# Electronic ignition vs. Old style points and coil



## Brian Rupnow (Aug 1, 2013)

I am about to take a step in a direction I have never gone before. I have built 4 previous i.c. engines, and have used an automotive 12 volt coil, points, condenser, and 12 volt battery. They all run well, but I want something with a hotter, more reliable spark for my most recent engine. I have just ordered a complete electronic ignition kit from S & S Engineering. I would appreciate thoughts from people who have built and ran model engines successfully using both the old style coil and points as well as engines using the more current electronic ignitions. I wonder--Do you get a hotter, more reliable spark with an electronic ignition, and are they difficult to set up. Any insight would be much appreciated.---Brian Rupnow


----------



## stevehuckss396 (Aug 1, 2013)

Yes you get a hotter spark with the CDI ignition. I have seen the spark jump about 1/2 inch looking for somewhere to go.

They are no harder to setup than any other ignition. A few things to watch out for.

The sensor only operates on one pole of the magnet. I usually setup the ignition on the bench and "test" the magnets to find which side fires the ignition. Mark the magnet with a sharpie and then you can get it installed in the correct orientation.

Take a heavy ground wire (#16 or #14) right off the negative side of the coil to the head or engine block. The best way to protect the sensor is to have a good ground path for the high voltage.

Remember the spark happens when the sensor loses the magnet and the coil de-energizes the same as points.

The operating voltage of the ignition will be 3.3 - 6.0 volts. If all your engines run on 12 volt just wire a LM7805 in series with the power lead and bolt it on a heat sink. I power all my engines from 12v battery. Oldest is going on 4 years with zero problems.

Thats all i can think of at the moment but ask away and i'll try to help but I think you will find it to be very easy.


----------



## Brian Rupnow (Aug 1, 2013)

Thanks Steve---I appreciate the advice.---Brian


----------



## stevehuckss396 (Aug 1, 2013)

The first pic is the 5 volt regulator. The cap is something I do for all power supplies in the event I feed from rectified AC instead of the battery. You can probably delete it.

The second pic is the CDI board with coil. Left top of the coil is the heavy guage wire going to the engine block. Right top is the high voltage wire going to the distributor.


----------



## Swifty (Aug 1, 2013)

Will be following along Brian, my knowledge of electronics is just about zero, never managed to understand it.

Paul.


----------



## canadianhorsepower (Aug 1, 2013)

[QUOTE The sensor only operates on one pole of the magnet. I usually setup the ignition on the bench and "test" the magnets to find which side fires the ignition. Mark the magnet with a sharpie and then you can get it installed in the correct orientation.][/QUOTE]

It is usually the SOUTH that will turn it on, but Steve suggestion is foul proof
if some of you are interested I have some that will work detecting metal and not a magnet, if your planning to use a plastic part for disc a small screw will activate it.

[quote The cap is something I do for all power supplies in the event I feed from rectified AC instead of the battery. You can probably delete it.
][/quote]

Steve is right when he says you can probably delete it, but it's a dam good insurance to have


----------



## ozzie46 (Aug 1, 2013)

Don't want hijack the thread but I have been on Digikey site ordering parts fpr a ignition system and have all the parts in the "shopping cart' except the Hall effect sensor. I can't figure out which one to order. I have no electrical background or knowledge and the sensor page looks like a puzzle to me.

  Can someone tell me which one to order?   

Plan on using 12 volt Batt.   

 Thanks Ron


----------



## stevehuckss396 (Aug 1, 2013)

ozzie46 said:


> Don't want hijack the thread but I have been on Digikey site ordering parts fpr a ignition system and have all the parts in the "shopping cart' except the Hall effect sensor. I can't figure out which one to order. I have no electrical background or knowledge and the sensor page looks like a puzzle to me.
> 
> Can someone tell me which one to order?
> 
> ...



In the past I have used the Honeywell SS443.


----------



## stevehuckss396 (Aug 1, 2013)

stevehuckss396 said:


> In the past I have used the Honeywell SS443.




Sorry that would be a SS443A


----------



## canadianhorsepower (Aug 1, 2013)

ozzie46,
              cant give you any accurate p# not knowing what you are using
as a circuit. a very good guide line respect the voltage value, and a resistor for the current limiter and your in business:hDe:

someone can give you a story twice the size of a dictionary only to look good
:hDe:


----------



## ozzie46 (Aug 1, 2013)

Thanks Steve. found it at Digikey. Placing order now.

  Ron


----------



## canadianhorsepower (Aug 1, 2013)

stevehuckss396 said:


> Sorry that would be a SS443A


 
Steve -- SS443A are surface mount is that what you are using


----------



## canadianhorsepower (Aug 1, 2013)

if this is what your using no need for the  7805 check the specs


----------



## ozzie46 (Aug 1, 2013)

Thanks Luc. Placed the order be for I read your post. But I guess if it works for Steve it should work for me. Will be using 12v batt 

  I'm using this circuit, Post # 63,

http://www.homemodelenginemachinist.com/f31/new-ignition-circuit-20415/index4.html

   Ron


----------



## gus (Aug 2, 2013)

I thought the Antique HT Ignition Coil went kaput and I ordered from S&S the CDI which looked similar to O.S.
On further checks,HT Coil was OK,it was the contact point gap somehow grew from 20 thou to 40 thou and so no sparks.
Now I will have both Antique HT Coil with breaker contact point and a CDI in hand. Might try out CDI on the Webster.Will report results.
The HT Coil and Battery Pack looks like they just dropped in from Jurassic Park.


----------



## Rustkolector (Aug 3, 2013)

Brian,
I have 5 of the S/S CDI ignitions in single cylinder, multi cylinder distributor, wasted spark, and buzz coil applications. All have worked very well. I use 4 AA batteries on all of them. Battery life is great if you like to run your engines a lot. Don't be afraid to experiment with plug gap. I have one engine that responded well to  .040". 

Jeff


----------



## stevehuckss396 (Aug 4, 2013)

canadianhorsepower said:


> Steve -- SS443A are surface mount is that what you are using



Shouldn't be. The ones I have are 3 lead.


----------



## canadianhorsepower (Aug 4, 2013)

stevehuckss396 said:


> Shouldn't be. The ones I have are 3 lead.


Hi Steve 
It might be safer to order ss443, if you look at the data sheet on post 13 it says surface mount but I check other company and they are like yours:wall:
different company different name
one day they will all be OBD11 like cars

cheers

Luc


----------



## stevehuckss396 (Aug 4, 2013)

Well he ordered from Digi-key. The SS443A on there site is listed for a radial lead so the chance he go the correct one is high. 

TO-226-3, TO-92-3 Short Body, Radial lead.

That's the one I would pick. If you get the wrong one don't feel bad. Based on what i read at Digi-key's site, I would have ordered the same thing. You should be fine.

BTW!  Hey CHP!  Are you going to build one of these circuits for the Rupnow engine or are you going with the CDI from S/S?


----------



## stevehuckss396 (Aug 4, 2013)

Here is the page, see what you think.

http://www.digikey.com/product-detail/en/SS443A/480-2002-ND/701357


----------



## canadianhorsepower (Aug 4, 2013)

stevehuckss396 said:


> BTW!  Hey CHP!  Are you going to build one of these circuits for the Rupnow engine or are you going with the CDI from S/S?


 
Steve, I'll build the circuit. It's already on the bread board only 
have to do the PCB board for it.
It works very well,


----------



## gus (Aug 4, 2013)

Hi Jeff,Steve & Luc.

At 70 Gus is entering Jurassic Era. After misleading myself on the performance of the antique H.T. Ignition Coil and Contact Points,I went ahead fearfully to try out space age CDI. Gathered enough courage to read and understand CDI.
By the time I come home from Thailand,the CDI would have arrive by Speed Post.

Thanks for the kind advice. Will report Webbie's performance with CDI transplant.


----------



## canadianhorsepower (Aug 4, 2013)

gus said:


> Hi Jeff,Steve & Luc.
> 
> At 70 Gus is entering Jurassic Era. After misleading myself on the performance of the antique H.T. Ignition Coil and Contact Points,I went ahead fearfully to try out space age CDI. Gathered enough courage to read and understand CDI.
> By the time I come home from Thailand,the CDI would have arrive by Speed Post.
> ...


 
Hey Gus, I really enjoy your post and spirit. All you have to be carefull with is the polarity , the rest works all by itself
good luck


----------



## Art K (Aug 4, 2013)

Hi Brian,
On my engine I am using S/S CDI ignition and mid 70'S Datsun Points. The points are the trigger like the sensor and magnet. If I have the carb set right it runs at 6500-7000 RPM. When I had trouble with it I talked with Roy and he helped me sort out my problems, that being the engine grounds. it now works like a charm.
Art


----------



## Philipintexas (Aug 5, 2013)

I've built a number of IC Hit-n-miss engines and the most successful ignition I've come across is to use a 12V motorcycle coil (small size) and an automotive relay that rapidly cycles the coil on/off as long as it is energized. For a slow running engine it gives multiple 1/2" HOT sparks as long as there is a closed circuit.  It gives the same effect as an old buzz coil and will rock your world if you connect with it.


----------



## Brian Rupnow (Aug 5, 2013)

Philipintexas said:


> I've built a number of IC Hit-n-miss engines and the most successful ignition I've come across is to use a 12V motorcycle coil (small size) and an automotive relay that rapidly cycles the coil on/off as long as it is energized. For a slow running engine it gives multiple 1/2" HOT sparks as long as there is a closed circuit.  It gives the same effect as an old buzz coil and will rock your world if you connect with it.


Philip--That sounds like a very good solution. Do you use a conventional set of points to open and close the circuit to the relay? If so, you must have to engineer some "dwell" into the ignition cam.---Brian


----------



## gus (Aug 5, 2013)

canadianhorsepower said:


> Hey Gus, I really enjoy your post and spirit. All you have to be carefull with is the polarity , the rest works all by itself
> good luck




Hi Luc,

Thanks for the great advice. Electronic items are polarity sensitive. Get wrong
and my US$$$$$ goes poooooffff.


Now in Samui Island off the mainland of Thailand. The Weekender Resort has its own backyard beach with topless sunbathing but I have not been there yet. The island is quite remote from the mainland and the local police is blind-eyed.


----------



## Philipintexas (Aug 6, 2013)

Brian Rupnow said:


> Philip--That sounds like a very good solution. Do you use a conventional set of points to open and close the circuit to the relay? If so, you must have to engineer some "dwell" into the ignition cam.---Brian



Actually the opposite is true. I had problems with one single-cylinder engine, the "Points" were a metal plug sticking out of an insulated disk making contact to ground every other revolution of the flywheel. They revolved so slow the coil would not spark. A quick connect/disconnect would produce a spark but normal speed would not. With this method you get hot multiple sparks as long as there is contact. Translates into hundreds of chances for ignition. At 12V and multiple sparks I don't think the relay will live too many years, but at around $5 it's easy to replace.

If you Google "BOZZCOIL" you can get everything you need. It's not my idea, but I'm sure a believer.


----------



## canadianhorsepower (Aug 6, 2013)

Philipintexas said:


> you can use an electronic relay to do this job same specs guaranteed
> 1000000000 pulse


----------



## Brian Rupnow (Aug 14, 2013)

Okay--The verdict is in. I like the electronic ignition. The spark is constant and dependable, and it seems that as long as one follows the manufacturers instructions they are not as fragile as I had feared. The $105 was a bit hard to swallow, but that price included the battery pack and charger. If I build another engine, it will be cheaper ($85.00)  because I won't have to buy the battery pack and charger again. I'm absolutely sure that if I were to purchase components and wire up my own electronic ignition from components it would be cheaper still, but I really don't want to do that.---Brian


----------



## gus (Aug 15, 2013)

Brian Rupnow said:


> Okay--The verdict is in. I like the electronic ignition. The spark is constant and dependable, and it seems that as long as one follows the manufacturers instructions they are not as fragile as I had feared. The $105 was a bit hard to swallow, but that price included the battery pack and charger. If I build another engine, it will be cheaper ($85.00)  because I won't have to buy the battery pack and charger again. I'm absolutely sure that if I were to purchase components and wire up my own electronic ignition from components it would be cheaper still, but I really don't want to do that.---Brian



Hi Brian,
Gus now tempted to switch over to CDI for Webbie. You are right, spark from Jurassic HT Ignition Coil not as good as from CDI.
Will definitely go CDI for "Ruppy". 
Will also make same Hall Effect pickup adapter to advance/retard firing.
Tidal time & height no good this weekend.May stay back n play engine driver.


----------



## Brian Rupnow (Aug 16, 2013)

Luc--Now that I have a price ($85) from S & S engineering for a complete cdi ignition including a hall effect switch, magnet, and a silicone sparkplug boot but not including the batteries or charger, what do you think a comparable price would be to build basically the same thing from components?----Brian


----------



## canadianhorsepower (Aug 16, 2013)

Brian Rupnow said:


> a complete cdi ignition including a hall effect switch, magnet, ----Brian


 
Brian-- your probably looking at 10.00 at the most
and 1hr max of work. Here is the link and you could use a standard
car coil or a motor cycle coil

http://www.homemodelenginemachinist.com/f31/new-ignition-circuit-20415/index10.html#post229024


----------



## stevehuckss396 (Aug 16, 2013)

canadianhorsepower said:


> Brian-- your probably looking at 10.00 at the most
> and 1hr max of work. Here is the link and you could use a standard
> car coil or a motor cycle coil
> 
> http://www.homemodelenginemachinist.com/f31/new-ignition-circuit-20415/index10.html#post229024




How much is a standard coil? You also need to buy high volt wire, vacuum fittings for the spark plug boot and the spark plug. You kind of need to compare apples to apples.


----------



## Brian Rupnow (Aug 16, 2013)

In my end of the world, a 12 volt coil costs +/- $50 by the time you factor in tax at 13%. A high tension wire and silicone sparkplug boot runs about $10. So now we are up to $60 plus Luc's $10---Call it $70. Plus I still have to wire the components into a circuit. That starts to make the $85 I would pay Roy Sholl look reasonable.--(Roys price does not include the sparkplug either.)


----------



## canadianhorsepower (Aug 16, 2013)

stevehuckss396 said:


> How much is a standard coil? You also need to buy high volt wire, vacuum fittings for the spark plug boot and the spark plug. You kind of need to compare apples to apples.


 
I agree with you Steve,I should have been more precise,
the coil, HT wire and spark plug boots can all be picked up
USED in a small engine shop for ten dollars.

The reason I didn't mention them In the quote price 
is that I know Brian have some coil lying around in his shop
that he could use:hDe:


----------



## stevehuckss396 (Aug 16, 2013)

Brian Rupnow said:


> In my end of the world, a 12 volt coil costs +/- $50 by the time you factor in tax at 13%. A high tension wire and silicone sparkplug boot runs about $10. So now we are up to $60 plus Luc's $10---Call it $70. Plus I still have to wire the components into a circuit. That starts to make the $85 I would pay Roy Sholl look reasonable.--(Roys price does not include the sparkplug either.)



And also your time to assemble everything. You also need futaba connectors if you want things to be quick disconnect like Roys. They are 6 bucks and you need 2 of them. Then there is the physical size of the components. It's alot easier hiding the CDI board than a car coil. 

I made my own plugs for the V8 not to save money but because I couldn't buy them anywhere. It's not that hard but takes alot of time. I also know what it takes to make a mold and make spark plug boots and that takes a lot of work. Both of these things I do now because I have the tools and fixtures now and it does save a lot of money. I dont think I could build a cdi board that small with that hot a spark for 35 bucks or 50 with a coil. I think that the CDI board in the long run is cheaper and the other thing is, they just work great. 

Weather you buy one from roy or another source they are really a good way to go. I personally buy from roy because he is the one I see at the shows personally supporting the model engine building hobby. Plus if I can wait for a show to purchase what i need I can save on shipping. Not only that but he is one hell of a nice guy. Anybody who has ever talked with him knows that.

My .02


----------



## canadianhorsepower (Aug 16, 2013)

The best thing for you Brian is 
this kit from Roy, don't get me wrong I have nothing against them 
I was getting stuff from his father 30 years ago

a hall sensor is 1.20


----------



## canadianhorsepower (Aug 16, 2013)

stevehuckss396 said:


> And also your time to assemble everything. You also need futaba connectors if you want things to be quick disconnect like Roys. They are 6 bucks and you need 2 of them. Then there is the physical size of the components. It's alot easier hiding the CDI board than a car coil.
> 
> I made my own plugs for the V8 not to save money but because I couldn't buy them anywhere. It's not that hard but takes alot of time. I also know what it takes to make a mold and make spark plug boots and that takes a lot of work. Both of these things I do now because I have the tools and fixtures now and it does save a lot of money. I dont think I could build a cdi board that small with that hot a spark for 35 bucks or 50 with a coil. I think that the CDI board in the long run is cheaper and the other thing is, they just work great.
> 
> ...


 
Steve I don't think you need to jump on my head like a jack hammer:hDe: cause I answered a question, read my other answer
cheers


----------



## stevehuckss396 (Aug 16, 2013)

canadianhorsepower said:


> Steve I don't think you need to jump on my head like a jack hammer:hDe: cause I answered a question, read my other answer
> cheers



I'm not jumping on you. Don't think i'm trying to poo poo your ignition system. I was just trying to show the reality of building one yourself. Many guys including myself don't have a garage full of used parts so I have to purchase what I need. I agree that if you have access to used parts a lot of money can be saved. All i'm saying is if you need to source everything, the CDI is a good way to go. That's all.


----------



## canadianhorsepower (Aug 16, 2013)

> ]Don't think i'm trying to poo poo your ignition system.


.

It's not even mine it's one of the HMEM member circuit




> All I'm saying is if you need to source everything, the CDI is a good way to go. That's all


 
Hey I'm with you 100% on this one, but I prefer to build my own stuff
If I happen to do a f..k up I'll get a .25 cents part and not a complete module

cheers

how's that blower coming along??


----------



## Brian Rupnow (Aug 16, 2013)

I don't have any "used parts" either. I have to buy everything new, and the prices I quoted are for new stuff from PartSource right here in Barrie.  I just about had a heart attack when I bought my first 12 volt coil for the Webster 5 years ago. Damn---The last time I bought a coil was 1975, and it cost about $12. Now, as I say, they spoil $50. As far as buying used parts------When I build a new engine I have so many "uncertainties" that I just can't afford to buy something that may not be 100% "up to snuff". Luc--Don't take this as an indication that I am in any way beating on you, because I'm not. Its pretty obvious that you know your way around electronic stuff far better than I do. What it comes down to is that I would rather pay an extra $20 to get something that was "pre-wired" and foolproof, rather than put together a system that I'm not  sure of because of my own lack of electronic knowledge.


----------

