Switching a DC voltage , unlike a AC voltage even at the low current rates that coils run at makes for pitting which just compounds the local heat at the contact point!
If your wall light switches in your home had to switch DC and not AC they would not last the average 20 years, they would last maybe 3 years before intermitants drove you nuts!
Vented points do run cooler , but there smaller surface area limits how long they will last, at best I say it's crap shoot!
Some unvented points have much bigger arms there are welded to and that greatly helps in heat sinking the contacts, but with vented points your still left with having more current flowing thru less area which to me = less life.
It's the same thing as running current level thru a 18 gauge wire that call for a 16 gauge.
The one thing in all of this that is for sure is once points get pitted, or even worse yet you file them the dwell you read on a meter is not really what the motor see's if you ask me!
I have never had a set of points that I have filed up that allow a motor to idle as good as a new set of points that's for sure, no matter how careful I filed them!
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!
1) 1940s 100% silver 4 cup tea server set.
Two dry rotted 14 x 10 Micky Thompson slicks.
1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.
Education is what your left with once you forget things!
Last edited by steve25; 05-05-2017 at 11:47 AM.
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