Good distributor options

[Don W.]

Re: Good distributor options

Thanks Dave! I, for one, will try a wider gap next time the plugs are out even though currently I have no issues.

MSD still recommends drilling the cap AND sinking (sp?) the rotor with the cap. The reason for my weird rotor posted earlier.

 

[Davemc1963]

Re: Good distributor options

I read most of it too. Great info as usual DaveP. Unusual mix of imperial and SI units in the observations. Good food for thought though and to me raises other questions. The voltage required to fire the plugs changing based on the temperature of the plug electrode was interesting. It would be interesting to actually know if the plugs we run are in fact the optimum heat range for some of our 'modified set ups' and if the iridium fine wire plugs offer any advantages here. Old school theory I was taught was to run a colder plug if you upped the compression and or timing, to help avoid pre-ignition, but only if they didn't foul up while driving around town. Various types of plugs are available to help with that such as projected nose types, but not all lend themselves to forced induction (allegedly) I would guess that different (colder) plugs could eleviate some knock issues some have. A different subject for a another post though. Thanks for making me think about it though.

 

[Windedv6]

Re: Good distributor options

I have run the MSD billet distributors for years with only one problem and that was a good 10-15 years ago. MSD replaced it. Have not had any issues with them since. I have keep a spare on the shelf in case there is a problem. Maybe thats the trick. Buy a spare and you will never need to use it!

I disagree with the theory on plug gapping. I run Digital 7 boxes on my trucks which works much better on high cylinder pressured (boosted) motors than the 6al boxes. A good comprise is the Digital 6 box. I have spent a lot of time with different plugs and gap. Different compressions, different boost, different head materials, different chamber designs, different piston designs, different valve timing, different ignition timing, different intake/runner design, different fuel etc, all can contribute to how a flame will light off. Like most motors you need to give it what it likes. My motors are a lot happier gapped at .028 with an NGK 7 plug.

The correct answer (as stated in DaveP's comments) is "there is either enough power to charge the gap or there isn't". Under high cylinder pressures and heavy fuel, the charge may not complete or may be weakened. Its not feasible to run magnetos so we run cheaper oem style ignitions designed to keep manufactoring costs down. Shortening the plug gap can allow a weaker than required charge to complete the process.

When I went to an MSD 7 series box I could open up my gap wider than my previous 6 series box. It does require more energy at the plug the higher the cylinder pressure becomes. Don't confuse cylinder pressure with boost. Just because someone is running 20-25 lbs boost on a small turbo and small flow heads doesn't mean he has the same cylinder conditions as the guy running 20-25 lbs boost with a bigger turbo and higher flowing heads. For the majority of us SYTY V6 owners, max cylinder pressure is going to be more linear to our hp as most of us are running about the same 8.5:1 compression ratio setups. So, yes a .035 gap will be fine for many of us depending on our ignition setup and hp. For those with higher hp builds and depending on your ignition setup you may be needing to close your gaps a little.

 

[cloneman315]

Re: Good distributor options

I have used the autozone on trucks with good luck. I have also used MSD on many things with no issues ever. And I run my gaps tight around under .20

 

[Windedv6]

Re: Good distributor options

Thanks Dave! I, for one, will try a wider gap next time the plugs are out even though currently I have no issues.

MSD still recommends drilling the cap AND sinking (sp?) the rotor with the cap. The reason for my weird rotor posted earlier.

One of our issues with our small cap distributors is that when we go higher in boost we retard the timing accordingly. When the timing retards the rotor to cap phase changes. simply put, the rotor and the corresponding cap pin gets farther apart, requiring a longer gap and produces more heat. This longer gap also causes requires more voltage which at some point starts to scatter voltage/spark into other areas of the cap. On the small cap v6 distributors with fixed rotors there is not a good way to correct the phase. I use a big case V8 style distributor and crank trigger on my higher rpm TT motor. I can phase the rotor to match the corresponding cap pin without changing the given timing. I phase the rotor to align the rotor and the pin at the timing point (23* on my motor setup) where the motor produces the most torque. This gives the ignition system that shortest and strongest path to he plug. At idle (35*) I am misaligned by 12* but there is little effect on the ignition system as the plug firing requirement is much lower.

The flip side is our OEM style small cap distributors. We set them straight up aligned at our initial timing. Under boost we take out timing and change the distance between the rotor and cap pin. Higher Hp motors produce higher cylinder pressures which need higher energy ignitions. Higher boosted motors retard the timing even farther causing a bigger distance between the rotor and pin. This extra energy can cause spark scatter in our smaller caps. as well as heat issues.

One remedy is to drill holes in the cap on plane with rotor, which seems to help with the spark scatter. The more difficult remedy is to change the pickup relucter position in order to phase the rotor and cap to correspond with the timing at the highest boost level.

Keeping your cap pins and rotor tip clean will help to a degree. As soon as there is a slight amount of buildup on the cap pins we seem to have problems as voltage/energy will look for the least path of resistance and its not hard to find other contact points in our small diameter caps.

 

[Don W.]

Re: Good distributor options

One of our issues with our small cap distributors is that when we go higher in boost we retard the timing accordingly. When the timing retards the rotor to cap phase changes. simply put, the rotor and the corresponding cap pin gets farther apart.

Case in point, in case you missed it earlier. I've been running this homemade setup for some years now with no issues. You can see where the burnt area is primarily NOT at the end of the rotor. I will try to get a photo today verifying your point with a cutaway cap that I have. With the relucter centered there is quite a gap between the rotor and cap terminal.

http://www.syty.net/forums/showthread.php?t=94747&highlight=phase

 

[cloneman315]

Re: Good distributor options

Here we go...

Because my dyno testing has proven that it works better for me..Iridium's

 

[Don W.]

Re: Good distributor options

Found with a little searching:

Gap Spacing – With increases in gap comes an increase in “start up” voltage, but the “lock in” voltage remains relatively the same regardless of gap. Ex. fluorescent light – a 1′ long bulb or a 6′ long bulb use a very similar amount of voltage to keep the gases ionized but the larger bulb requires a substantially larger voltage (ballast/transfmr) to initiate the ionization.

Plus a couple of interesting reads.

http://aftermarket.federalmogul.com...ts/High Performance Quick Reference Chart.pdf

http://www.setyourtiming.com/faq.html

 

[DaveP]

Re: Good distributor options

Maybe .0001 gap would work even better then? At some point, there is going to be such a thing as "too tight" as not enough heat will be produced by the spark to cause ignition of the mixture.

I see people here with fast, proven combinations stating they run .028. Fine. But your "tight around under .20" is an outlier. No one here runs gaps that tight, so I question the decision-tree that resulted in that gap. And I assume you mean ".020 (twenty thousandth's) and not ".20" (200 thousandth's, about 3/16").

 

[cloneman315]

Re: Good distributor options

.020 correct. My build is one of the more proven and quicker builds out there.... I don't care honestly what you or anyone else thinks or writes about. It just plain works for me.

 

[TurboSBC]

Re: Good distributor options

Thank you, Dave P and the rest. Makes much more sense now.

 

[Don W.]

Re: Good distributor options

In reading about spark plugs, gaps, whatever I often come across the term " ionization." Never quite knowing what that meant I thought it would be germane to the conversation. So I looked it up.


A spark gap consists of an arrangement of two conducting electrodes separated by a gap usually filled with a gas such as air, designed to allow an electric spark to pass between the conductors. When the voltage difference between the conductors exceeds the gap's breakdown voltage, a spark forms, ionizing the gas and drastically reducing its electrical resistance. An electric current then flows until the path of ionized gas is broken or the current reduces below a minimum value called the "holding current". This usually happens when the voltage drops, but in some cases occurs when the heated gas rises, stretching out and then breaking the filament of ionized gas. Usually, the action of ionizing the gas is violent and disruptive, often leading to sound (ranging from a snap for a spark plug to thunder for a lightning discharge), light and heat.


If I still have you the voltage required to exceed the "breakdown" voltage is governed by something called Paschen's law which I also looked up. The simple version:


At higher pressures and gap lengths, the breakdown voltage is approximately proportional to the product of pressure and gap length, and the term Paschen's law is sometimes used to refer to this simpler relation.

IOW the higher the cylinder pressure and/or wider the gap the more voltage it takes.


If you think about this, the topic and opinions stated actually make more sense. IOW we now have the "why" a spark does what it does.


I worked up sweat doing this so I hope it helps.:rotf:

 

[TurboSBC]

Re: Good distributor options

Wow. I think I've learned more about ignition and how it works in this post than I have in the previous 15 years.

Thanks. I really appreciate the time and effort put into these very informative posts.

 

[Owned]

Re: Good distributor options

Ok, back to original question. Did some homework and see what everyone recommends. Let me point out I'm on the west cost! Someone said Napa had an lifetime warranty which they don't here. GMC=discontinued go figure lol Chevy dealer had ac delco for $221. 3 month or 12,000 mile warranty, interesting part Is parts said if service is to install they would give an limited lifetime warranty lol and which labor cost is not included.limited also meant the unit would have to be unrepairable before free replacement. I actually like AC Delco as a brand but pricey. And now pep boys, autozone, same average price for remained Cardon brand, sorry for spelling. Roughly $99 including $12-35 core charge. They both came with lifetime warrenty. For any reason your allowed to go swap it out. Napa simply wanted $171 no cap or rotor with 3 month or 12,000 mile warranty.
O' Riley's had the same remained Cardon for 99.99, and then informed me they carry a new distributor named richporter part number is richporterGM23. It looks good, still gonna change the cap and rotor to the Borg Warner I have. Who knows if it looks good and brass terminals why not keep and save the cap and rotor. Cost is $116. Lifetime warranty. They said for any reason I can bring it in to swap.
Has anyone tried the highporter and have had luck? Or stay with Cardon. I'm leaning at the rich. With that in mind I'm sure my stock coil will be fine no need to install the msd coil I have. Gonna use search engine but thought I ask about wires too. Tried Taylor 8mm, wasn't bad but one usage, an hotter cabable wire would be preferred.

 

[Don W.]

Re: Good distributor options

For wires Taylors are good. 2-3 suppliers here. Also a step up would be these"

http://www.syty.net/forums/showthread.php?t=100082

I have the NAPA unit, no issues. No clue who builds the thing. I use thier "brass term" cap. Make my own rotor as shown earlier. IMHO good wires, properly protected with boots etc., especially #6, and the correct plug gaped around .028 are the secrets. But I've said that before. Lots of valid opinions on the plugs. Just have to be willing to pull and read them. Probably the only true way to know what's going on in your motor.

 

[fivetodrive]

Re: Good distributor options

Don, have you ever thought of a putting in a phaseable rotor?

And also how do you make yours. I would love to see what the top of the rotor looks like...


After reading this thread I looked around and watched this. Pretty interesting!

 

[Don W.]

Re: Good distributor options

Precisely what I'm getting at.

To my knowledge there is no phaseable rotor for our trucks.

Here is a blurry pic of the rotor cap relationship.

Although I don't have a pic of the top of my rotor here's one "in progress." Use a new Sy rotor though. :rotf:

Start with a Sy rotor and a new but old-style Ford rotor. (There may be others) Remove the rivet only on Sy rotor. Disassemble the Fort to get the T shaped piece. Reassemble the Sy with the Ford rotor. It's handy to have a spare dist and a cap you can cut open to set the gap between the "new" rotor and the cap terminal. Once set I use a small brass screw to finish leaving no exposed screw underneath beyond the edge of the plastic. I trimmed the unnessary portion of the T. You can see in my previous post where the rotor is "burnt" how far off we are.

HTH