Distributor Replacement
Team Owner
Joined: Oct 2000
Posts: 38,897
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From: Washington Michigan
The link below will take you to a "Timing 101" article that explains ignition timing and advance systems:
http://www.camaros.org/pdf/timing101.pdf
Thread Starter
Instructor
Joined: Jul 2014
Posts: 135
Likes: 17
From: Punta Gorda, Florida
Bad assumption. The correct VAC will make a big difference in idle cooling, throttle response, and fuel economy; it will add 15* of advance at idle over and above your base timing setting. What's your manifold vacuum now at idle? That's what determines which vacuum advance can you need (auto parts stores don't have a clue - they don't even know what they do).
The link below will take you to a "Timing 101" article that explains ignition timing and advance systems:
http://www.camaros.org/pdf/timing101.pdf
The link below will take you to a "Timing 101" article that explains ignition timing and advance systems:
http://www.camaros.org/pdf/timing101.pdf
Now I'm wondering about trying to repair the distributor. Lars seems to get a lot of favorable endorsements for setting one up. How do I get in touch with Lars?
Maybe I should just go with a new Pertronix distributor? This car is a driver, not a NCRS car.
Thanks again for your valued input.
Team Owner
Joined: Sep 2002
Posts: 38,323
Likes: 2,071
From: California
Funny
How some send their distributors back to this Lars guy and it comes back recurved each time! Point One- if it was getting that messed up, then it tells me the operator doesn't have a clue as to maintaining the unit and lets it completely get to a state of disaster, needing an overhaul! Not good sounding! Especially on the tune, if it was needing such as a recurve!
Also don't see how a car can be tuned to perfection, if the unit is traveling back and forth UPS!
Also don't see how a car can be tuned to perfection, if the unit is traveling back and forth UPS!
Team Owner
Joined: Sep 2002
Posts: 38,323
Likes: 2,071
From: California
Hi
OK, I'm slowly working my way through issues/questions on my car, new to me last summer. I was thinking about upgrading the distributor to electronic to eliminate the points. Although I haven't had a problem yet, I remember from my youth the points were problematic. I replaced the stock distributor on my 1968 Z28 with a Mallory dual point distributor to eliminate point bounce at higher RPM. Since the Corvette engine I have has a much lower redline it may not be a problem, but the upgrade on the distributor eliminated point problems.
Any thoughts on replacing the points with an electronic module, or replacing the entire distributor? The current distributor has had the vacuum advance can removed.
TIA, Gene
Any thoughts on replacing the points with an electronic module, or replacing the entire distributor? The current distributor has had the vacuum advance can removed.
TIA, Gene
Therefore I don't think converting a ""dual point unit"" would be a good idea!
On a lower HP car, where you are wanting the broadest range in rpm operation, it would be good to return to vacuum advance, because the non vacuum units are usually set up to hit in a certain rpm range, all in and suddenly like in Poker! Tuning your advance weights can improve that, but that is the area of true experts with distributor machines! No one with stock components or pertronix type setups with vacuum advance should actually need an expert! If you continued to run dual point and no vacuum, then a guy like a Lars would be worth the investment!
Last edited by TCracingCA; May 19, 2015 at 03:15 AM. Reason: ADDED ((by increased dwell))
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
How some send their distributors back to this Lars guy and it comes back recurved each time! Point One- if it was getting that messed up, then it tells me the operator doesn't have a clue as to maintaining the unit and lets it completely get to a state of disaster, needing an overhaul! Not good sounding! Especially on the tune, if it was needing such as a recurve!
Also don't see how a car can be tuned to perfection, if the unit is traveling back and forth UPS!
Also don't see how a car can be tuned to perfection, if the unit is traveling back and forth UPS!
Team Owner
Joined: Sep 2002
Posts: 38,323
Likes: 2,071
From: California
Yes and the rest don't need a renowed expert!
You're amazingly perceptive. In your deliberations, you might consider that possibly 3 out of ten owners even knows what the inside of the distributor looks like, two out of ten might know how it actually works, and maybe one out of ten has the tools and knowledge to disassemble and rebuild one. That leaves about seven out of ten who need the services of guys like Lars, DZAUTO, and John (Plasticman) for distributor maintenance, rebuild, and setup. The distributor is the least-maintained part on the car, because most people are afraid to touch them.
Yes you are very perceptive also!
So i would recommend Lars, DZAuto, and Plasticman for the special stuff, but naturally these individuals are also way more highly qualified for this type of basic and really simple routine work also!
Last edited by TCracingCA; May 18, 2015 at 03:06 PM.
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Team Owner
Joined: Oct 2000
Posts: 38,897
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From: Washington Michigan
A dual point is a higher performance unit! What you have is two sets of points usually, that are set to fire at slightly differing times so the first creates a firing first and starts the ignition of your fuel, and then the second fires off to promote the burn or duration of the burn.
Team Owner
Joined: Sep 2002
Posts: 38,323
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From: California
True i was trying to give a simple explaination!!
But us experts know that the spark comes out of each wire. spark technically wasn't the right choice of word, i should have said """point firing to be correct to your standard of vocabulary! But i think the original post would explain things sufficiently enough to a person, not knowing much about what we are talking about. Therefore your keeping it all honest to the technical is a valid and worthy addition!
Yes single spark of longer length, generated by a dual point firing! Do you feel better now! But some and alot can classify the firing of a point set as a spark. it is a version of jumping from contact to contact that differs from other spark transmission where a spark plug gap is jumped! and location where current is passed, can be essentially classified as a spark! PS when the points get burned, a spark, a sizzle, or conduction of electrical or whatever you want to call it, usually causes that! Therefore the gap is important to shut that conduction down.
How far would you like to go with this?
Yes single spark of longer length, generated by a dual point firing! Do you feel better now! But some and alot can classify the firing of a point set as a spark. it is a version of jumping from contact to contact that differs from other spark transmission where a spark plug gap is jumped! and location where current is passed, can be essentially classified as a spark! PS when the points get burned, a spark, a sizzle, or conduction of electrical or whatever you want to call it, usually causes that! Therefore the gap is important to shut that conduction down.
How far would you like to go with this?
Last edited by TCracingCA; May 19, 2015 at 08:56 PM.
Safety Car
Joined: May 2003
Posts: 4,797
Likes: 239
From: Ocean Township NJ
In a dual points setup, the two sets of points are wired in parallel. This however does nothing to eliminate points bounce and spark scatter at higher RPM, as well as eliminate wear issues associated with electormechanical devices. A Hall Effect trigger, like M & H (Breakerless SE, which will only work with a stock primary feed), or a Mallory, Pertronix, Accel, MSD will eliminate all dwell related voltage variations as well as typical electromechanical wear/maintenance issues.
Team Owner
Joined: Sep 2002
Posts: 38,323
Likes: 2,071
From: California
You are one of the very knowledge guys, but watch it in using the word spark
In a dual points setup, the two sets of points are wired in parallel. This however does nothing to eliminate points bounce and spark scatter at higher RPM, as well as eliminate wear issues associated with electormechanical devices. A Hall Effect trigger, like M & H (Breakerless SE, which will only work with a stock primary feed), or a Mallory, Pertronix, Accel, MSD will eliminate all dwell related voltage problems as well as typical electromechanical wear/maintenance issues.
Last edited by TCracingCA; May 19, 2015 at 01:17 AM.
Team Owner
Joined: Mar 2003
Posts: 26,118
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From: Greenville, Indiana
Scroll down to figure 12 as to how dual points work in a Chevy OEM distributor.
http://randysrepairshop.net/basic-ig...-it-works.html
For the newbs, this is a pretty good description how points work.
http://randysrepairshop.net/basic-ig...-it-works.html
For the newbs, this is a pretty good description how points work.
Team Owner
Joined: Sep 2002
Posts: 38,323
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From: California
We should reference your post prior to any help to anyone wanting help
Scroll down to figure 12 as to how dual points work in a Chevy OEM distributor.
http://randysrepairshop.net/basic-ig...-it-works.html
For the newbs, this is a pretty good description how points work.
http://randysrepairshop.net/basic-ig...-it-works.html
For the newbs, this is a pretty good description how points work.
Since we were turned to travel down that rode for the exact technical, this was a very wise post (MikeM)!!!!!
I was just bothered that all of the experts came on and didn't think to address the OP's dual point unit! Started down a road of pertronix recommendations and such! Wow! Scary!
And PS-- if this """dual point""" would have actually ended up in the hands of Lars, I know he would have straightened it all out prior to it going down the wrong path!
Last edited by TCracingCA; May 18, 2015 at 04:00 PM.
Racer
Joined: Dec 2014
Posts: 267
Likes: 6
From: Dickinson Texas
OK, I'm slowly working my way through issues/questions on my car, new to me last summer. I was thinking about upgrading the distributor to electronic to eliminate the points. Although I haven't had a problem yet, I remember from my youth the points were problematic. I replaced the stock distributor on my 1968 Z28 with a Mallory dual point distributor to eliminate point bounce at higher RPM. Since the Corvette engine I have has a much lower redline it may not be a problem, but the upgrade on the distributor eliminated point problems.
Any thoughts on replacing the points with an electronic module, or replacing the entire distributor? The current distributor has had the vacuum advance can removed.
TIA, Gene
Any thoughts on replacing the points with an electronic module, or replacing the entire distributor? The current distributor has had the vacuum advance can removed.
TIA, Gene
Exactly what is the "upgrade on the distributor" that you speak of here (bolded above)? Did you add dual points? Did the dizzy come with dual points already installed?
If you DO have dual points, I don't think that you can install a vacuum advance diaphragm. Somebody correct me if I'm wrong, but aren't dual points and vacuum advance mutually exclusive?
From what you've posted, I don't believe that you need a new dizzy. The ones with tach drives are pretty costly too!
Yogi
Team Owner
Joined: Mar 2003
Posts: 26,118
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From: Greenville, Indiana
Melting Slicks
Joined: Apr 2006
Posts: 2,331
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From: Sunnyvale CA
I know you said NOT an show car, but do you want to maintain a fairly stock look, with the distributor and plug wiring under the metal shielding? That influences your options.
Unless you have a really high-revving, non-stock engine, why are you worried about point bounce? And if you are, my (very limited
) understanding is that point bounce would be addressed by heavy-duty, racing-type points that are sprung maybe twice as stiffly as stock points, (Probably wear the out the rubbing block faster?) If your engine is pretty much stock, and the factory didn't build it with dual points, I don't think dual points are going to do anything for you. I think, as others are saying, what you need is a stock Delco distributor with the proper vacuum advance can, set up by someone who is knowledgeable and experienced with such things. Either with stock-type single points or any of the various breakerless conversions, including Pertronix. Probably best to get it back to stock and work with points first. When you have it working well, you may then lose interest in the breakerless conversion. Or not.Just my two percent of a dollar.
Steve
Team Owner
Joined: Sep 2002
Posts: 38,323
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From: California
Also since no one thought to address the specific unit you own!
I bet if we cross referenced it or looked it up, it probably is a dedicated built without vacuum advance dual point unit! I don't know mallory offerings, but it would be nice to figure out if mallory makes an adaptable vacuum advance kit for this unit! And also actually a dual point can actually be set up to run a mild tune engine.
Melting Slicks
Joined: Apr 2006
Posts: 2,331
Likes: 61
From: Sunnyvale CA
I bet if we cross referenced it or looked it up, it probably is a dedicated built without vacuum advance dual point unit! I don't know mallory offerings, but it would be nice to figure out if mallory makes an adaptable vacuum advance kit for this unit! And also actually a dual point can actually be set up to run a mild tune engine.
Steve
Last edited by SI67; May 19, 2015 at 12:05 PM.
Team Owner
Joined: Sep 2002
Posts: 38,323
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From: California
We are all trying to help him!
Derek, based on a reread of the original post, I don't think Gene is trying to figure out what to do about a Mallory dual point. THAT was what he put in his 68 Z28. I think he's trying to figure out to do about the distributor in his mild 64 Corvette, and all we here know about the distributor is that IT doesn't have a vacuum advance unit. I don't think said the dizzy in the Vette is a Mallory, or that it's a dual-point unit, so whatever it is, it's probably a single-point unit. Maybe even the original Delco, stripped of its vac advance unit. Original Poster Gene, if my attempt at clarification is all wrong, please jump in and shut me up!
Steve
Steve