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MG TD TF 1500 Help with Pertronix connection on XPAG BBS discussion at MG-Cars.net
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MG TD TF 1500 - Help with Pertronix connection on XPAG
| Got a new pertronix for my '52 TD. Pos. ground. I have the Moss-supplied high output coil, that is marked + and -. I did have the + going to the ignition, and the - going to the dizzy....(based on previous research on proper connections of the coil).... Anyway, the Pertronix instructions say to connect the solid black wire to the ignition switch wire, the bw wire to the - coil terminal, and a new wire, from the + coil to ground (or + batt)... So the question ....Is this the way everyone has connected the Pertronix? I don't want to fry my ignition. Thanks for any additional input.... Edward |
| E.B. Wesson |
| curious as to what others post, convention has in a pos grnd sytem the + going to the distrubutor. regards, tom |
| tom peterson |
| Ed, see http://www.ttalk.info/Tech/PerPosGndWiring.htm. Follow the Pertronix wiring diagram. DO NOT green thumb it! The wiring of a positive ground Pertronix unit is different from the wiring of a conventional ignition. Bud |
| Bud Krueger |
| ...and you only have one chance to hook it up correctly.... |
| gblawson(gordon- TD27667) |
| Follow the directions and Bud's advice. Think you had your coil installed backwards before. George |
| George Butz |
| George Just so you don't think I'm "upside down" , here's a quote from the magazine for Plymouth classic car owners, called "PlyTech": "Please note that the + and - coil terminal designations have nothing to do with the battery polarity. It has to do with the phasing of the coil magnetic windings. In transformer parlance, "-" designates the start of the winding and "+" designates the finish of that winding. Many mechanics incorrectly believe that these symbols refer to the battery polarity. Ironically, when they connect the + coil terminal to the ignition switch and the - coil terminal to the distributor points in a negative ground car, it is correct , although for the wrong reason! These same mechanics connect the + coil terminal to the distributor points and the - coil terminal to the ignition switch in positive-ground car, result in having an INCORRECT phasing of the coil. This is why many antique Packards, Cadillacs, Chryslers, Fords, and other positive-ground cars have their coils connected in reversed polarity, and have poor ignition performance." This article was submitted by the Technical Director of the National Plymouth club. (Earl Buton Jr.) Bud Thanks for the confidence builder...I was not going to do it without making absolutely sure it would be correct. Edward |
| E.B. Wesson |
| Interesting quote, never knew that. Further research found this from MG expert Carl Cedarstrand: http://www.guy.weatherall.dsl.pipex.com/ht/coil.htm Seems there is an acutal internal difference in positive and negative ground coils. So it depends on which kind of coil you have. That means I may have driven the TD for some years with a backwards coil? Whatever, I would still follow the Pertronix directions. George |
| George Butz |
| George, me too. I have the pertronix and the old coil and it works fine. I just folowed the pertronix instructions. I did wire it so that I could run points if the pertronix ever goes out. |
| Tom Maine (TD8105) |
| Drove the car about 20 miles , today, using the new Pertronix, wired as per instructions....Car ran fine... Biggest surprise, was the change in timing, after installation. When I did my two "B's", ignitions, there wasn't enough timing change to matter.... When I did the TD, the change in timing was +24 degrees more, to the advance side! In other words, total timing went to 34 degrees, at idle....Wow!.... Frankly, I'm amazed that I even got it started... I usually run at 8 degrees BTDC.... Edward |
| E.B. Wesson |
| Ed, how are you measuring the timing? Bud |
| Bud Krueger |
| Bud I have an Equus electronic timing light....I can set the digital timing number, until the timing marks line up...This tells me where the timing actually is...no guessing...Then I set the light where I want it to be, and move the dizzy until the mark lines up... I am running at 8 degrees.... It's one of those tools that I couldn't do without. Edward |
| E.B. Wesson |
| Fine, Ed. Just don't try the usual static timing with a positive ground Pertronix. Bud |
| Bud Krueger |
| When I put a pertronix in my B I had to advance the timing. Not sure how much, just did it listening to the rpms. Rorated the dizzy to max rpms till it started to sputter then backed off till idled smooth. Tightend it down and ran like never before. Dan H. |
| Dan Hanson |
| I coupled up the Pertronix as per the instructions from MOSS in my pos. ground TF this spring. Adjusted the ignition to 4 mm before TDC at idling speed with strobe light, and then by ear and feel over the next week. Points and condenser is history to me. |
| Jan Kristoffersen |
| edward, i have read too many articles by a number of professional mechanics and mechanic instructors to give that article any credibility. milton webb is one who comes to mind. regards, tom |
| tom peterson |
| Give Jeff at Advanced Distributers a call. He can tell you all you need to know about the Pertronix installid in our cars. |
| Tom Maine (TD8105) |
| Thanks for the comments, guys.... This is my third Pertronix, but the first in a TD, other two were B's.... I love them....Car is running great... Now , all I have to do is figure out some small issues with the carbs... Not enough to get excited, just enough to aggravate. Tom Well, goes to show you that even experts have differences of opinion.... A local car club (large), President, gave me the article, when I was asking about proper hook up... I have to say that the ignition worked fine that way, with the points...Never showed any hesitation, etc.... Many of the cars in that club, though not British, are positive ground cars, and they are all hooked up like the article...... Edward |
| E.B. Wesson |
This thread was discussed between 28/09/2011 and 29/09/2011
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