The Stovebolt Site Forums The Shop Area Engine Shop What is "dwell"

Is it the duration between the time the points open until they are closed again? How is it set and what should it be set at on a 350?

Other way around, it's the time in camshaft degrees that the points are closed to saturate the coil. According to the manual, it's 28-32, you will need a dwellmeter to set it correctly. You can set the point gap at .019" as a starting point.

In the earlier years the distributors had a little metal door on them that you could raise up and put in a small allen wrench and turn it until the dwell reading was what you wanted. Back then I think it was around 18-22 but my memory is foggy that far back. Back then most folks had a "RPM/Dwell meter combination. Later years I can't speak to. I don't remember what year it was that everything went to electronic ignition.

Bill is exactly right and if your 350 has a points type distributer it should have the point access window. With this type distributer you can set the dwell with the engine running. On ford and chrysler (and others) you can hook your leads up and set the point dwell with a screwdriver while spinning the engine over with the starter. Closing increases dwell. opening decreases.

Hy guys, just a tip, always set your dwell first, dwell affects timing, but timing does not affect dwell. One degree of dwell affects timing by one degree, hope that helps.

Does anybody knowwhy they didn't have that adjustment screw on the outside of the distributors for the 6 cylinders? Did they think that the people who bought the trucks with the 6 cylinder engines wouldn't mind having to take of the cap, adjust the dwell, put the cap back on, check the dwell, take the cap back off, re-adjust the dwell, etc. It was a big enough PIA for me to install a Pertronix electronic ignition conversion kit.

I don't know why 6 cyl. engines didn't have a dwell door.
If you have a door on your cap, when the dwell is properly set and the timing properly adjusted. The next time you replace your points, and you adjust your dwell (running) you won't have to reset your timing. (check it anyway)

If you set the point gap right the dwell will fall in specs.

Thanks for all the good info. I have never checked the dwell in the past, mainly because I didn't know anything about it. I would always set the point gap at .019 and if the engine ran good, it was good enough for me. Figured there was no need in overcomplicating the situation.

just an FYI......
if some of you have an HEI dist
you don't have dwell.

since you mentioned a 350, it may have a more modern dist.

Actually, an HEI has dwell, it's operated electronicly, as opposed to the opening and closing of mechanical points.

A while back I took a coil from my 81 Dodge Colt and put it on my 62, 235. It seems to run OK but it sure could use more power. I was wondering if that coil could be causing me problems.

No, it's probably the fact that it's a 235 I'm afraid. They run good but don't make a lot of power.

Yeah, I gave up on points too. Pertronix just makes it so easy for very little money.

6 cyl's. don't have an outside adjustment for dwell, probably because the distributor is smaller than the v-thing, and the points for adjustable dwell are pretty bulky and probably wouldn't fit inside the 6 cyl. distributor.

When I still had points, I would set the gap, then check the dwell. I was of the opinion that what really counted in terms of the coil discharge was the dwell angle; the point gap was just a means of estimating what the dwell was based on the shape of the distributor shift and the distance between the the points. The larger the distance, the greater the angle traveled by the distributor shaft before the points close. While the point gap should be an accurate indication of the dwell angle, it isn't exactly the same thing. Therefore, I felt that it was more accurate to measure the actual dwell angle after setting the point gap to get it in the ballpark (within a few degrees).

Thanks for the explanation of why the 6 cylinder distributor doesn't have an exterior means of adjusting the points. I've never seen one of the V8 distributors, but what you say makes sense.