ignition issue

[ozzie46]

Built Steve Hucks Lil Demon and am having issues with the hall effect sensor being ruined. I use a 12v batt and a dsage ectronic setup that I use on my 4 cyl. it works fine on the 4 cyl, but fries hall sensors on the Demon distributor. Could the small size of the Demon dizzy cause issues when using 12v?
the 4 cyl dizzy is almost 2in dia. the demon dizzy aprox 1in dia.
I got hall sensors From Roy Sholl.

Ron

[Don1966]

Ron if you used it on the same system as before it souldn’t fry it. The hall sensor has a max current drain as long as you don’t exceed that it should work fine. Check your connections again and make sure the ignition ground is good and none of the cables are close to the high voltage lead.


Regards Don

[Bearcar1]

Ozzie, I can not speak to the size factors of your distributor, but I seem to recall an article I read that outlined the proper pole of the magnet facing the hall effects device as being a factor of its operation. As I remember, the "S" (South) pole of the magnet was required to face the Hall device. Just some more food for thought.


BC1
Jim

[gbritnell]

Hi Ron,
I have made distributors large and small using a Hall trigger. The only time I've ever had problems burning the Hall transistor was from poor grounds. I have had the same Hall in my 302 V-8 for years with no issues. When I built my flathead V-8 I must have burned out 5 of them. My problem wasn't a bad ground but rather I tiny uninsulated area of wire where the Hall lead was soldered to the extension wire. I just happened to be running it one day, thinking that it would burn out at any time, and I noticed a tiny arc from the solder joint to ground. I modified the connection and now have about 3 hours running time on the engine with no problems. I would suggest you just go over all your connections and grounds. Steve takes his to the show and runs it for hours with no issues so the design shouldn't be a problem.
gbritnell

[stevehuckss396]

I never rely on the tiny ground wire on the transistor board. I always solder a 16 wire onto the negative side of the coil and bond it to the engine. When you have a bad ground the high voltage looks for another path. Usually that path is the hall sensor wifes. The 16 wire properly soldered and bonded to the engine gives a much better current path and reduces the likelyhood of sensor failure.  Like George said, I run mine quite a bit and still have the original sensor from when it was built. I did have a sensor get lazy on the peewee so it would start but not rev up. But even that one never completely failed.

[ozzie46]

Thanks for all the replies. Jim, the south pole is used to activate the sensor.

Don and George I will double check all my wires. Steve I do have a larger wire on the coil and chassis grounds.

Here is some more info I should have mentioned ,  if I touch the Demon V8 dizzy. Then the sensor fries, it seems, at that point.

An AHHA moment! It happens when I am trying to start the engine with a drill and I try moving the dizzy to find the sweet spot of timing. One hand on drill the other on the dizzy, could I be the ground frying the dizzy?


 Ron

[ozzie46]

 George did you ever post a video of the flat head running? If you did I missed it. I followed the build thread til you took a break to from trying to get it running. Do you have link to a vid?

As always on your builds it was awesome.

Ron

[Charles Lamont]

What is "16 wire"?

[Jasonb]

16 gauge, that's AWG and equates to about 1.3mm2 which is a lot heavier than the wires that go to the sensor.

[gbritnell]

Hi Ron,
Here's the video of the flathead running. When I made this video I had made an adapter for the dual carb manifold to use 1 carb. Since then I made another complete manifold for a single carb. My plan is to get it running and adjusted as good as possible before going back to the dual carbs.
gbritnell
<a href="https://www.youtube.com/watch?v=694CKZlDyzg" target="_blank">http://www.youtube.com/watch?v=694CKZlDyzg</a>

[stevehuckss396]

I read that you get a tingle when you touch the distributor. That is a pretty good indication that you have a poor ground path. I cant remember ever getting a jolt of any kind from my engines. Make sure you scratch off any paint so the ring terminal is sitting on bare metal before tightening. That could also be a sign that the spark is not making it thru the distributor and jumping to the body of the distributor.  Double check where the conductor on the rotor is when the ignition fires. Be sure its aligned with the contact you want it to jump to and not somewhere between 2 contacts.

[ozzie46]

Steve, my distributor cap is machined from white delrin and I can see a large spark sometimes in side the cap. Will double check ground connection.

 George that sounds and looks great.

[ozzie46]

Turns out the engine is pumping oil up the cyls. I used viton O-rings instead of cast iron. Never had an issue on my other engines that use them. I may have to remake cyl liners, so ignition is on hold for awhile.


Ron