The Scientific Method

What it is: The scientific method starts when you ask a question about something that you observe. That's what google tells me anyway.

I bought a Pertronix coil some time back. I wired it in just to see if it worked. It did. I took it out, put it away for a later install date.

Just put the coil in today. Installed as instructed...bypassed the ballast. I have it mounted on the passenger side inner-fender flat. That's where my Acell 140001 has lived for decades.

Ran the car for a bit, checked the timing, hooked up a new diagnostic tach, did some carb adjustments.

That's when 'The Question' came up. I felt the Pertronix...and it was hot as hell!! 150º as measured with my non-contact IR gun. I didn't expect that...the coil having over TWICE the primary coil resistance the Acell has I figured it would sink considerably less current.

I patched the Acell back in, simply sat it a bit further back on the inner fender. I ran the car for the same amount of time I'd run the Pertronix. Checked the Acell; it was 120-130º. AHA! The Pertronix is just running too damn hot!

Here's the punchline: I happened to put my hand on the disconnected Pertronix. It was still/again too damn hot! Checked it with the temp gun...150º!

Huh?

Common sense would tell you that an operating coil would be warmer than a non-operating coil. Common sense MIGHT also tell you that if a coil ran cool under use but just happened to be sitting in a HOT place...you couldn't tell the difference between its operating temp and its 'just sitting there' temp!

And there 'ya go. What I observed told me that the Pertronix was running hot. That it was sitting adjacent to #4-6 header pipes (MUCH hotter than #2 or #8) didn't enter my mind. That's where the coil has been for many years.

Who cares about this silly story? It probably interests about zero persons. BUT...it should give the reader pause to consider how they observe things and the conclusions they come to. The Scientific Method did not work in this case. Why? Because I didn't follow it!!

Science is mostly failures. You observe something, you "test" it, you get a result you didn't expect. Technically your test failed, but really science just showed you all the ways your original test was flawed.

In this case, you discovered an additional variable you didn't originally account for (heat from the headers), and unintentionally added an additional variable (moving the coil to what may be a cooler location)

Now, if you swap the coil locations and check the temperatures of both coils again while operating them and not, you may discover your second coil location is better for radiant heat than your original was. Or you may discover one of your coils absorbs and retains heat better than the other one. Really you still have too many variables, but getting closer.

And yes, your example is an excellent reason not to immediately believe every jack wagon on the internet that says "I did this thing and it worked!" without evidence that what worked was really what they thought it was, and not just dumb luck or a consequence of something completely unrelated.

Post #1 was not comparing the operating temp of Accel & Pert coils? What was it then?

It can't be, because he changed variables by mounting the coils in different locations when he took the temperatures. And he hasn't even begun to determine the operating temperature of either coil, because parking the coil next to a header tube is a bigger heat source than the internal resistance is. Realistically with how he took the measurements he's probably just found his under hood temperature at two different locations, since an IR gun just measures surface temperature and it's readings can be greatly effected by the actual surface it's pointed at.

If you want to actually compare the operating temperatures of the coils due to their difference in internal resistance, you'd have to eliminate all the external heat sources. Even if you just wanted to compare them head to head in the engine bay, you'd have to mount them in the same location to make a comparison. But even then you could be inadvertently testing whether a yellow coil or a black coil absorbs more radiant heat (or is read differently by IR!), or how a larger oil capacity effects heat/lag time.

And since we haven't even measured discharge voltage yet nothing that's been measured may mean a single thing with regard to how the coil actually functions

All reasons why anecdotal evidence isn't worth a hill of beans! Which was the actual point of post #1. If you read that post and didn't realize he never made a like to like comparison then you made his point for him.