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> Petronics Ignition question, Dwell percentage
ILM914
post Sep 24 2011, 10:56 AM
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Hello everyone I installed a Petronics Elec ignition. Car runs good and I timed it OK with a strobe light; but when I check the Dwell (percent value) it reads 69% while my Haynes Manual says it should read 49-55%. I tried changed the gap between the magnet and the module but it made no difference. Is it ok to leave it at the 69% setting? Thanks, Joe
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TheCabinetmaker
post Sep 24 2011, 11:19 AM
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You don't have points any more. Therefore, you have no dwell either. Set the gap with the feeler gauge provided and forget it. easy as that.
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Drums66
post Sep 24 2011, 11:27 AM
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......Ya dig, it is a set it & forget it type situation...cool drive on! (IMG:style_emoticons/default/driving.gif)
excellent choice (IMG:style_emoticons/default/idea.gif) (IMG:style_emoticons/default/bye1.gif) (IMG:style_emoticons/default/yellowsleep[1].gif) (IMG:style_emoticons/default/yellowsleep[1].gif) (IMG:style_emoticons/default/popcorn[1].gif)
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type47
post Sep 24 2011, 03:03 PM
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When you change from points to pertronix, will the timing change with the pertronix compared to the timing with points? Another way, do you have to reset the timing with a strobe light when a pertronix is installed. If the timing is set within spec does installing Pertronix change the timing?
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Dave_Darling
post Sep 24 2011, 03:43 PM
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Yes, the timing may change. At the very least, you need to re-check the timing.

--DD
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messix
post Sep 24 2011, 04:59 PM
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it can get away with a longer dwell time because it is an electronic circuit and not a mechanical switch [the points], the points are not as precise as the electronic module over the rpm range thats why the increase in dwell
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Spoke
post Sep 24 2011, 07:52 PM
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The reason for dwell is to give the coil time to build up energy. The Pertronix takes dwell out of the equation. Time it and drive it like you stole it.

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ILM914
post Oct 5 2011, 05:31 PM
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Thank you very much I appreciate the resonse, Joe


QUOTE(vsg914 @ Sep 24 2011, 09:19 AM) *

You don't have points any more. Therefore, you have no dwell either. Set the gap with the feeler gauge provided and forget it. easy as that.

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Cap'n Krusty
post Oct 5 2011, 06:54 PM
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QUOTE(ILM914 @ Sep 24 2011, 09:56 AM) *

Hello everyone I installed a Petronics Elec ignition. Car runs good and I timed it OK with a strobe light; but when I check the Dwell (percent value) it reads 69% while my Haynes Manual says it should read 49-55%. I tried changed the gap between the magnet and the module but it made no difference. Is it ok to leave it at the 69% setting? Thanks, Joe



The dwell is fine. The figure quoted in Haynes is for points. It's wrong, but it's for points. The real number is 47 degrees +/- 2 degrees.

The Cap'n
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ILM914
post Oct 10 2011, 08:19 PM
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Thank you everone, much appreciated. I am happy, rebuilt Dizzy works great. car is running awesome, nice low rev power.
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