Boatist.....your opinion please

[cc lancer]

OK Boatist<br />Here goes, I'm going to keep this simple so the non-electrical gifted can follow.<br /><br />In the split second that the ignition goes to ON position the coil is energized, the voltage goes to <br />the condensor and it is energized.<br />the key hits the start position, and the engine turns over, the points close and up to 45,000 volts goes to the spark plugs.<br />1. The condensor has received the full voltage from the coil correct?<br />2. Since Mr. Lux said that 300 to 400 volts can arc open points, would this amount of voltage be stored in the condensor?<br />3. I never paid much attention to this component in my life, can it deteriate with age like any other capacitor?<br />4. Since it runs hotter in a boat than in a car, would its life expectancy be shortened?<br />5. During the boating season, this component sees a lot of use, and abuse, gets a 5 month break<br /> then the cycle starts over again.<br />6. So in your opinion should this item be changed yearly?<br />7. As the rotor goes from distributor terminal, to terminal, is not the stored energy in the condensor<br />depleted and must be recharged by the coil?<br />Yes I know that they can last a long time in cars, but when I talked to some of the old Grand National<br />guys, I was informed that a points ignition system was never designed to be used in high RPM applications, that the auto makers designed this item for the grocery getters running up to 2500<br />RPM. After each race they would install new points, condensor, coil, some even doubled the springs <br />from old points to control bounce. <br />One old book I read said that condensors can partially fail, [this you and I know] could this reduce<br /> the voltage to the plugs, and stop the engine from attaining it full RPM yet everything else on the engine checked out OK? <br />[There was even some type of machine invented to check auto condensors.]<br />Over the years I have seen engines where every thing was as perfect as humanly possible, yet I could not get the full RPM's out of the engine. Engine cranked perfect, dwell was on the money, plenty of fuel and pressure, compression perfect, but for some little reason the engine would not<br />attain its RPM potential.<br />What do you think ? Is this an over looked item when trouble shooting full RPM potential?

 

[JFLS40]

Re: Boatist.....your opinion please

Gosh, I don't have an Electrical Engineers Degree for that answer...

 

[qaztwo]

Re: Boatist.....your opinion please

I think you are looking at the coil the wrong way. The coil is used to take 12 volts or what ever is sent to it and step it up. The points are only used to collapse the field around the secondary coil. When the field around the coil is collapsed, by the points, the secondary field is energized and the end product is a spark.

 

[Boatist]

Re: Boatist.....your opinion please

CC Lancer<br />I think the points in a standard setup last a very long time and works good. As a Example in my 1980 3.0L 140Hp I have only changed the points and condenser one time. I had no problem with them but after 15 years just seemed like the right thing to do. I alway carry a new spare in my onboard tool box but also keep the old set for a second spare. I have seen the condensor fail in a car and a lawn mower. Each caused a weak spark but still ran. Also in a car I have seen and bad condenser cause the points to get a build up on one side of the points. If it is too big one side builds up and too small the other side builds up. <br /><br />In boats we had one a couple of months back that stopped the engine from going over 2200 RPMS. With a dwell meter hooked up the dwell would change and the engine would miss fire. What caused it was guy changed his points and condenser on a engine running good. After he changed them he could not get over 2200 RPMS. The reason was when he put in the new points he put the ground spring on the wrong post. This spring is what supplies the pressure to close the points. At the higher rpms the points would not close fast enough to follow the points cam lobes. Once he hooked it up right it was fine.<br /><br />In a car I saw one guy who had a problem with points build up on one side. He changed the condenser and points and still before long same problem. What it turned out to be was he had changed the standard coil to a supper coil. The supper coil really did not improve anything so he put back the orignal coil and all was good.<br /><br />I not sure condenser runs any hotter in a boat. My Chevy truck has the distributer at the back of the engine. The engine is a V8 350 ci engine. The engine temperature is 195 degrees. Since it is a V8 the spark cycle happends 8 times per reveloution where as my 3.0L it is only 4 times. So if I wind my truck up to 4000 RPMS it like winding my boat up to 8000 RPMS. The boat Temperature is 150 to 170 degrees. I must admit I not one to run my boat at WOT in fact rarely go over about 3200 RPMs.

 

[qystan]

Re: Boatist.....your opinion please

Correction on this bit.<br /><br />Quote<br />"In the split second that the ignition goes to ON position the coil is energized, the voltage goes to <br />the condensor and it is energized.<br />the key hits the start position, and the engine turns over, the points close and up to 45,000 volts goes to the spark plugs."<br />Unquote<br /><br />1. The coil is energised when the ignition is turned on but current only flows through it when the contact points are closed. The current through the coil creates a magnetic field.<br />2. With the points close, the capacitor is shorted out and receives no voltage.<br />3. When the points open as the engine is turned, the current flow through the coil is interrupted. Without the current, the magnetic field collapses to zero. This collapse generates a voltage across the coil and is applied to the contact points.<br />4. In the absence of a capacitor, the high voltage can (most likely will) cause the point gap to arc as the voltage tries to create a current flow.<br />5. With a capacitor, it provides a path for this current and absorbs it, essentially stops any arcing.<br />6. The capacitor path is also far easier current path than the air gap across points, this helps the collapse of the magnetic field.<br />7. A more rapid magnetic field collapse creates a higher voltage.<br /><br />Discussed above talks about the part of the coil that gets the 12V (Primary). A second (HT) coil with many more windings do not get the 12V but gets the effect of the magnetic field collapse and this coil is what generates the HT spark.<br /><br />The capacitor is subjected to positive and negative charges across the electrodes and there is cyclic attraction forces which occurs with each spark generated. Since marine engines run at high rpms, it is subjected to much more physical stressing cycles than that in a car and we should expect more failures in this application but it should still last a while.<br /><br />Capacitors fail either shorted or partially shorted. With a full short, you'll get no spark (same effect as if your contact points never opens). A partial short prevents a full coil current interrupt, so you get a partial magnetic field collapse = weak spark.<br /><br />Looking at the electrical circuit diagram for a reversed coil connection. In addition to the usual effect described above, the spark HT discharge will generate a reverse polarity pulse in the Primary 12V coil and will be applied to the capacitor. Capacitor reverse polarisation is a no-no.<br /><br />If my 30 years ago memory cell is till intact.....

 

[f_inscreenname]

Re: Boatist.....your opinion please

Throw that crap (points and condenser) in the trash and get yourself a Pertronix Ignitor kit (www.pertronix.com). The best $70 bucks you can spend. Many here have used them and I haven't herd of any problems just how much they love it.

 

[ronjon444]

Re: Boatist.....your opinion please

I changed my old points and condensor over to the the Pertronix Ignitor kit and will never go back. Installation takes an hour max, set the timing and your done. Best $70.00 I have sepnt on the Mercruiser 260.

 

[Scaaty]

Re: Boatist.....your opinion please

Have blamed everything BUT the condenser on a 79 Harley misfire after 20 minutes, a 73 Sportster when warm, and 1977 350 boat that would run for 10 minutes and loose power and quit. Now I replace the cheap items first.<br /> And agree with Pertronix, but the II model so ya don't fry it when ya leave the key on, and if you do the new coil and wires and plugs, its a lot more than $70 though, in fact just short of a new electronic ignition system complete with new distributer...IMHO<br />Ps. Qystan has the correct answer.

 

[KaGee]

Re: Boatist.....your opinion please

Originally posted by f_inscreenname:<br /> Throw that crap (points and condenser) in the trash and get yourself a Pertronix Ignitor kit (www.pertronix.com). The best $70 bucks you can spend. Many here have used them and I haven't herd of any problems just how much they love it.

THEY DON'T MAKE ONE FOR MY BOAT!!!!

 

[Peter J Fraser]

Re: Boatist.....your opinion please

Nor mone KaGee.<br />But I've got a smart buddy who is an auto electrician and we will convert my distributor to solid state soon. <br />Regards<br />Peter

 

[Boatist]

Re: Boatist.....your opinion please

Pertronix has left hundreds stranded just because they left the key on too long. If you want to go electronic make sure it is Pertronix II.<br /><br />I have never had a set of points and condensor leave me stranded in my car or boat. I know some have had problems. I have seen the Pertronix II installed and saw no performance difference.<br /><br />I carry two spares set of point and condensor in my on board tool box, never seen a points or condensor failure on any of my boats, I/O or Outboard. If one in the I/O should fail I could change them and be back under way is less than 10 minutes with nothing but a screw driver. I dout anyone carries a spare Pertronix II in there tool box. I hope most keep the old points and condensor and instructions in case the Pertronix II should fail. It seem to be solid but I know several left stranded with the first model.<br /><br />If you got 10 more HP or better fuel mileage then I might try it. But one I saw made no difference.<br /><br />When I am in the ocean and 25 miles form nearest port I like to know I have lots of ways to get back. Sure the 15 HP kicker can get you back in 7 or 8 hours if your have enough fuel.