Ignition upgrade to full coil system

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Zuluman

Zuluman

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I'm curious to know if anyone has done an ignition upgrade to a modern, full-coil programmable system, perhaps from a Mopar engine of similar capacity as a slant-6 ?

The engine of my car is highly modified and I still get pre-ignition (detonation, pinking) even with 100 octane (Shell V-Power, even 102 from Aral when I'm in Germany).

All suggestions and advice would be highly welcomed.
 
start by going to colder heat range plugs. and / or one with the center electrode is retracted flush with the base.
 
I don't know what "full coil programmable" means. You can find much info on the megasquirt site and their mega-jolt box is a spark-only controller (one option). Simplest is to use an electronic distributor (Mopar factory is fine) to drive a GM 8-pin HEI module and GM external coil. Several engine controllers can adjust spark via the 8-pin module. You can find Holley Commander 950 controllers for a reasonable price on ebay. I bought one ECU-only for $150 on ebay. It works best with a knock sensor (take sensor & module from same GM above, 85-95 V-8 truck or 85-93 car). There was a simpler spark-only 8-pin controller termed "Rabid Gator", which you can find a manual on-line, but it never went into production. The simplest distributor-less system to mod is the Ford EDIS, described fully on the megasquirt site. Adding a crank trigger wheel is tough, but a youtube video shows one on a slant.
 
Going to Megasquirt seems a bit overkill to just cure some pre-ignition.
In the end, the engine will run better, but if you can't fix the detonation with the simple stock ignition system, you won't be able to cure it with the much more complex system of a Megasquirt.

That said, you could look into a simple programmable ign. timing with vacuum input like to the 'BlackBox' from CB Performance ignition;
http://www.cbperformance.com/ProductDetails.asp?ProductCode=2013

I've recently bought it myself to have some easier control over ignition timing, instead of having to completely disassemble the stock distributor everytime I want to make a simple change in the curve fi.


What all has been changed and modified on your engine anyway?
 
I am wondering where/how you would hang the coil paks from on the side of the /6 head; I guess you could build in a support rail.
 
BigBlockMopar, thanks for the link. First I heard of the BlackBox, and affordable at $200. It adjusts spark based on rpm and manifold vacuum, similar to a distributor but easier and more flexible adjustments. The only thing it misses is a knock input. Most modern spark controllers keep advancing timing until they sense knock, then back off a few degrees and repeat. That gives best performance & mileage and compensates for whatever gas you get and temperature.

Re coil choices, distributor-less ignitions use multiple coils. Coil packs (ex. Ford EDIS) usually have 2 cylinders share one coil in the "wasted spark" method. Slightly better is an individual coil per cylinder, either "coil on plug" or "coil near plug". Megasquirters like the later, in GM LS coils since they have in integral drive "ignitor" so just need a 5 V signal to control firing. I have thought of doing that in my slant engine, with a slick-looking aluminum mount down the inner fender.
 
For your helpful and thoughtful replies. I will study and test the suggestions and revert with the results.

Apologies for my poor English - it's not my mother tongue and differences in technical terminology in UK and American English can confuse me sometimes.
 
BillGrissom said:
BigBlockMopar, thanks for the link. First I heard of the BlackBox, and affordable at $200. It adjusts spark based on rpm and manifold vacuum, similar to a distributor but easier and more flexible adjustments. The only thing it misses is a knock input. Most modern spark controllers keep advancing timing until they sense knock, then back off a few degrees and repeat. That gives best performance & mileage and compensates for whatever gas you get and temperature.

Re coil choices, distributor-less ignitions use multiple coils. Coil packs (ex. Ford EDIS) usually have 2 cylinders share one coil in the "wasted spark" method. Slightly better is an individual coil per cylinder, either "coil on plug" or "coil near plug". Megasquirters like the later, in GM LS coils since they have in integral drive "ignitor" so just need a 5 V signal to control firing. I have thought of doing that in my slant engine, with a slick-looking aluminum mount down the inner fender.
Click to expand...

I was looking at this controller the other day and noticed that.
Seems to me that would be pretty important if it can control timing for boost via the MAP sensor, let alone under normal conditions on a NA engine.
Wonder why they didn't just go ahead a take that last step.
 
BigBlockMopar said:
Do you really want a $3000+ ignition system?
Click to expand...

Frankly, yes. My overall approach comes, in part, from need ; I don't have access to a lot of the resources that are available to the average builder in America. There are breaker's yards in Europe, but very little American metal from which to scavenge parts I read about in this forum.

So, I've chosen a different path ; start with what I have and pick and choose from after-market catalogues to build something unique. My (evolutionary) approach is to build a more modern drive train from a slant-6 base. This also ensures that I'll have reasonable access to most replacement parts for the next 10-20 years.

Perhaps I was a mad Mopar engineer in another life and am determined to demonstrate the merits of the slant-6 (and my own engineering skills) to a world that is underwhelmed by this engine ? My respectful apologies to any originalists reading this. For me, this is an interesting exercise and, thankfully, I have the means to indulge this whim.

That said ; do you have an opinion on what I seek to do ?
 
Did you check the MegaJolt box I mentioned? There is much info about ignitions on the megasquirt site. I don't think the $3K system above would give any better spark than a distributorless system like the Ford EDIS or the (better) GM LS truck coils. Both are popular w/ megasquirters. There is a youtube videos by a megasquirt originator showing the spark from an LS coil. I wouldn't want to touch it.
 
Dear Bill, the only concern that I had about the MegaJolt system you recommend is that it does not have an engine knock sensor. I'm less concerned about the spark than I am about the ignition curve, in order to avoid detonation.

But I see another virtue in your suggestion ; if it works then it's a much cheaper solution than the one I've found. It merits a test. I shall do so.
 
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