Electronic ignition vs. Old style points and coil

[Brian Rupnow]

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]

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]

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

 

[stevehuckss396]

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]

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

Paul.

 

[canadianhorsepower]

[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]

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]

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

In the past I have used the Honeywell SS443.

 

[stevehuckss396]

In the past I have used the Honeywell SS443.

Sorry that would be a SS443A

 

[canadianhorsepower]

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]

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

Ron

 

[canadianhorsepower]

Sorry that would be a SS443A

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

 

[canadianhorsepower]

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

 

[ozzie46]

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]

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]

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]

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

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

 

[canadianhorsepower]

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]

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]

Here is the page, see what you think.

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