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My Electronic Ignition for Onan 4 CCK

K D Redd

In Memory Of
If you all may remember I got a very unloved Vacu-Flow 4.0CCK-3RC sometime back. I got it running and converted to use LP as a second fuel. I have NOT loved it much better as it is setting under a well worn blue tarp in front of the shop as we speak. I mention that I would do MY TAKE of a electronic ignition system using relative commonly available/universal parts. I have the system finish though I have NOT ran the generator yet but I KNOW this system will work because I have used it on Tecumseh HH and VH cast iron engine with Tecumseh's early electronic magneto. There will be several picture so I will have to make several posts. Parts used are a Proximity Detector, a GM four pin HEI module and a GM coil from a Late Model Distributorless engine. A stock CCK coil can also be used. The flywheel will need some minor modification so you will need some fabrication skills.
I first looked for a place to mount the proximity detector under the flywheel shroud BUT I could NOT find a likely place. I decided to mount the detector in the shroud. I arbitrarily picked a spot about 3 inches to the right of the 1/4 inch shroud bolt the is in the cam/governor cover and measure the center so the center of the hole was over the center of the flywheel. I drilled a 3/16 check hole. I then put white paint from a White-Out pin to touch the flywheel to check location I was about 3/16 off so I drilled another hole to hit center. I enlarged this hole to 3/4 inch with a step drill. I tapped a heavy flat washer to 3/4 by 16 thread which I bolted into this hole. It was welded welded into the inside of the flywheel shroud. This is the thread on the proximity detector. I then marked two places centered in this hole on the flywheel. One at Top Dead Center. One at 22 degrees Before TDC. I modified a 3/4 inch by 16 thread bolt into a drilling fixture to drill a NUMBER 14 drill hole at TDC and 22 degress BTDC. You want these holes about 1/4 inch deep. Into each hole you will drive a about 1/2 inch long 3/16 inch dowel pin. I could not find/did not have 3/16 dowel pins so I used the strait shank protion of some number 10 allen bolts. The length of these two pins is not critical as long as the pin at the 22 degree mark is 1/16 th (.060 inch) shorter than the one at TDC.
I will stop now and add some pictures.

Kent
 

Attachments

K D Redd

In Memory Of
Re: My Electronic Ign. for/4 CCK

Continued from above: Next I mounted the proximity detector in the shroud. The detector picture I bought at a flea market at a engine show. I gave a buck a piece. I bought ten. The mistake I made is I did not buy all the vendor had because I found out that new these detectors are about $100.00 each from a source like Graingers. Thus it is the most expensive part of this conversion. It needs to be spaced about .010 inch from the long pin. You will have to estimate by using the thread pitch. Screw the detector until you bump the long pin. then back out a little less than 1/4 turn. The wires on the detector are terminated with a 1/4 inch female blade terminal on the Black wire and a 3/16 female blade terminal on the White wire. The Black wire will connect to the "W" terminal on the GM HEI module, the White wire will connect to the "G" terminal of the HEI module. The "B" terminal of the HEI module will connect to the 12 volt ignition feed and to one of the low tension terminals of the coil. If the low tension terminals of the coil are marked + and - you connect to the + terminal. The other/negative low tension terminal of the coil connects to the "C" terminal of the HEI module. the module MUST be mounted on some sort of a heat sink with heat sink compound and it MUST be well grounded. The HEI modules cost about $22.00 at a local parts store.
As I said earlier you can use the stock Onan CCK coil BUT I decided to also use a later GM coil from their Distributorless engines. I did modify the connection system on this coil. The original connector was for a factory connection rail. What I did was to drill and tap holes so I could use 10-32 screws to make the low tension connections. THIS MAY be a weak point in this conversion. The primary resistance of this coil is SO LOW that it is best used with a solid-state switch like a HEI module. This coil is about $25.00. Two 8 MM plug wires were also added for about $10.00.
I ask that the moderator look at this posting and IF he thinks it has value, Maybe it can also become a STICKY with any editing he may think is needed.
I will need to make one more post for one additional picture.

Kent
 

Attachments

bobbyz72

Registered
Re: My Electronic Ign. for/4 CCK

Isnt using OEM parts a lot easyer, being every thing fits easly once the front cover is replaced, and theres no timing or space issues to figure out.
 

Wayne 440

Registered
Re: My Electronic Ign. for/4 CCK

I like the "...commonly available/universal parts..." idea; OEM parts are fine until you need a replacement on Sunday morning.
 
T

trowel

Guest
Re: My Electronic Ign. for/4 CCK

sometimes, OEM parts are out of range, and there are no points to clean,
thanks KD REDD, this can be applied to other engines,
trowel
 

K D Redd

In Memory Of
Re: My Electronic Ign. for/4 CCK

I was given a 5 KW Kolher RV generator that was more unloved than the CCK, Locked-up from setting out in the weather. The owner gave it to me just in time. I freed it relatively easy. When I get it running, it will also get this treatment.

Kent
 

Jim McIntyre

Subscriber
Last Subscription Date
07/10/2019
Re: My Electronic Ign. for/4 CCK

...I mounted the proximity detector in the shroud. The detector picture I bought at a flea market at a engine show. I gave a buck a piece. I bought ten. The mistake I made is I did not buy all the vendor had because I found out that new these detectors are about $100.00 each.
...err... if this conversion needs a $100 sensor, why not just use Onan's OEM electronic ignition part, which needs no HEI module? I mean, great that you have a handful of $1 sensors, but what about the rest of the world?:shrug:
 

Kimbra Dean

Subscriber
Last Subscription Date
07/17/2019
Re: My Electronic Ign. for/4 CCK

Looks good to me but why do you need the second pin at TDC and why does it need to be longer?

I think you can get the same type of sensor in a smaller diameter which may be a little more convenient. The smaller diameters usually have a shorter sensing distance but would probally be OK.

I guess this means that you have high energy Ignition. Do you suppose there would be any benefit to increasing the spark plug gap?
 

K D Redd

In Memory Of
Re: My Electronic Ign. for/4 CCK

The reason for the two pins, I realized last night after I made this post I did not explain the two pins, is with the longer pin at TDC will trigger the ignition during starting. When the engine comes to speed, the shorter pin will then trigger the module, along with the longer pin but it's spark is wasted during running, automatically giving you a retarded timing for starting and advance ignition timing for running. THIS is a blatant copy of what Tecumseh used on their HH and VH model engines with their late 60's early 70's electronic magneto.
Someone commented about about the issue of figuring out the timing points. The is NO issue with this. Once you have the local fixed of the detector mount, you use the resident stock timing marks to mark the location of the pins. Set the stock timing marks at TDC and make a mark on the flywheel centered in the detector mount area for the TDC pin. Then set the stock timing marks at whatever advance you want to use. Then mark the flywheel for the location of the advance pin.
As to the cost of the proximity detector. Yes they are expensive new. I did not realize this when I bought the ones I have. If I had know I would have bought everyone the vendor had, BUT looking at the cost of the Onan parts that jwrape used in his electronic ignition MCCK,CCK Thread/Sticky, if you have to buy the proximity detector new the cost of my conversion is still cheaper. You might get lucky, as I did, to find the detector as a cheap surplus unit. My cost for this was $ 1.00 for the detector, $ 22.00 for the HEI chip, $ 10.00 for the plug wires, and $ 25.00 for the coil that I did not need to replace. That is a total $ 58.00. If I bought the detector new the cost would be $ 157.00. The cost of jwrape conversion was $ 256.00.
I do not want to debate what parts are used. If you want to use OEM Onan, that is your choice. I am trying to show what can be done with OTHER than OEM parts that may be more easily obtain and a "Little Knowledge ( which is sometimes a DANGROUS Thing)" of electrical systems.

Kent

---------- Post added at 08:53 AM ---------- Previous post was at 08:47 AM ----------

sometimes, OEM parts are out of range, and there are no points to clean,
thanks KD REDD, this can be applied to other engines,
trowel
Yes, this can be applied to other engines. I was going to use this system on a Briggs Model ZZ to drag it KICKING and SCREAMING into the 21ST Century BUT I was able to figure out how to install a Tecumseh magneto coil on to the Early Briggs magneto armature to retain magneto ignition.

Kent
 

markviiisvt4

Registered
Re: My Electronic Ign. for/4 CCK

Great little idea ya got there. Those wasted spark coils are everywhere. Couple questions.
What did you use to measure the 22 degree seperation.
What year range am I looking at for the 4 pin modual. 70s id guess.
Any wiring diagrams.
And last I have a couple CWs that use a fairbanks morse magneto. Is there any way to keep the magneto but bypas the points with a system like this?

Answered my own question about the pin locations.
I assume your using and inductive style sensor? If so there are many different ones that can be had off ebay for the 10 to 20 doller range.
 

K D Redd

In Memory Of
Re: My Electronic Ign. for/4 CCK

I do not know how to put a wiring diagram in this posting area but if you follow my wiring description you should have no problems. Again the pins on the four pin GM HEI module, any good parts store will not need any other description, are marked "W", "G", "B" and "C". The "W" and "G" terminals are the connection point for the proximity/magnetic pick-up. The original GM pick-ups used in HEI distributors had a Green and a White wire. If GM followed wiring color code conventions, the Green wire was the Ground side of the pick-up and the White wire was the Hot side. This is why I connected the White wire from my detector to the "G" terminal and the Black wire to the "W" terminal. In all reality, these two connections CAN be connected the other way without any difference in operation. I have tried both ways on the mix of a Chrysler Electronic ignition distributor and a four pin HEI chip I am using for the ignition system on a 1967 Dodge 400 Truck. Either way the pick=up is connected to the HEI module seams to work equally well with no timing change. The wiring of the "B" and "C" terminals on the module are a different matter. You must connect a Positive 12 volts to the "B" terminal. you also connect this 12 volts to the positive side, Low Tension terminal of the coil IF the coil is marked with a polarity. This voltage is also switched to stop the engine. NOTE: NO Ballast resister is used and you SHOULD NOT use a internal resistor coil. The module DOES NOT like this. I know from experience. The "C" terminal of the module is the terminal the does the switching of the system like a set of points would. It is connected to the other low tension terminal of the coil. The negative terminal if it is marked. The HEI Module needs to be well grounded and mounted on some sort of heat sink using heat sink compound. One might also wish to use a dielectric grease on the four terminals of the module.

Kent
 

K D Redd

In Memory Of
Re: My Electronic Ign. for/4 CCK

I was just looking at the sensors on Ebay. Most are of the active three wire type that use a transistor for switching. The sensor for uses with the HEI module needs to be a two wire type that outputs a AC signal when the metal pin passes near the sensor.

Kent
 

B.Ikard

Registered
Re: My Electronic Ign. for/4 CCK

A well thought out effective, resonably simple and cheap mod!

On the prox. sensor-what kind of VAC do you develop cranking/running?

I have several magnetic pickups that look similar that are to adjusted to 1 VAC during cranking to feed an electronic gov control engine speed data.

No longer have these units (MEP 806A) and these parts will never be used.


Brent
 

K D Redd

In Memory Of
Re: My Electronic Ign. for/4 CCK

I have NOT looked at the output of these mag. pick-ups with my scope. I have only tested them with a analog VOM on the meter's lowest AC scale. When you wavy a piece of steel across the pick-up face the meter needle will show a electrical signal is produced. The HEI Module may be somewhat forgiving of the input from the pick-up. It likely, BUT I DOT NOT know, has some clamping on the magnetic input side.

Kent

Brent,

That may be where these pick-up I am using may have come from. What does the connector on the mag pick-up look like? I guess I could take a picture of the connector on the pick-up I have still not modified and post the picture.

Kent
 

K D Redd

In Memory Of
Re: My Electronic Ign. for/4 CCK

I started my 4.0 CCK with my electronic ignition mod. today. Other than a fouled plug, she ran OK. I have this generator plus the Kohler that was given to me locked-up mounted on old riding lawn mower frame with modified 55 gallon barrels for enclosures. It may not look pretty but they are both more in the dry than they were and they are a lot easier to move.

Kent
 

Flintstone

Registered
Re: My Electronic Ign. for/4 CCK

Neat Kent. Love to see home-spun engineering working. Thanks. Now the test if time eh? At the bottom of my hill sits a little Brigs hooked to a car alt, with 1/2 a drum over it. Ben there a long time waiting with 12v for the last car that wouldn't role/push start. The brigs has points though! D.
 

K D Redd

In Memory Of
Re: My Electronic Ign. for/4 CCK

I am bumping this topic of mine back to the top because I may have found a cheaper alternative to the Mag. Pick-up/Proximity detector I used. The one I used, I found in a Flea Market at a engine show for a dollar. I later found their new cost was around $100.00.
The cheaper alternative is Borg-Warner P/N CSS81. This is the cam position sensor fro Late 90's/early 2000's Ford diesels. This sensor cost $19.00 plus tax. The down side is it takes a special plug, BW P/N PT5742 that cost $21.00 plus tax.
I only found this detector last week, picked it up last night so I have not had a chance to test if it will drive the GM HEI Module. I would do the testing today but I have three Doctors appointments to take Dad to today. These are standard follow-up so nothing to get excited about as far as I know this morning.
I will do some testing and be back with the results.

Kent
 

Ed Stoller

Subscriber
Age
79
Last Subscription Date
07/11/2019
Re: My Electronic Ign. for/4 CCK

For the Tecumseh SSI replacement, the spark timing is off the tall, TDC pin for starting and automatically switches to the short pin, advanced as the RPM increases. This happens because the small air gap with the tall pin produces a higher voltage and the voltage from the short pin is initially too low to trigger a apark. When I make the trigger coils, I adjust the number of turns of wire so this transition occures between 550 and 650 RPM for the Chrysler Control Module or Wells CR 109. I picked this point as it is just above the capability of the starter motor so it won't kick back. If someone wants to try this on an Onan Twin, I woud be glad to provide the trigger coil.
 
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