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It's been a couple of decades since I last set the dwell. Need to adjust mine a degree or two. Was expecting to adjust with an Allen wrench behind the window, but found this instead (see photo). Can someone tell me what kind of ignition system I have and how to adjust the dwell?
The allen wrench window was the best invention by GM since the winged front windows on early sedans.
The complaint of not reaching the GM dizzy easily was one of Fords front dizzy best feature.
Looks like somebody got tired of playing with points, condenser, dwell and took the fun / work out of yours and went more modern, reliable.
So, your concern for your surprise finding is "pointless". (pun intended)
Can't say I have ever seen studs to mount the rotor though.
From: At my Bar drinking and wrenching in Lafayette Colorado
That's a cheap aftermarket electronic ignition conversion, so you can't set the dwell. If your car were in my shop, I would remove that conversion kit and throw it down the driveway. Then, I'd install a good quality set of points with condenser and bring the car back to a stock, reliable configuration
Lars.
Not wanting to "dwell" on the subject but his first sentence says two decades . . . .
Can't be too bad of a replacement unit to get 20 yrs out of 'er. But still.
Aldo J,
What has triggered you to suspect the dwell has changed? Timing marks moving?
I probably hedged a bit with 'a couple of decades '. More like four decades ago. The more I work on this car, the more I realize the (or a) previous owner knew less than me. Ugh!
Thank you for sharing your insights. Will surely heed your advice.
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by HeadsU.P.
Not wanting to "dwell" on the subject but his first sentence says two decades . . . .Can't be too bad of a replacement unit to get 20 yrs out of 'er.
Tough to argue your "point."
Obviously, if reliability has not been an issue, Aldo's option is to simply leave well enough alone. On that track, there is no dwell to set, so proceed with timing setup.
The reason he is wanting to set the dwell is that he is working on setting up his timing per my timing instructions. The first step, if you have a points-type distributor, is to check and set dwell, since each degree change in dwell changes the timing by one degree. With the elctronic conversion, he can skip the "set dwell" step before setting timing.
Lars
Not wanting to "dwell" on the subject but his first sentence says two decades . . . .
Can't be too bad of a replacement unit to get 20 yrs out of 'er. But still.
Aldo J,
What has triggered you to suspect the dwell has changed? Timing marks moving?
Lars rebuilt a carb and I'm following his advice to 'tune for peak performance.' Using a dwell/tach, the dwell is reading 33 when factory specs call for 30. Figured a turn or two of the Allen wrench and I'd be good. Nope!
Tough to argue your "point."
Obviously, if reliability has not been an issue, Aldo's option is to simply leave well enough alone. On that track, there is no dwell to set, so proceed with timing setup.
The reason he is wanting to set the dwell is that he is working on setting up his timing per my timing instructions. The first step, if you have a points-type distributor, is to check and set dwell, since each degree change in dwell changes the timing by one degree. With the elctronic conversion, he can skip the "set dwell" step before setting timing.
Lars
From: At my Bar drinking and wrenching in Lafayette Colorado
Or, if you want to convert back to points, simply stop by your local NAPA store and pick up a set of the high performance CS786 points with the RR175 condenser and a new LW72 primary lead wire.
Lars
Or, if you want to convert back to points, simply stop by your local NAPA store and pick up a set of the high performance CS786 points with the RR175 condenser and a new LW72 primary lead wire.
Lars
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by HeadsU.P.
The allen wrench window was the best invention by GM since the winged front windows on early sedans.
The complaint of not reaching the GM dizzy easily was one of Fords front dizzy best feature.
Looks like somebody got tired of playing with points, condenser, dwell and took the fun / work out of yours and went more modern, reliable.
So, your concern for your surprise finding is "pointless". (pun intended)
Can't say I have ever seen studs to mount the rotor though.
I suspect the previous owner noticed (or read in the ignition module directions) that the rotor screws may possibly hang down too low and hit the upper part of the module assembly. I had a somewhat similar issue with my conversion to a variable reluctance pickup coil in my distributor. Got several decades of reliable service, but had to replace a bad rotor a few years back. The captured screws on the new rotor were about a sixteenth or 3/32" longer (which I didn't notice), and they hit the pickup coil as the distributor was turning. Pulled the cap off and saw the issue. Pure dumb luck that the pickup wasn't damaged. I swapped out the screws to a shorter pair, and I was back in business.
Setting Dwell
