Coil on Plug Conversion

[Matt Cramer]

More dwell time. Depending on the setup, each coil only fires once every two revolutions or once every revolution. With a distributor, the coil fires three times in a revolution, and dwell has to drop off at high RPM.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

[KitCarlsonEMS]

1. Eliminate the spark plug wires, rotors and distributor cap.
2. Higher rpm potential.
3. Increased efficiency, with proper dwell control.

[Rug_Trucker]

[SurfRodder]

I'm planning on doing this once I finish collecting the parts. I am going to use an EDIS module/VR sensor and associated wiring from a junker with a trigger wheel from DIYautotune which will input to either a MegaSquirt(ability to go EFI in the future, if I can ever talk my sister into it...its her car and the only slant I work with) or a Megajolt(only IGN) box to tie it all together and tell the coils when to fire.

My main reason for doing this is far better spark control and fewer fluctuations by eliminating the distributor. I'd much rather set this up and plug my laptop into the car to adjust the advance (to whatever I feel like trying) in about a minute, vice taking the dizzy off the car and swapping springs which will be at best a decent compromise (less tune-ability) and a much bigger PITA for fine tuning. The car is already setup with GM HEI and I will likely leave that and the dizzy installed to have a backup just in case, at least until I feel confident that the system is totally reliable as some of my parts have been collected from junk cars.

This is a far more capable system and not extremely complicated...I think some people may be intimidated because it's electrical and they have let the magic blue smoke outta the wires too many times in the past...I dunno.

I am interested in going straight to COP, vice just using the three coil setup from regular EDIS, because while it is going to be more expensive to setup initially, I think it will be a lot mroe fun to do, potentially have the ability to keep running if a coil fails(although having more coils increases the likelihood that one will) and it will look pretty cool too. I look forward to being able to fine tune the advance curves to maximize the performance of the engine.

Anyway, eliminating the distributor is reason enough for me to do it. YMMV.

[GunPilot]

[75duster]

why not use like the gm ls engines and have coil near plug?

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1975 Plymouth Duster,225/6 2bbl. and duels, 904, 7 1/4
1986 Dodge Charger Shelby, 2.2 Turbo I, A525

[Pierre]

Wow, sorry... I haven't been around the board much... let me see if I can find any of my old threads.

Here it is. I've changed some things around though. The module is mounted on the inner fender. The coil is mounted in the stock coil location - I also switched to a dodge coil - it has male posts instead of female ones and a flat bottom so it makes mounting easier. Also makes sparkplug wire routing a lot cleaner. What else.... oh, I put a serpentine pulley on the front of the damper so I had to space everything forward.

I'll take new pix if you want. Haven't done any more thinking on COP... its a daily driver so I don't have much room for experimenting.

[Sam Powell]

It seems to me stability in timing is the big plus, which should result in more stable idle. It gets rid of the timing chain slop, and the fact that inertial advance is often on the verge of coming in just above idle resulting in few degrees of bounce there.

Sam

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A REAL professional is someone who knows when to hit it with a bigger hammer.

[Pierre]

Yup.. if the sensor is mounted securely, it is rock-stable. There are two wires connecting the MS to the EDIS module. If you sever one it goes into a default "limp home" mode of 10deg advance. I believe ford did this intentionally to allow you to set sensor position or as a diagnostic feature. I use it to set my sensor position just right. With the engine running I can change the sensor position and watch the timing mark to get it where its supposed to be. There is a jumper like connector on this wire on the stock ford harness that allows you to easily unplug it to cut the signal. Anyway... with this jumper out I can rev my setup and the timing mark won't budge a hair. If it does something is loose.

[MJF]

So has anyone found a COP that fits nicely in spark plug tube? I was also thinking Chevy LS CNP, but COP would look nicer without wires

[Sam Powell]

It seems to me maybe this needs an article kind of like the one Bob DeBiase (sorry about the spelling) wrote for the initial GM EFI to slant swap.

Sam

PS. Somebody may certainly correct my spelling of Bob's name if it's wrong.

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A REAL professional is someone who knows when to hit it with a bigger hammer.

[olafla]

Before taking the final desicion regarding what system to go for, take a look at the links below. There are some interesting products emerging because of the environmental issues, that might be very useful for 'ordinary' engines like ours, and that may be incorporated in a solution with coil-on-plugs. Take a look at some of these products; multi discharge coil-on-plug, or using the spark plugs as knock-sensors by sensing ionized current, all integrated into a coil-on-plug. The principles are old, see this NACA report from 1940(!). Todays micro electronics and miniature sensors makes it possible.
Here are some examples from delphi.com.

Hmm....

Olaf.

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Aspenized

[Sam Powell]

I looked over the links and this seems to be wonderful stuff that you would really have to know what the heck you were doing to make use of. Somebody who had mastered the Megasquirt might be prepared to run with something like this. At least that is the way it seems to me.

It looks like pro grade all the way. But then web sites can look good despite the actual content.

Sam

_________________
A REAL professional is someone who knows when to hit it with a bigger hammer.

[SurfRodder]

Here's What I ended up doing:

http://i45.photobucket.com/albums/f100/SurfRodder/EDIS4.jpg
http://i45.photobucket.com/albums/f100/SurfRodder/EDISSensorMountSlant6.jpg
http://i45.photobucket.com/albums/f100/SurfRodder/EDISsetup3.jpg

currently being pushed by a coilpack form a 1996 Voyager V6:
http://s45.photobucket.com/albums/f100/SurfRodder/?action=view&current=EDISVid.mp4

This is my ultimate goal though, once I have the time...I messed up the wiring on this setup, have them wired up incorrectly...sucks because I spent a while getting that done....just gives me an excuse to do a true COP setup:
Ford CNP:
http://i45.photobucket.com/albums/f100/SurfRodder/COP2.jpg
http://i45.photobucket.com/albums/f100/SurfRodder/COP1.jpg

[Pierre]

How are you going to secure the COP coils to the head? Or do they just float on the plugs?

Edit: What's the stock application for those coils?