Ignition Opinion Question

[Naomi]

You folks were so kind as to troubleshoot the problem with my 79 MGB and determined the fault is the amplifier on the Crane XR700 Set-up. Thank you so much.

Now for the opinion question. The hubby spend his career as an electrical engineer but hates electronics. He wants to put a 25D Distributor on the 79 and that way it will be electro-mechanical (his words). A new one can be here in one day from Advance Auto for $66.00.

Would you let him do it and why? Would you not let him do it and why? /ubbthreads/images/graemlins/yesnod.gif /ubbthreads/images/graemlins/nonod.gif

Your turn

 

[kennypinkerton]

OK, I think I was the one who sent him that direction.... But, I think it's a good choice (and the price is fantastic!). If'n he's gonna go points only on it. You'll never have an electronics failure. But once every 3-15 years, he'll have to replace a set of $5 points on it. You might not get as smooth a running engine in a few years, but he can go to the driveway and file the points... and it'll run like it did a year ago!

I say it's a good move. But, Like I said, I'm probably the guy who moved him this way, so everyone post something please! Opinions needed!

 

[JoshP]

I've heard good things about the rebuilt 25D from Advance Auto or Autozone; I believe the name of the company that does those is called Cardone.

With that said, there's a couple of exceptions: the condensers that you get with those typically don't last all that long. You might consider replacing it right out of the box or keeping a good spare with you.

The other exception is the advance curve: those rebuilt dizzies are usually shipped with any one of a load of possible advance curves. Depends on what spring/weight combination that the rebuilder picks out of the box when he's doing that particular unit.

You can usually specify when you order which advance curve you want though. Someone here should be able to tell you what kind of curve you need to get.

 

[Naomi]

Advance Auto didn't say anything about rebuilt. Are they really just old ones that are rebuilt?

 

[JoshP]

I believe that they are rebuilts, but I wouldn't swear 100% to it. At the very least, they're old 25D bodies with new guts.

 

[rampant]

Yes all the 25ds are rebuilt. if i were going this route i would get a mallory, but the simple route is to go to a pertronix unit,your old dizzy is probably just fine its just the amp box bad.

 

[kennypinkerton]

rebuilt is better than a used one. It'll have new bushings, springs, etc. I say it's "the one"... But maybe a few othe opinions before...


is it still in the driveway down the hill?

 

[Naomi]

Kenny it's now safe and dry. The hubby and some friends pushed it up the driveway /ubbthreads/images/graemlins/smile.gif

 

[kennypinkerton]

Good. I was gettin worried. I spent today tearing down (not by much) my toyota so's I could replace the head gaskets. It got really cold around 3:30 and colder yet by 4:30 when I called it a day... and I'm 800-900 miles south of you. I can't handle too cold... Yes I'm a wuss. can't handle too hot either, or pain, or anxiety...etc.

 

[piman]

Hello Naomi,

I fully agree with your husband, but I would check first that the rebuilt unit is rebuilt to the correct spec for your car otherwise you would do better to find a good second hand unit.
There should be a few around, judging by the number of people who fit different makes of distributors to their cars.

Alec

 

[dklawson]

If you really don't like electronics the 25D4 is a good distributor to select as a replacement. It was used on so many LBCs through the early 1960s that you'll have no problem getting points and condensers for it. If the points do start giving problems later and you change your mind, the Pertronix unit for the 23/25 series dizzys is readily available and fairly well priced from sources like Retro-Rockets.

Visit Marcel Chichak's tech pages:
https://www.planet.eon.net/~chichm/tech.htm
and download his Lucas distributor database. You can search this PDF for which versions of the 25D were used in B's and perhaps choose a couple of curves to ask for when you order the part.

 

[DrEntropy]

/ubbthreads/images/graemlins/iagree.gif

The electro-mechanical diz is as reliable as a house brick. Naomi, your hubby is a keeper. He knows first-hand that eeelektricals and electronics are diff'rent animals. Anything as "delicate" as a PC board in an under-hood environ is WRONG from an engineering standpoint. Not a question of "if" but "when" it will go to it's knees... and it'll give NO warning in most cases. A set of points and condenser inna glovebox and you'll get home. For about ten bucks. Another "bene" is: if'n it'd pooped in the driveway with a 25D, he could yank it out and do the work onna kitchen table! Trot back outside and stuff it inna hole, crank it up and you're done.

<MHO>
Anything resembling a circuit board should not be a critical component in the running of an MGB.
</MHO>

 

[Bruce74B]

Naomi,

I have a rebuilt 25D from AA in my car with points. I think the the distributor has been there for about 8 years and the points are three years old. I am considering converting to the pertronix system, as it is plain and simple, but have not had any reason to do so in the three years that the points have been in the car. I have never adjusted them or filed them or even inspected them. SO I am of the opinion that it is a fine setup and why fix it if it aint broke?

Oh, by the way, the set I have in there now has been thorugh a leaking heater valve and a radiator leak without a single misfire from them. /ubbthreads/images/graemlins/grin.gif
Bruce /ubbthreads/images/graemlins/cheers.gif

 

[Bret]

Ok I guess I’ll have to be the one to chime in on behalf of Electronic Ignition. Now I’ve had many vehicles with points setups and I don’t have any real problem with them other than the fact that (as has already been pointed out) that you will have to replace & adjust them.

Now my 78B came with stock with Electronic igniton in the form of the 45DE4 CEI Distributor. It ran ok and by all accounts a vast improvment over the OPUS setup. But like many things over long periods of use I began to noticed that my engine starting to have some performance problems and seemed to be missing at the higher RPMs as well as some cold starting issues. Without going over the long list of items I adjusted, checked & replaced - lets just say I began to suspect there was something going on with the dizzy’s electronics module. But when I priced the CEI’s module it was hovering around $260 bucks a pop (today they cost about $300 /ubbthreads/images/graemlins/eek.gif ) anyway I didn’t feel comfortable laying down that kind of money on a "guess", so I went with the Pertronix Ignitor kit for about $98 bucks instead and while I was at it I also replaced the tired coil with a 1.5ohm flamethrower coil as well as new Bosch rotor, cap, plugs & plug wires. Once installed all I needed do is set the timing and forget it.

Results? Well it’s been over 6 years now and the only time I’ve ever had to pop off the rotor cap was to replace the cap & rotor and the one time I had a leaky heater valve that dripped right on top of the dizzy - but thats a story for another thread. Anyway today I’ll swear by the Pertronix units over any points system without hesitation.

In fact the only weak point I have to be concerned about now is the shaft of the old 45DE4 wearing out. Now I guess I could have it rebuilt or look for a replacment. But I’ve got another plan for my new “rebuilt” engine. I’ll be installing a new Mallory Duel Points distributor with the Pertronix kit installed. Also the Mallory’s curve should also work better with the modifications I’ve got planed too.

My $0.02
Bret

 

[lawguy]

If it will start and run half way decent when you drop fuel down the throat of the carb- no spark.

If it won't, probably no fuel. Primitive, but oh so effective.

 

[jlaird]

But but it is necessary to have an old Coke bottle for the fuel and stand back at arms reach. Hehe. Been there done that.

 

[Keoke]

[ QUOTE ]
Yes all the 25ds are rebuilt. if i were going this route i would get a mallory, but the simple route is to go to a pertronix unit,your old dizzy is probably just fine its just the amp box bad.

[/ QUOTE ]

Naomi /ubbthreads/images/graemlins/savewave.gif
I will chime in here too.When going from the old external amplifier electronic unit to the Pertronix, tell the hubby the reliability has to go up,because the parts count in the pertronix design is signifcantly less.Further,I am sure he is aware that the precursor to all electronic failures is a "mechanical one".Pertronix is reliability and simplicity at it best. Wear in the dizzy is also offset using this preferred component.--Fwiw--Keoke- /ubbthreads/images/graemlins/yesnod.gif

 

[Ralph_Y]

After fighting my points ove the last year- I went pertronix. The points would always change, thus did the timing and idle settings. The Pertronix cured the problem. Of course I do carry a spare ignition set up - just in case!

 

[Bruce74B]

[ QUOTE ]
If it will start and run half way decent when you drop fuel down the throat of the carb- no spark.

If it won't, probably no fuel. Primitive, but oh so effective.

[/ QUOTE ]

I think you meant that the other way around???

Bruce /ubbthreads/images/graemlins/confused.gif

 

[Keoke]

Yes Ralph_Y, spares are nice to have on hand. But you know what? I carry a spare Dizzy all set up with a Pertronix.It is so much simpler to swap out a Dizzy than fix one on the side of the road.Watch E-Bay and see if you can't snag a spare one at a reasonable price.However, I have not had to use the spare in the last 15 years---Fwiw-Keoke- /ubbthreads/images/graemlins/driving.gif