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| | | | Joined: Jul 2009 Posts: 367 'Bolter | | 'Bolter Joined: Jul 2009 Posts: 367 | I put a new distributor in my truck last nite and set the points at .016. When it was running the dwell shows 24 deg. I think the spec is 32 deg. Should I close or open the gap to get this. Or just go with .016. | | | | | Joined: Apr 2005 Posts: 7,440 Bolter | | Bolter Joined: Apr 2005 Posts: 7,440 | I personally think you are right on. Just drive it. 
Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
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| | | | | Joined: Apr 2005 Posts: 2,832 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 2,832 | I pretty much believe in what instruments tell me so the dwell is low. If you are going to just do light cruising your fine but if you are going to be raising the rpm up then you're not going to get enough coil saturation time for a consistent spark. A bit surprised it's a new unit as low dwell with a feeler gauge setting is often from a worn cam or shaft/bushings. As Martin said, try it and if you get high speed flutter you will know the problem.
Evan
| | | | | Joined: Feb 2004 Posts: 29,742 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,742 | Close up the gap just a little. "Dwell" indicates the number of degrees of distributor rotation the points "dwell together"- - - -points closed, to make it simple. A 6-lobe distributor cam has 60 degrees between high spots, and the points need to stay closed approximately 2/3 of the time, so 40 degrees would be the maximum points closed time. Early stovebolt distributors ran 37-38 or more, while later models dropped the dwell down to the low 30's for some reason.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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| | | | | Joined: Jul 2009 Posts: 367 'Bolter | | 'Bolter Joined: Jul 2009 Posts: 367 | Thanks, I will close it up this eve and hope to make a speed run in the morn. I wondered about point bounce but don't think this engine will turn enough to get it. | | | | | Joined: Jan 2016 Posts: 631 'Bolter | | 'Bolter Joined: Jan 2016 Posts: 631 | Close up the gap just a little. "Dwell" indicates the number of degrees of distributor rotation the points "dwell together"- - - -points closed, to make it simple. A 6-lobe distributor cam has 60 degrees between high spots, and the points need to stay closed approximately 2/3 of the time, so 40 degrees would be the maximum points closed time. Early stovebolt distributors ran 37-38 or more, while later models dropped the dwell down to the low 30's for some reason.
Jerry Think the change was the cam profile changed as per DEVE HEI upgrade how to ID early from late distributors. http://devestechnet.com/Home/HEIgnition
Last edited by showkey; 07/22/2016 7:11 PM.
| | | | | Joined: Jul 2009 Posts: 367 'Bolter | | 'Bolter Joined: Jul 2009 Posts: 367 | I got it to 31 deg now and am going to road test later(weather permiting) Thanks for all the help | | | | | Joined: Feb 2004 Posts: 29,742 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,742 | I believe you'll find the dwell reduction actually happened with the conversion to 12 volts. The higher voltage allowed for better coil magnetic saturation and more "points open" time for point cooling. No sense going off on some theoretical flight of fantasy when there's a logical explanation for something.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | Sometimes a feeler gauge is not held flat and will cause a larger gap than you think it is. As Jerry said smaller gap= larger dwell. Go by what meter says. That's why Chevy had the window on the dizzys. I love that for setting points to a meter.
Also I assume you have new points. New points MUST be examined and tweaked so that the contact pads are concentric and flat to each other. You do this by "bending/twisting" the fixed contact side of the points. NOT the lever side. Many points are cheaply made and, if not aligned, (calibrated) will be hard to set and give bad performance. The flat spring must also be spot on, not too strong, not too weak.
Bottom line is ALWAYS, how does she start and how does she run? Don't mess with mother nature.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
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