When I first started it up I had no spark. Turns out I had reversed the
connections for the trailing coils on the trailing HEI module. Now I have
trailing firing and it runs as good as any rotary that is running only on
trailing.

I still have no spark to leading but thats either a wiring issue or
both coils are bad. Another evening with the DVM and a charged battery
should reveal the problem.

I would have had this done but Easter got in the way Damn holidays!

 

Congrats on getting trailing to work on your DLIDFIS clone. lol

 

K now work out the kinks and sell it as a kit with install instructions that have pics for igntion stupid people like me

 

Basically, but with easier to source and cheaper, stronger components (I think).

DLIDFIS was a big step forward. I'm just standing on your shoulders and
taking it to another level with different components.

 

I don't think thats possible. To make a kit I mean

 

How much did all the parts cost? Is it significantly better than the 2g leading conversion? If so in about 6-12 months if I come up with some money could you come up with all the parts I need and some detailed instructions and ship it all to me?

 

Sure for $10,000.00, no problem.


























Ok, I'm just messin with ya. I'm not in this as a business. This is one of my hobbies.
I spent 20 dollars at pullapart for the 2 TFI coils and the 4 HEI modules. Although
the HEIs may have been missed in the inventory, if you know what I mean. I spent
another 17 dollars for some aluminium stock which I used about 1/4 of and I spent
another 17 dollars on misc stuff to do the wiring and loom. I did spend about 50 bucks
on a new spark plug wire set. I probably could have cobbled the old RB one into
working but I wanted a clean install. All in all less than $100.00 in materials and
my time to design the circuits (trivial) and put it all together (not too hard).

 

Holy crap! Nvrmnd I'll stick with my 2g leading coil.

 

Alright, this mod rocks as far as I'm concerned. I just did a test
drive on my favorite loop and it felt as good or better than the
old J105 and 2G coil except it isn't failing when it gets hot

The leading spark issue was a combination of poor + connections for
the HEI and TFI coils, poor grounds on the HEI modules and fouled
sparks plugs. I pulled the harness I made and ohm it out to make
sure its was good then I reconnected it all. I have the positive HEI
and coil wires on 2 loop connectors that attach at the trailing
coil. These were not seating flush with each other and it
was causing weak to no spark. Of course my timing light
fritz out on me as I was working on it so I'll have to fix that
as some point.

I have the grounds for the HEI modules in the wiring diagram but
I omitted them when I first wired it up thinking the modules would
ground thru the aluminium plate they mount on and to the shock
tower. So I added those grounds as well. This seemed to help a
whole lot. Remember always follow your design, don't change
it in the middle of implementation. Always bites you in the a$$
every time.

I then deflooded and dried out the plugs. Put em in and fire it
up. Ran good. I let it get good and warm while I monitored
the ignition. I disconnected various leads causing one coil
at a time to be disabled to make sure I was getting good
spark all around. Doing this didn't kill the engine but it
did idle kind of rough as I disabled each leading coil.

One issue I had/have is that plugging the tach lead into the
trailing coil negative produced a really poor signal for the tach and
made it read very erratically. The trailing seemed to be working
fine, as it would run with both leading coils disabled. So I jumpered
it over to the C connector of the L1 HEI module and its works like a charm.
I'll have to look into this further but its probably a grounding issue
on the trailing HEI module I suspect.

Next I'm going to take the harness I made off and solder every connector.
I used the blue and yellow crimp connectors and I think soldering them
will make this a more stable implementation.

Longer term I can now purchase HP HEI modules and TFI coils from vendors
like Pertronix, Mallory etc. I'm not sure its worth doing but at some point
when I have some extra cash I may do it just to see if theres a difference.

 

Glad to hear it came out as you wanted! I was curious how the different style ignition modules would work out. Do they get as hot as the J-105's or 109's? Sounds like a nice mod. I had a similar issue with the tach when I used the GM hei modules, turned out they will work with the polarity either way, but they work better with the polarity reversed. As soon as I did that the tach signal was great.

 

They barely get warm, and thats after some spirited runs. I expect they should
last awhile. I have a spare just in case.

 

More news. The good is that this ignition is much stronger than the
J105/2G coil solution. It cold starts immediately and hot starts are
very good as well. It's comparable to the increase in ignition quality I
experienced going from the stock to 2G coil solution. Its very
noticeable.

From idl to 4500 rpm its very strong and helps cure some of the
stumble I get from the Dell. Very good initial acceleration and it
really sounds different, more raspy and bit louder.

The bad is at 5K and above it's breaking up a bit, enough that I get
backfires under load. Not a desirable trait at all. I'm not sure if this
is due to my implementation (bad wiring, cross talk etc) or due
to the GM OEM HEI modules I'm using. I know there are rumors
that these things have problems with high rpm applications. I also
have read about them having a built in advance of 10 degrees
but I think thats not really true. From what I've read the dizzy in
the GM applications is installed with 10 degrees advance and thats
what used if the HEI doesn't get a tach override signal on its input.
Since my timing light broke I can't really verify what timing it's
running at right now. Have to get that fixed.

If anyone using the 4 pin HEI modules on a rotary could comment
that would be great. Do you experience breakup above 5 or 6K?
Would after market modules work better?

 

I was using the 4 prong "high output" HEI's on the red 7, and it had the same issue. Try swapping the polarity on the igniters and try again. That cured mine. Found out later that they will run either way, but at higher rpms, the advance is wrong if you have it one way, wish I couls explain it in more detail, but I honestly can't recall the reasoning, just that it worked.

 

I did try reversing the polarity but it hardly runs at all then. I need to get
my timing light on it and see whats its doing. These aren't "high ouput' just
run of the mill GM OEM from the junkyard so I'm not too surprised.

 

Yeah, a timing light would be a big help at this point. I do remember reading something about the timing curve change on the hei modules and the need to change the trailing timing. I'll try to find it again. Most of what I've read or done only applies to the 4 prong HEIs though, I'm not familiar with the ones your using. Jeff20B would be the best shot at an answer to this. You'll still need the timing light though.

 

Went to a meet yesterday and got out on the interstate and was able to wind it out.
It appears to rev up thru 7K with no problems 80% of the time. At times it
hesitates around 5K and either backfires or knocks a bit. I'm thinking I need to
reset my timing. I use manifold vacuum on the advance and of course theres the
mechanical advance as well. By 5k the dizzy should already be fully advanced so
the only thing I can think is adjusting the base timing of the dizzy. It could also
just be interference of some kind.

The good news is when its working good its great. This mod is even better than
the 2G coil mod, hands down. I suspect the only better one after this is to go
with an MSD. I would love to put this on a dyno and see if it has added some
ponies. It sure feels stronger, especially low down.

First thing I'll do is solder all my connections in the new ignition harness I made.
Then I'll fix that timing light and see whats up.

This has been a fun project for me. I'll keep posting here until its 100% working.

 

Wouldn't hurt to double check the timing I would have been there yesterday but
been busy with the car as usual. I know you might know this already, but I set the
timing to Paul Yaws timing on his page.

I love the MSD box, the only thing I don't like is it needs more than 10v to operate.

 

I've got my timing set to 19 and 2 as speced by RB when I first got the Dell.

I think now that I have the electric fan, Carter pump and now the 3 HEI modules
I'll need to get a bigger alternator. I'm still running the original (rebuilt) stock SA
alternator and I'm pretty sure its barely adequate.

 

Get you a nice S4 alternator Mine bolted right up. Semi-noticeable difference, but
I came from a FB alt, which I believe has a few more amps.

 

Good deal Tim. You kept up pretty well for a "stocker" If you want a S4 alt, or even a 50 amp S3 alt, I can hook you up. Just let me know.

 

So I got my timing light fixed and checked out timing. Two things
showed up.

1. The trailing is only working at higher revs. Not sure if its because the
trailing plugs are fouled or what. I disconnected trailing to do further
testing so it doesn't get in the way.

2. The timing was right where it should be 2 degrees BTDC per my
Dell RB. Thats where its lived since forever. I did notice after about 4K
the timing light seemed to show it advancing pretty far. Right at 4K
it was at about 22 which is where it would be expected. After that it
seemed to jump way past there.

So I'm thinking the setup is crossfiring or randomly firing for some
reason. Its not constant and seems worse sometimes that others.
Cruises fine below 4 or 5K.

 

well i the mod, But ran into a problem. Im using the 7 pin HEI modules on leading and a 5 pin on trailing. With trailing connected she backfires like crazy above 3k rpm. Im gonna troublshoot this some more. But idk how to connect the 5 pin modules so that could be the problem. Ill post up some pics later.

 

I'm beginning to think the 7 pin HEI modules mess with the timing in
some way. The 7 pin is a more complex device than the 4 pin and I
suspect that the 7 pin is adding some advance at high rpm or something.

Everything I've read so far talks about locking the dizzy when using these
but thats due to the ECU being connected to the extra 3 pins which
control the timing. My assumption was that without the ECU connected
the timing would be unchanged and the module would just trigger the
coils based on the reluctor signal. This seems to be the case up to about
4500 rpm but then it goes crazy for a bit and after that it continues to
spit and pop up to 8000 rpm. Probably not good for my motor.

I think I may go buy some 4 pin HEI modules to see if that fixes it. If it
does then great, I've learned something. This could be why all the
mods for ignitions that use the HEI in non-computer controlled systems
use the 4 pin. I do know the 7 pin works if your using a MegaSquirt. In
fact on the MS web site they show how to wire up the 7 pin to work.

I've decided I'm going to remove the trailing all together, since it really
doesn't contribute much and it will make things a bit neater under the
hood.

 

Do what I did and disconnect the trailing while your debugging, it makes it
easier to work through any issues.

Also you can disconnect the leading and the engine should run just on the
trailing if you need to debug that as well. When I originally did this mod only
the trailing was working at first but it would start and run, just a bit rough
and weak

 

I got it all good to go. The 7 pin works just fine. Revved to 8 and beyond. My trailing was all messed up. But all bugs are worked out and she runs amazing