Topic: Using a dwell meter and a timing question...

[Jonesy]

Hello, all-

I recently obtained a dwell meter and I've read in many places it is a must for optimum ignition performance. Unfortunately, it came with no instructions. Can anyone explain or direct me to a website that outlines how to use it when tuning the ignition on an SOHC/4?

This leads me into the second question about setting timing. When I gap the points to the manual specs, I can't get enough rotation of the breaker plate in order to get the timing marks to line up. I end up having to adjust the points themselves to get the marks lining up. I've double checked and I seem to be doing everything "by the book", so I'm puzzled if I'm missing something or maybe there is an aftermarket breaker plate on there that does not have the correct slots for adjustment...?

Thanks in advance!

[Bob Wessner]

I can't address your dwell meter question, but even when setting points statically, I have also found that moving the plates only does not do the trick, particularly if you had set the gap to the min. range suggested. I found you had to adjust the gap to alter the timing as well. As I recall, wider gap = advance, narrower gap = retard. As long as the gap remains within the limits, I think you are fine. Mine seemed to like .015.

[eldar]

You have to set the points to the correct gap first, then use the plate as a fine tune. I have never run out of room on moving the plates. It is hard to describe with out being able to show a person. But I will say I eyeballed my timing, I used NO gauges or meters or anything like that. I hooked up my timing light and my 1-4 were dead on even on advance and 2-3 were barely off and adjustment made almost no difference. A dwell meter probably makes the process easier but is hardly required.

[Harry]

Regarding the gap, there is a point (oooh, sorry) in the FAQ regarding this:

http://www.sohc4.us/forums/index.php?topic=261.0

[Jonesy]

OK, these have answered my question about the points plate adjustment, but what about the dwell meter? I know how to hook mine up, but what it the readout telling me?

[Warlock]

Greets,

Cam angle, or dwell angle, is the number of degrees of cam rotation during which the contact points remain closed. It is during this period that the current in the primary coil winding increases. Although dwell angle may not change, the length of time that the contacts remain closed diminishes as the engine speed increases. At higher engine speeds, the coil primary current does not reach it's maximum value due to self-inductance in the short length of time the contacts are closed. To store the maximum amount of energy in the coil and obtain sufficient energy to fire the plug, the breaker assembly must operate properly at higher speeds (i.e. correct dwell angle).

The point opening is the maximum distance that occurs between the contacts as the cam rotates. If the dwell is properly set, the point opening most likely will be within specifications. Ideally, point gap and dwell angle should both be checked to insure that the contacts are properly set. Feeler gauges can be used on new point sets or used points when a point file has been used to dress the contact surfaces flat. Otherwise, a dial indicator is recommended for checking used point gaps. If the point gap is not within specs with the dwell properly set, the contact point rubbing block and/or the cam lobe(s) are most likely worn...