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MG MGB Technical - This Should Be Easy....Pertronix Help Please

I justed installed a pertronix Ignitor in my Brit-Tek
Lucas 45D "Euro-spec" distributor. I verified that the Ignitor is the correct LU143 model used with this dizzy. The fit of the breaker plate is fine. The collar seems to fit (as far down the cam as possible), but the rotor now sits too high for the distributor cap to fit. Has anyone else seen this problem? All suggestions (other than go back to using point!) would be appreciated.

Thanks,
Jeff
Jeff

Jeff. Recently, a fellow member of my MG club tried to fit a Petronix to his Lucas 45D distributor. His chopper would not fit onto the points cam properly. The chopper should fit down far enough to provide a significant space between the top of the chopper and the rotor. Did the rotor fit with the points in place, or are you using a new rotor? The chopper plate or the rotor seem to be the problem. Does the chopper fit down so the top of the points cam and the top of the chopper are level with each other? If not, that is part of the problem. Les
Les Bengtson

Les,

Not certain what the chopper refers to. AKA breaker plate? Sorry I'm a novice. The rotors sits higher with the Pertronix collar in place. It fit fine without the collar. Perhaps a shoter rotor is in order?

Thanks,
Jeff
Jeff

Jeff. The chopper is the collar. Its purpose is to "chop" the beam of light. The chopper/collar should fit sufficiently low enough to allow the rotor to fit properly. My friend had a very similar problem and had to go to a Lucas 25D4 because the Petronix kit for that model would assemble correctly and work. If the Petronix kit required a "shorter rotor", i.e. a rotor that is less tall than the factory specification, it would have been included in the kit. Since it is not, it indicates the kit is designed to work with the factory parts. Re-install the points if you need the car on the road, then contact Petronix to see if they have any advise. You might mention that you have been informed, through this BBS, that other people are having similar problems with the 45D4 kits. Les
Les Bengtson

Jeff, I have Crane systems on my two MGB's and the shutter disc causes the rotor to sit a little higher. I found that some after market distributor caps made by Intermotor will cause the the rotor to bump the inside distributor cap terminals. The Lucas caps I have seen have thinner inside terminals and work ok with the Crane system. My distributors are D25 not D45 but Lucas caps solved the problem for me. That may not be your problem but it's worth checking. Good luck, Clifton
Clifton Gordon

Jeff, your Pertronix is magnetic, rather than optical, but Les is right -- the collar should sit down low enough that the rotor should fit normally. As I recall in my 25D4 distributor, the rotor actually touched the collar, but it (the rotor) did not sit any higher than normal. Verify that you've got it installed properly (just to make sure), and then do as Les suggests and call Pertronix. You should not need special parts to make it work. Indeed, if it took a special rotor, I wouldn't want it -- what happens if the special rotor were to become unavailable?

HTH!
Rob
Rob Edwards



Thanks for the advice. This BBS is great.

I'll give Pertronix a call...and maybe get another cap.
Jeff

Ditto a different cap. If the Pertronix doesn't fit without having to change something else on the dizzy, or even having to mangle the points plate as I have heard in the past, it is crap. Even if it *does* fit, and work, always carry points and a condenser as a spare. Points may wear over time, but they and the condenser are much less likely to catastrophically fail than any electronic system. I have never had either fail in over 35 years of driving, and since using dwell to check the points gap neither do they need adjusting at every service.
Paul Hunt

I have four distributor caps, you would think they would all be identical. A new one that came in a Lucas box, no markings on the cap, has about 50% of the terminal diameter cut away. The terminals are .295" tall. Another unmarked spare has about 25% of the terminals cut away but the terminals are only .255" tall. The cap on my GT has about 1/3 of the terminals cut away and terminals are about .260" tall. The cap on my 74 has about 2/3 of the termanals cut out, I didn't measure the height of the terminals.

My experience with points dates back to around 1944 or 45 and I have experienced several condenser failures, two in one 53 Plymouth I owned. I don't recall ever having a set of points break but have had them pit and oxidize enough to fail. The last set of Lucas points I bought did not have enough adjustment range to set the gap, had to work on them with a file. They looked like the points I removed andhad the correct part number for a 25D4 distributor but wouldn't fit without altering them.

FWIW, Clifton





Clifton Gordon

This thread was discussed between 06/07/2003 and 09/07/2003

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