It also varied over the years, which I found when I got the wrong one (~2003 w/ ~24 slots) for my 2002 (12 slots). The flex-plates suffered cracking (mine, see photo). Like the Magnum, the toner ring is welded to the flex-plate, which also has the starter ring teeth. The crank sensor is a shorter 3-wire Hall-effect type that bolts to a pad on my FWD tranny, don't know how they mount in a Jeep.

PICT0007.JPG
 
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The 3.0, 3.8 and the 4.0 are 60° v/6's. The 3.9 as well as the v 8's are 90° Engines.
 
My research of the V8 tone ring is 8 slots, that is two per cylinder, since four ignitions per revolution. The timing distance between slots is about 45 degrees, for advance control, and the other 45 degrees is time space outside advance control. Base timing hard set adds to total timing. Slot width is about 5 degrees. Base timing reference is not adjustable, because it is related to sensor location (bolted). The CAM (distributor) sensor must be adjusted correctly to index engine phase.

My interest in all of this is the ability to make a crank/cam sensor simulator for use bench in testing ECUs. I have made many simulators for all sorts of engines. It only takes me a few minutes to write the code, the hard part for me is to get the The timing wheel / cam shutter information and how they are referenced to each other. For about $3 a USB powered Arduno Nano can be purchased for use as simulator. The simulator ramps RPM up and down for test use in monitoring ignition coil signals and injector signals. Instead of coil and injectors, resistors are used and pulled up to 5V source, then an inexpensive logic analyzer is used to accurately measure signal timings.

On the V6, the ignition interval is 120 degrees with 3 ignitions per revolution, vs the V8 of 90 degrees and 4 ignition events. The 4 slots are at 20 degree intervals for an increased timing control range of 60 degrees. The 4 slots, result in less degrees to sub-divide in timing control, a V6 is less smooth in rotation, the multiple slots will improve timing control in the event RPM varies in the timing control window. The 4 slots provide near reference points, within 20 degrees or less to desired timing.
 
Boy does this have me thinking. The NV3500 would seem ideal on the surface, although it's pretty truckey. I wonder as well about fit. Anyone done it, and if so, what do you think?
 
Nv3500 is a good trans. Low first and 2nd gear to get it going. Top loader style, no rods to adjust. Make it fit and have a tough smooth shifting trans. With a 26" tire and that trans you could run a 2.76 gear easy, or 29" tire with 3.23 which is factory in my 3.9 dakota. 1900 rpm @ 70 and 20 mpg in a 4000 lb truck.
 
There's a handful of 6/manual/2wd Daks on my local online classifieds. For cheap. This project might be happening sooner than I thought
 
KitCarlson said:
I think it might be possible to generate the crank trigger signal from the distributor with the addition of a second sensor and trigger there.
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Mopar actually did develop something like this when they were working on the EFI kit for the 390 hp crate motors. The Mopar catalogs said something about a dual pickup distributor for manual transmission kits. I referenced it years ago in a post asking if anyone knew what it was. I asked Rich E. about it and he put me in touch with the engineer that helped him with the kits, and the engineer said it got dropped because it took some specialized equipment to get the distributor synced correctly.

I would worry about slop in the timing chain causing problems, too. I suspect that is why the original setup used a crank pickup.

KitCarlson said:
At the same time, the ignition could be done direct fire, coil on plug. I can use same hardware I am developing for the V8 COP ignition. I designed a similar system for 2.2L engine, and used the OEM ECU for timing control, diverted to coils. The reason would be easier drop-in eliminating crank sensor and bellhousing mod. The EFI trigger would come from my ECU associated with ignition.
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That would be slick. My only concern would be that slop in the timing chain would throw the timing off.

Really like to see someone develop a front mount crank pickup that would interface with the stock ECU. {{hint,hint}} :D
 
brad2v said:
There's a handful of 6/manual/2wd Daks on my local online classifieds. For cheap. This project might be happening sooner than I thought
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Brad, 3.9V6 Daks use an AX-15 trans. To get an nv3500, you would need to find a 5.2V8 2wd Dak. The way you tell the difference between the two is AX-15 has bellhousing that unbolts, 3500 is one piece, also AX-15 has 22mm bolt for drain and fill while nv3500 has 17mm allen wrench drain plug.

DionR said:
That would be slick. My only concern would be that slop in the timing chain would throw the timing off.

Really like to see someone develop a front mount crank pickup that would interface with the stock ECU. {{hint,hint}} :D
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Dion, If you run a high quality timing set like the Pro Gear we sell, you wont have any issues at all, 500+HP with no issues. The front mounted crank sensor seems like a waste of time since the crank sensor works great as it is, if you want to use magnum on a-833, there is a 134 tooth flywheel with correct reluctor available and a magnum flex plate works on a 904/727.
 
[QUOTE="BillGrissom, post:"98% disagreement sounds like bad math." your post was 200+ words, I agree with 4, "it bolts to 904" 200x.02=98%
" The consensus I have read is that the V-6 Magnum was a temporary solution. Perhaps it continued longer because there were extras to use up." Alpar being your source? "Perhaps" would infer you are guessing.

"If that crank sensor bracket you show is factory in Magnum engines, that makes it easy. I assumed one had to fab a bracket to work on a 904 bell-housing. "No", I have never owned a Magnum engine, only picked parts from them at a junkyard." Assumed indicates you dont know, yet you are giving advise to somebody?

"While the 3.8L is a more optimal V-6 design, it won't bolt-up to a 904 (I assume), so would require using a Jeep 2WD transmission w/ probably the same custom tunnel mod's, plus one would be pioneering the engine controls. Is there something inherently different about the 3.8L that makes it a low performer? Mine has a modern intake w/ long runners, pushrods like a Magnum (and Chevy LS), but a coil-pack which is better than a Magnum but worse than current "coil on plug" designs."
More assuming, the NSG370 6 speed is larger than an nv3500, expensive $1500-$2000 used, and has a 4.45 first gear as well as 4.0 reverse, not a great choice for car. You again state "fact" that a coil pack is better than bomb proof Magnum ignition, which is the 3.8's Achilles heel, with common failures and not up gradable like magnums .

"The 3.8L "toner ring" slots are much different. Rather than 1 per spark, equally-spaced like the Magnum, it is a coded pattern of unequally spaced slots. The flex-plates suffered cracking (mine, see photo). Like the Magnum, the toner ring is welded to the flex-plate, which also has the starter ring teeth."
Again, even though I posted a pic clearly showing the flex plate as one piece without a starter gear, you state "fact" "like the magnum, the toner(tone) ring is welded to flex plate, which also has the starter ring teeth(ring gear)"....which is clearly incorrect.

You accused me of "fuming" which I was not doing, I just pointed out that most of the "factual info" you gave as advise was dead wrong. I spend 1/2 of my day taking calls from people that got their "facts" off the internet and correcting incorrect information about Magnums. I do take offense to people posting total bullshit about something they know nothing about. If you dont know what a factory crank sensor looks like, you have never looked past the valve covers on a magnum while pulling "left over parts" off ram vans. The thought of putting a 3.8 in an A body is completely ridiculous as the pcm is not swap friendly, it would be total fab job, much harder than tunnel mods to install 44RE, there are no motor mounts, trans has dump truck gear ratios and they were just not a great engine. No matter how you slice it, its a mini van engine and would be a nightmare to install or wire pcm to actually run. On the other hand, you can buy a whole Dak 3.9 for under a grand, it bolts in with $150 mounts, uses V8 radiator, parts available at 7-11, it bolts to 904(your moment of truth), harness is available for $500 plug n play and they are a fun economical bomb proof engine with a ton of aftermarket upgrades for cheap.

I dont know or care what you do for a living but I build magnum vehicles and I dont go on dentistry forums and tell people how to do root canals or crowns because I dont know anything about dentistry other than it hurts and its expensive. I could assume you just cast a tooth mold in stainless or gold and then glue it on but I am sure not going to tell posters that on the dentistry-help forum.com
Please stop giving info on subjects you know nothing about(magnums). The OP wants to install a cheap easy V6 in his early A and the 3.9 fits the bill to a T.
BTW My 1.8L Audi makes more power and torque than you minivan but I would never consider putting it into an A body and if your 3.8 mini van impresses you, you need to drive some more cars, perhaps a 3.9 2wd Dakota so you can then give an opinion based on experience.
:soapbox:
 
My 2003 2wd dakota with 3.9 uses a nv3500. That is factory. They quit using the ax15 sometime in the mid to late 90's. I just changed the clutch in mine at the beginning of the year, yes my trans is a one piece, not a two piece with removable bell housing.
 
racerdan, you are correct, the ax-15 was only used through 99 and possibly some 00's, the same time they switched in TJ Wranglers.
 
Yup, I'm a Chryco parts schmuck, I had a look, '99 was it for the AX, '00 up were 3500's.
 
magnummopar said:
Dion, If you run a high quality timing set like the Pro Gear we sell, you wont have any issues at all, 500+HP with no issues.
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Not talking about issues with the function of a timing set, only that I see the small amount of slop in any chain causing fluctuations in the readings. I just don't think you can depend on the relationship between a camshaft and a crankshaft connected with a chain to remain consistent revolution after revolution, regardless of the quality of the chain. Makes sense if you want to know which half of the cycle you are on, but not if you want to know exactly where the crank is in it's revolution. Works great for an old school timing setup where it doesn't make much difference, but not in an EFI setup, in my opinion.

magnummopar said:
The front mounted crank sensor seems like a waste of time since the crank sensor works great as it is, if you want to use magnum on a-833, there is a 134 tooth flywheel with correct reluctor available and a magnum flex plate works on a 904/727.
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I agree that the existing one works great, but up until a flywheel was introduced there was no option for keeping the 4 speed without going to a big 143T flywheel, and even now with your flywheel there is one big reason to want a front mount sensor - I already own a functional flywheel that is matched to my motor. Hard to see a good reason to spend money on something new, if I can find a way to get where I need to be without throwing away what I have. If I was starting over, or didn't already have what I do, then yes it makes complete sense to phone you up and ask for a price since I can't find it on your website :D (not a dig, just a comment). And maybe in the end it will makes sense to buy a new flywheel, but I don't plan on doing that until I have exhausted all my options.
 
Dion, technically it would be the cam that gets the sloppy reading since the crank sensor reads off the crank mounted flex or fly and the cam sensor reads off the distributor via cam via timing set. If you use a scanner to set cam sync, you can read the cam position and watch it while engine is running and I have never seen more that 1-2 degree fluctuation and that was on a 150K with really bad timing set. When you set sync, you do it at 1500 RPM to remove the slack since a bit of fluctuation at idle wont affect anything.

I do agree that in your case, a front crank sensor would be very handy but probably more $$$ than the flywheel. MSD wont work(made in china) unless you run aftermarket pcm, which in over 500 HP is probably a better idea anyway. MS Pro would be my choice but its not plug n play or user friendly. In the end its just building cars and what works for each individual application. :D
 
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magnummopar said:
Dion, technically it would be the cam that gets the sloppy reading since the crank sensor reads off the crank mounted flex or fly and the cam sensor reads off the distributor via cam via timing set.
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Exactly my point. If someone used the distributor to read both the crank and cam position, you would get a sloppy reading for both.

magnummopar said:
MSD wont work(made in china)
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More than just an issue with the location of the manufacturing plant. The MSD stuff (last I looked) is a flying magnet style and gives a different type of reading than the OEM Hall Effect pickup. Plus it only has 4 magnets, as opposed to the 8 notches in the OEM setup. Far as I know, there is no off the shelf aftermarket crank sensor that uses a Hall Effect pickup, but I haven't looked in a while.

Knowing my track record, a custom crank pickup will end of costing me more than a flywheel, and I wont figure it out until I've spent too much money. Some guys never learn. :BangHead::realcrazy:

:lol:
 
No worries, found it on your website even without the link. I figured out what I was doing wrong, and there it is! :)
 
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