Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/)
-   Porsche 911 Technical Forum (http://forums.pelicanparts.com/porsche-911-technical-forum/)
-   -   If points gap is correct, should dwell also be? (http://forums.pelicanparts.com/porsche-911-technical-forum/592448-if-points-gap-correct-should-dwell-also.html)

jwakil 02-18-2011 06:17 AM

If points gap is correct, should dwell also be?
 
I'm trying to adjust my distributor with points. If I get the gap correct, does that imply that the dwell angle should be fine? I'm trying to decide if I need a separate dwell meter.

HarryD 02-18-2011 06:24 AM

If you get the gap correct, the dwell "should" be within range. The dwell meter will serve to fine tune the setting.

Superman 02-18-2011 07:02 AM

Harry is correct. However, no matter how close you think the gap is, the dwell angle will almost certainly be incorrect. A dwell meter will tell you how close you got it when you set the point gap. Also.....dwell meters can be had for peanuts. Thrift stores, pawn shops, garage sales, etc. Better yet, do yourself a big favor and upgrade to an electronic ignition trigger.

Bill Verburg 02-18-2011 07:04 AM

Quote:

Originally Posted by jwakil (Post 5853980)
I'm trying to adjust my distributor with points. If I get the gap correct, does that imply that the dwell angle should be fine? I'm trying to decide if I need a separate dwell meter.

point gap determines dwell, the wider the gap the lower the dwell.

The more precise measure is dwell.

Set the gap w/ feelers then zero it in w/ dwell.

since the primary issue w/ points as implemented in a Porsche CDI system is rubbing block wear and the resulting decrease in point gap over time, it's best to set up the gap on the high side, which is on the low side for a dwell measurement

911pcars 02-18-2011 12:30 PM

Quote:

Originally Posted by Bill Verburg (Post 5854068)
point gap determines dwell, the wider the gap the lower the dwell.

The more precise measure is dwell.

Set the gap w/ feelers then zero it in w/ dwell.

since the primary issue w/ points as implemented in a Porsche CDI system is rubbing block wear and the resulting decrease in point gap over time, it's best to set up the gap on the high side, which is on the low side for a dwell measurement

To add to Bill's response: Every 1 degree of dwell change also changes the ignition timing by the same amount. Thus, as the rubbing block wears, the point gap becomes smaller and the ignition retards (e.g. 5ºBTDC > 4ºBTDC).

Sherwood

rattlsnak 02-18-2011 07:01 PM

yes, and dwell affects timing, but timing does not affect dwell...

dan88911 02-19-2011 10:28 PM

Quote:

Originally Posted by Superman (Post 5854067)
Harry is correct. However, no matter how close you think the gap is, the dwell angle will almost certainly be incorrect. A dwell meter will tell you how close you got it when you set the point gap. Also.....dwell meters can be had for peanuts. Thrift stores, pawn shops, garage sales, etc. Better yet, do yourself a big favor and upgrade to an electronic ignition trigger.

Don't mean to high jack. However, what is this electronic ignition trigger you speak of ? :)

HarryD 02-20-2011 10:50 AM

Quote:

Originally Posted by dan88911 (Post 5857225)
Don't mean to high jack. However, what is this electronic ignition trigger you speak of ? :)

Good question. I presume we mean someting like Pertronix (Pelican Parts.com - Pertronix Ignitor) or other electrical item to replace the points with an electronic triggering device.

dan88911 02-20-2011 05:29 PM

Thanks HarryD. I remember something like this in the 70's for muscle cars.

Joe Bob 02-20-2011 10:15 PM

Pertronix while a good idea, are failure prone, hence the recommendation to carry points with you on the road.....


All times are GMT -8. The time now is 05:53 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.