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Hagerty Employee

What I learned from testing the limits of an “idiot-proof” design

After my Austin-Healey's BMC A-series engine had left me stranded two times in as many weeks, I discovered that the points were more charred than a well-done steak at Golden Corral. So I sat down and ordered some parts and prepared myself for the task of playing with the ignition timing. That meant reading every manual I could find—I even dove into YouTube and absorbed everything I could regarding how to properly set up a new distributor.


I know what you are thinking, dear reader: Why is he replacing the entire distributor when all he needs is a set of points? Also, didn't Rob Siegel talk about this like two weeks ago? You are correct on both fronts, but hear me out. This article isn't an explanation of my choice to upgrade to an electronic distributor, or the exact how and why of the install. No, these are my thoughts about a word I used to describe the design of the BMC A-series distributor drive—“idiot-proof—and how it came back to bite me.


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Pit Crew

Three thoughts.


The offset drive of the distributer is easy to install correctly, even after the engine is built. A long 5/16 stud or bolt will allow the withdrawl of the drive and it is trivial to reinstall in the proper orientation.


You don't need to remove the valve cover to know the valves are rocking and you are on compression, just putting your thumb on the open spark plug hole and feeling the rush of air (or lack thereof) as you turn the engine will tell you all you need to know. From there it is 1342 CCW. And if you really mess up, knowing 1342 CCW allows you to get the right places in a maximum of four tries.


And finally, I can fix any set of points if needed on the side of the road. I can't fix a dead Pertronix... unless I carry spare points with me. Make sure your red and black leads INSIDE the distributor are not subject to wear and have an adequate balance of tie down and freedom because when the red shorts to ground you will melt the white wire from the coil all the way through the tachometer to the ignition switch.

Intermediate Driver

Wow, I couldn't agree more about the comments regarding driving at night with "Daytime running lights" on and absolutely no tail lights? How bonehead can you be to not realize the error. I think it does border on idiot territory. If you are driving a vehicle at night your dash lights will not illuminate whether you have said "Daytime running lights" or are driving an older vehicle. "Daytime running lights" are no excuse for not turning your lights on after dark. Well duh! You have no dash lights on.

If your vehicle dash lights don't do this, maybe you should find another vehicle to drive or another driving instructor.

Advanced Driver

In the mechanics book of "How to make my life Easier", rule #1 is to mark everything. After 50 years in that world, I still use rule #1 almost every day. Blue painters tape and a black sharpie are still my personal favorites.


For every "Better" design, there are better Idiots ! 😉



Intermediate Driver

My favorite corollary to Murphy's Law is this: "It is impossible to make anything foolproof because fools are so ingenious!" 

Not only do I believe this, I have proven it true many times. :~)

Pit Crew

I'm not clear on why it mattered where the rotor was pointing when he took the dizzy out....just put the new one in the EXACT same way and no problem. It's when he must have decided to check and moved the crank that he made his own mess. I've replaced dozens of distributors with the rotors pointing to any of the  360 degrees and have never had an issue with start up.


I just put the damper on TDC and restab if there are any issues. Otherwise, like you said, just make sure you have the rotor pointing in the same direction, start it, and recheck your timing. That being said, I have been guilty of not paying attention to WHERE the rotor was pointing.
New Driver

thanks for this it really helped