pusherman Posted February 19, 2014 Share Posted February 19, 2014 hey gota get a new condensor for the escort seeing as i blew my electronic ignition cos i wasnt paying attention in class. obviously ive got to get the correct 1 to fit my lucas 43d dizzy buuut is there different grades types? im kinda thinking along the lines of hot and cold plugs, lots and little condensing? once again thanks for tolerating my bulshit questions. Quote Link to comment Share on other sites More sharing options...
CaMpylobacter Posted February 19, 2014 Share Posted February 19, 2014 tbh this interests me (and I'm sure a quick google may net some results but i like people putting things into a real persons terms) also, in all honesty I've never even taken the time to learn what they actually do on points distributored cars, rather, that I just know they're a service part/you car will run shit if it's fuxt and that's how I've left it lol 1 Quote Link to comment Share on other sites More sharing options...
peteretep Posted February 19, 2014 Share Posted February 19, 2014 I would also like to know the only thing I really know about condensors is that if the spark is yellow instead of blue, then your condensor might have crapped itself, and that they are there to stop electrical noise or something Quote Link to comment Share on other sites More sharing options...
pusherman Posted February 19, 2014 Author Share Posted February 19, 2014 im sure answer are on google but like you say some on here will have played and around with them and know what 1 works best. im sure the condenser would play a part in the dwell of the coil/charge/ignition. i spoke to Murray at Weber specs because i need a tune and also mentioned i have a misfire shittyness at about 4000rpm and he said replace condenser first then coil. so should it be the condenser causing my misfire, is there a better rated 1 to a modified motor, if a standard motor revs to say 5-6000 and a worked motor revs to 7-8000 surely there needs to be a change in the spark creating side of the ignition. Quote Link to comment Share on other sites More sharing options...
phr34kr Posted February 19, 2014 Share Posted February 19, 2014 I started to look into this a little while ago when the Scimitars condenser gave up and had to get it towed home. This site leads me to believe there are different quality condensers on the market? http://www.distributordoctor.com/distributor_condensers.htm No idea about the different values question, although my workshop manual gives me tolerances and a value the condenser should be within. Quote Link to comment Share on other sites More sharing options...
Nominal Posted February 19, 2014 Share Posted February 19, 2014 "Almost all automotive coils use a 0.25-0.29 microfarad capacitor." Random google result. They are just a capacitor. I can't imagine that there is much difference in the actual mFD rating of them. Could totally be quality differences though. I've always understood that they basically stop arcing at the points, so the value won't matter very much, so long as they achieve the objective. Quote Link to comment Share on other sites More sharing options...
Ned Posted February 19, 2014 Share Posted February 19, 2014 Fuck I hope I don't have this wrong haha. The points switch the - of the coil to ground. The condenser (cap) is connected between across the points. So when the points close, the cap discharges as both sides of the cap are connected to ground. When the points then open, the primary winding wants to keep flowing current as its a winding of coils and will jump the points gap and burn the points, as the arcing of the jump will kill them. This is where the cap comes in. A discharged capacitor acts as a direct short circuit until it's charged, so when the points open, the condensor actually keep a the - of the coil at ground and allows current to flow through the cap and allows the points to fully open so no arcing happens. The cap will now charge up, and no more current will flow through primary and no arcing will happen. When the cap is too big, it will take longer to charge and longer for the spark to happen. If it's a massive cap, it will probably even stop the secondary from creating a good spark voltage and you will have a shit spark. If the cap is too small, it will not be able to take enough energy and you will still have some arcing happening. On top of that, when a mechanical switch (like points) close, they won t actually close properly first time, they bounce on and off the contact a couple times (imagine like you dropping a ball, it will bounce a few times before it stays on the floor) and because a capacitor acts as a direct short when you close it, it will keep current flowing steadily while the points are bouncing around and not keeping a steady flow going. Plus, if the points bounce without the cap, you will get a bunch of arcing every time they bounce and will burn your points. Hope that made sense, and I hope that's what it's actually for haha 4 Quote Link to comment Share on other sites More sharing options...
pusherman Posted February 19, 2014 Author Share Posted February 19, 2014 Velly interesting. Could make sense as at medium high revs my misfire happens which could be the capasitior/condenser not holding its charge and arks are flying around all over the show. So i neeed the next size up ...... Or down? Quote Link to comment Share on other sites More sharing options...
Rookie Posted February 19, 2014 Share Posted February 19, 2014 I didn't really read that Ned, but you are wrong. All the condenser does is suck up the juice from the secondary coil collapsing inducing a voltage in the primary coil. It is this voltage which burns out points. Quote Link to comment Share on other sites More sharing options...
Rookie Posted February 19, 2014 Share Posted February 19, 2014 I did read that Ned and you are definitely wrong. Also the points don't bounce when they close because the natural frequency of the return spring is such that they are opening again before they have a chance, also, as soon as they touch the primary coil collapses inducing the secondary coil/ spark. To answer your original question, they are all the same and it is the mounting that is different. Get one that fits and you will be gravy. Quote Link to comment Share on other sites More sharing options...
Rookie Posted February 19, 2014 Share Posted February 19, 2014 Also if you want a condenser, or any Lucas parts for that matter ring Hawkswood Classics, I have had really good dealings with Matt. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted February 19, 2014 Share Posted February 19, 2014 Just saw this now but handsome Dave is right. Condensors are the same in how they work but they are different in mountings and how they hook up to the points. Kinda like saying are all wheel bearings the same. However you could much more easily adapt any condensor to a dizzy if you had some basic tools. In saying this some have different microfarad (sp?) ratings - but I would be surprised if you cannot get the exact ones you need with no modification required from somewhere within NZ in 2 days tops. 1 Quote Link to comment Share on other sites More sharing options...
Ned Posted February 19, 2014 Share Posted February 19, 2014 I'm sorry dave, but i AM right. Google "points bounce" and you'll see i'm right. And as per you saying im wrong about my first point, well, an inductor stores energy and when you open up the switch, it does some magic stuff that means it will continue to flow electricity which would cause an arc but thats stopped by the cap as the cap takes the arc... doesnt really have anything to do with the collapsing secondary winding 1 Quote Link to comment Share on other sites More sharing options...
Rookie Posted February 19, 2014 Share Posted February 19, 2014 Ned, it has everything to do with the secondary winding. Don't make me get your signature changed. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted February 19, 2014 Share Posted February 19, 2014 Points bounce is when the dizzy is spinning faster than the points can handle - essentially the same as valve float. If points do bounce on closing it is probably an absolutely smaller than minute amount and effectively negligible amount so not even a factor. 1 Quote Link to comment Share on other sites More sharing options...
Ned Posted February 19, 2014 Share Posted February 19, 2014 Physical switches bounce, it's just the way it is. The bouncing doesnt cause sparks because the primary winding hasnt had enough time to build up enough energy to induce the secondary, but it is capable of arcing, and it sure doesnt help with getting a steady spark as the inductor on time will vary quite a bit. It's minuscule, sure, and its not the primary reason for the cap to be there, but it's a happy by-product. 2 Quote Link to comment Share on other sites More sharing options...
slacker.cam Posted February 19, 2014 Share Posted February 19, 2014 Just to clear up some confusion here. Dave's not entirely correct. Not all condensors have the same capacitance (as KK suggests). Now I'm not sure how you know what value you want for a specific application but there're definitely not all the same. 1 Quote Link to comment Share on other sites More sharing options...
slacker.cam Posted February 19, 2014 Share Posted February 19, 2014 I didn't really read that Ned, but you are wrong. All the condenser does is suck up the juice from the secondary coil collapsing inducing a current in the primary coil. It is this current which burns out points. 1st sentence = Ned's not really wrong at all. His description is just more technical than the level you're thinking about it at. 2nd sentence = Wrong. You have this upside down. When the points open the primary side collapses and this induces a voltage in the secondary. Along with the voltage being induced in the secondary you also have back EMF which creates a large (negative) voltage on the primary side (across the points). The condensor sucks up some of this back EMF energy and therefore reduces the arcing that eventually burns out your points and creates noise on your stereo. 3rd sentence = Also wrong. The current doesn't really matter. It's the high voltage in the reverse direction that creates the arcing that burns out points. I just want to make sure we have the tech straight. I know it's not really relevant to this thread but some of the stuff up there ^^^ is pretty misleading. 1 Quote Link to comment Share on other sites More sharing options...
Rookie Posted February 19, 2014 Share Posted February 19, 2014 Read what Ned said and come back to me, it is wrong. I will conceed that you have me on point three, I got sloppy with my terminology, but the rest of what I said is correct, and actually we are talking about the same thing, it is the back EMF that is created by the secondary coil inducing the primary coil that causes the arc. Quote Link to comment Share on other sites More sharing options...
fishtailfred Posted February 19, 2014 Share Posted February 19, 2014 Ned and slacker.cam are on the game here. I don't run a condensor at all This is the best way NO POINTS. Points suck, for many reasons, bounce included (yes it's real). You can solve some of these reasons with one of those old fashioned transistor ignition boxes which pass a little current through the points to keep them clean and switch the coil hard with a transistor! You can solve even more of the suckiness by having fully mappable ignition. Yay for rev limiters. OT now, sorry. I hate dizzies, and I hate points even more than dizzies. But the above tech by slacker and Ned is pretty much right on the money. I'd say Ned's longer post was very well written, in fact. 10 out of 10, Ned. Quote Link to comment Share on other sites More sharing options...
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