Street Lethal

iTrader: (16)

This thread is going to chronicle how to convert your existing HEI (High Energy Ignition) system over to the GM DIS (Distributorless Ignition system) to be used in conjunction with the EBL-P4 by Dynamic EFI. The DIS system is what we refer to as a "wasted spark" system in that it essentially fires two sparks at the same time, with one of the cylinders being at its' compression stroke, and the opposing cylinder in the firing order being at it's exhaust stroke, thus the system wasting energy on that second cylinder that is creating no combustion. However, the amount of spark wasted though is minimal, and by the time that same second cylinder reaches its' own compression stroke, it is fully charged and ready to go. It is also system that employs a sequential type firing system, which ideally will pulse once injector at a time when signaled, but for the time being, this particular conversion will be remaining in batch fire mode during its' beginning stages...

Now, the GM DIS system in its' entirety is made up of the following parts; a crank trigger (also called a crank ring) with dual crank sensors, a camshaft sensor, and an Ignition Module with four coil packs. You can use your existing spark plug wires and spark plugs. The Ignition Module in itself in the "brain" of the system in terms of its' spark signal, and it was specifically designed to know when, and where, to fire its' spark utilizing the information being received by way of the crank trigger and crank sensors. The Ignition Module would then use these signals to fire its' spark, while then using the related camshaft sensor information to tell the ECM/PCM when to fire the corresponding fuel for its' sequential type firing system. But again, we are staying batch fire for the time being, and will not be utilizing a camshaft sensor at this present time...

This thread will show you how easy it is to, not only install the system, but "create" a heavy part of it. The parts I am using for this conversion are as follows...;

* Northstar Ignition Module with bracket...
* MSD Coil Packs, DIS 4 pack...
* Custom crank trigger wheel...
* Two crank sensors w/custom location bracket...

The wiring diagrams will be provided when we reach that stage, and plenty of pictures and videos will be provided documenting the how's and the why's. The two key areas of this conversion (you may choose to do it another way) is creating our own crank trigger wheel, as well as crank sensor brackets. The wheel itself needs to be dialed in very carefully to work with the Northstar Ignition Module, and the brackets need to keep the crank sensors in a very crucial position. But more on that when we get to that point...

More soon...

Tuned Performance

iTrader: (92)

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Street Lethal

iTrader: (16)

The vehicle I am using for this conversion is my '90 Pontiac GTA. Some may remember it when I converted it over to the EBL-P4 system, as well as when I turbo charged it. The 305 served as an engine to be used to essentially mock everything up, and I will again use the same 305 to serve another purpose for this conversion. Awhile back, I removed the stock oriented small cap distributor from the engine, inverted the ECM wires, and hooked up a large cap MSD HEI cap and rotor, along with a Pertronix Flamethrower coil. The system served me very well, and it still was serving me well up until this point when I decided to go distributor-less...

Street Lethal

iTrader: (16)

Now, for the first order of business, and the toughest to boot, the crank reluctor ring. The stock Northstar reluctor ring is very large in its' diameter, in fact a little too large and in the way residing underneath the waterpump housing if you ask me, so, we are going to re-scale the original size to a much more adequate size that we all can work with. Doing this will not effect the unique and distinctive notch signal, it will remain in tact, albeit with a shorter degree. In the picture I posted above, you can see that I am currently using a serpentine belt system to drive all of my accessories, and I would very much like to keep this system due to the ease of changing belts. However, this conversion can be done whether your running a serpentine setup, or v-belt setup. The stock crank pulley for the serpentine system only has one large space for the one belt, which is something that is of absolutely no use to me. So, I got my hands on a crank pulley from an earlier v-belt system, but the one I needed was from a v-belt system that had the same size groove for its' alternator belt. This in turn allowed me to maintain my serpentine belt system, while having an "unused" groove behind it, unused of course... until now.

More soon...

MoJoe

iTrader: (5)

Problem with the V-serpentine pulley... the multi-rib part is only 5 ribs, vs 6 ribs for the full blown serpentine system.

Street Lethal

iTrader: (16)

Good point, although that part was already taken care of, and was going to be explained when making the notch cuts into the pulley. The engine has already been running with the v-belt crank pulley for quite some time already. This thread is chronicling the process of the Northsar DIS conversion which has been contemplated for awhile, not when I created the thread. There really is no problem with the v-belt pulley, it just requires a different serpentine belt pattern using the same length, which ideally is still much better than a skinny v-belt that are prone to flipping over at higher RPM's, not to mention 5-6 groove serpentine belts being a breeze to replace...

Tuned Performance

iTrader: (92)

Im not sure if this helps to start making a schematic with. I look at it but couldn't figure out if the four wires that use to be for the hei icm went to the 6 connecter plug with the crank pickup.

Street Lethal

iTrader: (16)

Compare the seven pin HEI wiring w/the N* DIS, and we have as follows...;

HEI 7 Pin ICM (Four From The ECM);

* EST (Electronic Spark Timing)
* Reference Signal
* EST Bypass 5V Out
* Ground

Northstar DIS ICM (Excluding Cam/Fuel);

* Ignition Control
* Reference Signal
* Bypass
* Ground

... I excluded cam/fuel because I am staying batch fire.

Orr89RocZ

iTrader: (20)

Interesting. Curious to see how this turns out. Is it any better than doin the 411 with ls1 24x stuff, or if ebl can be configured to handle 24x stuff, whats the advantage with DIS?

Tuned Performance

iTrader: (92)

I'm not sure if this statement would be correct, besides a clean looking engine bay, the dual coils would stay cooler and may produce a hotter spark, the timing would change as a timing chain stretches.

Street Lethal

iTrader: (16)

When maintaining the batch fire system, it seems to be a very straightforward conversion. To be quite honest, other than what TP pointed out above, there really isn't that much of an advantage of DIS over HEI, other than maybe a less heat prone coil pack system and cooler looking engine bay. It really is a basic swap, but a swap that will set the EBL-P4 users up for something that is inevitably coming. I'm going off course though. When I grabbed that crank pulley to create a crank reluctor ring for the Northstar DIS conversion, I also grabbed a sacrificial fat cap HEI distributor. We'll nickname him "stubby" after we get through cleaning him thoroughly, as well as chopping him down to a stump...

Tuned Performance

iTrader: (92)

No cap and rotor to maintain and it looks cool

Street Lethal

iTrader: (16)

Which/who's statement were you referring to?

Tuned Performance

iTrader: (92)

Post #9 reply to orr89rocz

Dominic Sorresso

Does the N* DIS take a cam signal and would post pics of harness connections necessary?

Street Lethal

iTrader: (16)

Dom, yes. The Northstar takes a cam signal. It is essentially the same ignition system as the HEI, but with three additional wires leading to the PCM. Two of them are for the camshaft sensor (24X & 1/2X CAM), and since I am staying batch I won't be using them, but I will use one of them as an RPM lead for the tach though, I would need to. The third is the B+ (power) which goes to directly to the PCM with the Northstar, but the HEI of course has its' B+ (power) wire next to the tach signal wire and is switched 12 volt...

Dominic Sorresso

SL,

Of course the LT-5 has its own DIS which operates in WS. I am following your project because the N* DIS is more plentiful than the LT-5. Our ZR community needs an alternative. So looking to see if this may be one of them, even if the EBL is piggybacked to our ECM. I KEEP BEGGING RBob to do an EBL for our cars but so far no joy. ��

Street Lethal

iTrader: (16)

Haha. I was on him to do something for the $EE for awhile myself. Although this swap might just allow for the 94/95 Corvette guys to use EBL-P4 Flash now too, would just have to add the crank reluctor ring and sensor. Maintaining the optical sensor for SFI is another story. But I digress. Almost finished with the stubby distributor, before I start the crank pulley I need to show something first in case some of you guys reading do it the very same way...

Dominic Sorresso

I picture RBob as standing in the background teeheeing as we crawl across the floor imploring
The Wizard of Tune. 😊
I respect the heck out of him. And he's a nice person too.
I'm looking forward to reading ur write up.

Street Lethal

iTrader: (16)

Okay, stubby was scalped, polished and is looking very purty...

Just need to make him a cover w/gasket and tap four small bolts in (downward), easy...

Street Lethal

iTrader: (16)

Okay, I have to show how I am modifying the dummy distributor in case anyone elects to do this the very same way. Inside the head of the distributor that was cut off you will find a sleeve in which the shaft uses to keep itself stable. This sleeve is very short in length, and it pops right out. You need to reuse this, albeit your relocating it lower on the housing. The sleeve doesn't just slide in though, your going to need to drill the housing a tad with the right drill bit. Do not drill too wide, it needs to slide in and fit snug, no wiggle room. This allows the modified shaft to remain stable. Now, you will need to find a small bolt with a washer wide enough so that it does not pass through that sleeve (see pic, in between sleeve and shaft). We're going to drill the center of the shaft by making a "punch", then drilling nice and straight. The shorter the bolt, the less you need to drill and tap, so remember that. This will keep the shaft and housing as one unit, other wise when you pull the housing, the shaft would obviously stay in place. Last but not least is the cover, which is not seen in the pic. It is basically a metal cover that fits the base of the housing perfectly (not the base that gets secured by the distributor hold down clamp, the new base around the sleeve's new orifice where you made your cut). This is why you want a washer no greater than the sleeve, it allows you room to work with when you drill and tap around the sleeve area. This metal cover has four holes drilled "through" it at 12:00, 3:00, 6:00 and 9:00, and will be secured to the housing with four small bolts and a light coat of gasket maker. Be sure to smooth that new surface flat before you start drilling and tapping. I'm going to anodize mine to make it look pretty in the end, but you of course can do whatever you want to with yours...

zz17iroc

iTrader: (4)

Street Lethal, this is very interesting. You know I'm a supporter of EBL P4. I think it's great for the money and it works, I can't wait to see what RBob has in store for EBL users.
Keep up the good work and I'll subscribe for sure.

Dominic Sorresso

Is the use of a modded dizzy necessary for your upgrade? No provision for dizzy on LT-5.

Street Lethal

iTrader: (16)

Unfortunately yes, as the lower gear of the distributor is turned by the camshaft in which drives the SBC oil pressure. I considered using the short drive from the LT1 engine, but that one gets bolted to the engine underneath the intake manifold, and I don't want to encourage members to drill and tap in the oil valley. Plus, I may just use the top of the modded dizzy for something else later on...

Dominic Sorresso

Bummer.

antman89iroc

How about us EBL Flash users (not P4)? Will the same system work albeit with different harness connection locations.

Street Lethal

iTrader: (16)

Absolutely, I just titled the thread P4 because that is what I am running, but it will work with both EBL products. Just like with an HEI system, the computer advances timing. Pull the computer and the HEI defaults to base timing. Nothing has changed. The only difference with the Northstar DIS system is that the Ignition Module follows a very distinct reluctor pattern to know where the crank is in relation with the cylinder, and the Ignition Module was also engineered to control its' own dwell, efficiently...

Street Lethal

iTrader: (16)

Just a small update. The dummy distributor is pretty much done, just need to anodize the cap I made and I will throw up a picture of it installed. I am now going to start working on the crank pulley reluctor, and the crank sensor(s) bracket. This is where I needed to explain the process before you start grinding the notches. First and foremost, when you rescale the actual size of it, as was explained by RBob, be sure to convert inches to angles first to verify, don't just go on a picture that was reduced in size then start drilling and cutting. Also, locate where TDC will be in the reluctor, and when you figure out where you want your TDC to be facing, be sure to bring the engine to TDC with balancer first, note the pattern of the three bolts that bolt the pulley to the balancer's location, and then cut your notches with TDC facing the area where your making your crank sensor bracket. This just makes it easier to locate TDC in the future. My location is going to be on the passenger side of the block where the smog pump used to reside. I am using two old brackets to accomplish this, they will be modded substantially (cut, welded, etc.), cleaned thoroughly, then painted. The main bracket is slotted to allow for some adjustablity, see the two pics of the main bracket below. This bracket will get bolted to the lower water pump bolt on the passenger side using the bolt hole to the right of the slot, and "wrap around" the balancer and pulley. The rest of it will be cut off, and then another bracket will be welded to it and secured to the front mounting bolts on the block. So basically, the bracket itself will have three strong bolts holding it in place, with the crank sensors bolted to it via the adjustable slot...

First pic shows the bracket, second pic shows its' direction bolted to the water pump...

anesthes

iTrader: (12)

Rob,

I know you are fabricating your own crank reluctor and sensor bracket, but I was curious if someone sells a 'kit' for SBC ?

-- Joe

Six_Shooter

iTrader: (2)

I wouldn't be surprised if the Northstar ignition system couldn't be swapped in place of the LT5 system, since IIRC the signals between the ECM and ICM are teh same for both systems. There might be a 10* difference (in relation to crank timing) in EST signal that can be accounted for pretty easily in the tune.

The hardest part and this goes for any Northstar ignition conversion is the trigger wheel and sensor brackets.

Dominic Sorresso

SS,

The LT-5 module also controls dwell which is what complicates things. Plus, I believe the LT-5 was the only motor using a 9 slot reluctor cast in the middle of the crank. The reference angle on the LT-5 is 6*.
So far the potential solutions likely require a reluctor mounted on the nose ( although I like the stability of a reluctor in the middle of the crank) using some form of piggyback ECM FOR IGNITION, or some device that can convert the native LT-5 crank signal to use w CnP or COP. So far nothing like that around.

Six_Shooter

iTrader: (2)

The LT5 ICM works exactly the same as the (60 degree) V6 and I4 (2.0/2.2L OHV) DIS, where the signals between the ICM and ECM are concerned. There are just 2 extra notches on the reluctor wheel for the LT5, and the Northstar module has been used with code that has also been used to run the V6 DIS ICM. This is why I'm confident that with a trigger wheel and sensors mounted on the crank pulley in the Northstar configuration, that the Northstar ignition system could be adapted to the LT5.

The base timing of the Northstar system seems to be 10*, but there's an addition 70* (or there abouts) of timing required in the EST signal to get proper cylinder firing as controlled by the ECM, I'm not sure what this offset is for the LT5, but I imagine it is similar, or could be closer to the 60* offset that the previously mentioned I4 and V6 DIS ICMs use. The 3800 DIS ICM uses a 30* offset, just FYI.

There's nothing wrong with a crank pulley mounted trigger wheel. I have used this setup on 3 engines now for a total of about 9 years of use. One of those vehicles was driven year round, and one is driven almost year round.

There is a module that is available through an Australian contact that is touted as being a "universal ignition module" (programmable), but it's not needed for this case, and would only complicate things overall, due to how the Northstar ICM reads the signals. It was designed more for using Delco ECMs with non GM engines, or being able to convert crank signals to use with other modules. I just don't know that the LT5 trigger wheel to Northstar conversion is a possibility.

Dominic Sorresso

SS,

Actually I have been discussing that "universal IM" the person from AUS. Purportedly it can read multiple reluctors and provide a signal for firing CoP or CnP.
The crank signal for the LT-5 goes to the ICM, so my understanding is that its the ICM that dictates dwell and the firing order. ECM provides timing and fires the proper injectors. The ICM in the LT-5 has a 14 pin connector similar to the Buick V6 modules. Can this be duplicated w the North*?
Appreciate any additional insights and thoughts you may have. The ICM is a critical path in maintaining the LT-5. Its mil-spec and very robust but its also 25 years old. We need an alternative.
Sorry for hijacking your thread SL.

Tuned Performance

iTrader: (92)

http://m.ebay.com/itm/121471842443?nav=SEARCHA little more code info and reluctor info to add to this topic.
http://www.mastercraft.com/teamtalk/....php?p=1090285

https://www.thirdgen.org/forums/diy-...y-dizzy-3.html

anesthes

iTrader: (12)

That's expensive.. $200 core charge?

-- Joe

Tuned Performance

iTrader: (92)

No doubt neat bracket to copy with a non serpentine setup.
This is the best deal I found on the crank position sensor.
Another style that was use I'm not sure if shorter L31 pickups would work I don't see why not reluctor size dependent.
http://mcpartsdepot.com/collections/indmar?page=29

Tuned Performance

iTrader: (92)

I don't see the mention of metal expansion end play of atleast .015 . I'm sue a wheel bearing cap or expansion plug upside down could be used as a oil pump drive cover . The shaft instead of drilling and taping a roll pin or a grove for a snap ring could be used a well. Just throwing out ideas.

anesthes

iTrader: (12)

The snap ring is actually a good idea. I was going to weld a washer to the top of mine after setting end play but machining a groove in it for a snap ring would allow it to be taken back apart if needed.

-- Joe

Dominic Sorresso

One question that comes to mind when installing reluctor on the crank. Unless you're machining the notches onto the pulley or balancer, or installing reluctor onto end of pulley stack, what happens to serpentine alignment with reluctor sandwiched in between balancer and pulley?

anesthes

iTrader: (12)

Your pulleys go out of alignment by the thickness of the reluctor.

On my DIS swap, I opted to turn my balancer down by the thickness of the reluctor.

The kit I bought came with a spacer for the water pump and alternator, but it seemed to make more sense to me to modify the balancer. 20 minutes on the lathe to turn off 1/8".

-- Joe

Dominic Sorresso

Joe,

Yeah I wouldn't want to put spacers on my accessories at all. Running up to 7k would not be a good idea without accessories solidly bolted to the block.
So you were able to shave the balancer without any affect on crank vibrations?

anesthes

iTrader: (12)

Yeah, I don't know what the LT5 balancer looks like but a aftermarket SFI balancer typically has a face that can be milled off.



Another option, is you could cut 1/8" off the other side IF you have enough clearance between the seal and the end of the hub.



-- Joe

Dominic Sorresso

Interesting. Was just looking at ATI site, and looks like they can custom build a hub, and/or incorporate reluctor into hub. Reducing the thickness of the hub and sandwiching a reluctor would be the most cost effective I would think.
LT-5 Damper is 6.95" dia. at 4.5lbs.

anesthes

iTrader: (12)

The problem you are going to have is fabricating a mount for the sensor(s).

-- Joe

Dominic Sorresso

Well I imagine that's not a unique issue to the LT-5 in this type of conversion. From what I have seen the block has bolt holes available for use. We have some creative machinists in our group also. We've all had lots of DIY experience when it comes to the only DOHC V8 Chevy ever used in a Corvette.

anesthes

iTrader: (12)

For Northstar it isn't unique no, I'm not aware of any aftermarket sensor mounts for any application other than OE.

I'm sure it's possible. I wasn't willing to make a bracket, so I went with an off the shelf item for SBC.

-- Joe

Dominic Sorresso

When it comes to the LT-5, there's not anything that's "off the shelf". Well maybe spark plugs and injectors.
Thank goodness the cylinder heads flow.

Six_Shooter

iTrader: (2)

My pulleys are spaced out by 1/4" on my Franken60 (That I built 13-ish years ago and ran for a couple years year round, and that same reluctor wheel and spacer for the water pump pulley are being used on my LX9 in my Datsun.

I used the same wheel with a different sensor mount and mounted to the front of the pulley/balancer combo on my L28 in my Datsun.

I've never had a problem revving to 6000 on any of those engines.

The only issues I have had where the belt is concerned. n the Franke60 I spit the belt once (about a month after getting it together, replaced the belt and and never had a problem again, even with no changes made. Still not sure why it spit in the first place.

And the first design of mt alternator mount for the LX9 broke twice, even after re-inforcing it after the first break, so I built one out of steel instead of aluminum.

Moving the pulleys out by a 1/4" is not a concern, as long as the spacers do not have obvious out of balance issues. There are crank trigger kits such as those supplied by MSD for their ignition boxes that have spacers for this very purpose and you have to believe that many of the engine that these are being attached to will be revved very high and some for prolonged periods.

Franken60 during the build on the stand:


Datsun L28:


I don't seem to have any pictures uploaded of the set-up mounted on the LX9, but other than modifying the base of the sensor mount a little to clear the lower engine mount support and shortening the sensor mount itself it's the same set-up as used on the Franken60 above.

Dominic Sorresso

SS,

Good information. Thanks for the pics. Great information.

anesthes

iTrader: (12)

I looked a little more closely into your LT5 engine and I would go COP on this application. Even if you did wasted spark, I think the COP would be nice and clean.

It looks like you have a 58X crank trigger and a cam sensor. So why wouldn't the Northstar DIS module work as is?

-- Joe