Alot of talk on here about dist lately. I am lost and am hoping someone can clue me in, I have alot of questions but will try and ask one at a time so my brain dosent hit overload.

Slant gurus please follow this post and help me to understand things better. Thanks

1st question- If you guys had to choose one particular performance ELECTRONIC or POINTS ( please NO HEI suggestions at this point ) dist for your 225 what dist would that be any why?

I have been reading about dist with plastic gears, metal gears, aluminum pods, better factory advance mechanisms ect.

I am lost.

For your truck I would choose a Super Six calibrated factory electronic ignition distributor. I would use it to trigger an HEI system, but if you don't want that then I would use it to trigger a standard Mopar electronic ignition system.

These days "points ignition" and "performance ignition" are pretty much mutually exclusive.

I will also add that wiring in an HEI system is easier and cheaper than wiring in a stock Mopar system, and maintaining an HEI system is cheaper, too.

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Casually looking for a Clifford hyperpak intake for cheap.

Most of what your reading about different curves, gears, springs, pods etc are all from the guys that have been through the trial and error portion of things. They have tried multiple set-ups in multiple cars and engine combinations. There is no real drop in peformance upgrade in that area, just have to mix match and tune until you find what works in your particular application.

To answer your other question, for performance and accuracy, electronic is the way to go. Basically need a magnetic pick-up dist, the ignition module, ballast resistor and all the wiring that goes between. If your converting from points, just do HEI, its simpler, more accurate, more powerful, and more compact (in case cleanliness is important)... HEI uses the same dist, but eliminates a bit of extra wiring and drops the ballast resistor.

Again its all up to you, we all run HEI for a reason, be it a daily driven stocker or a modded out lumpy slant, HEI is the most powerful and precise ignition you can set up. As for the timing curves, advance pods, weights, springs etc... Its still up to you to do the research both on what you want, and what you are about to buy to make sure it will all come together in the end. One tune will work great at first, but change vehicle weight, gearing, compression etc will require a different curve.

Maybe someone else will chime in and have something different to say, but that should pretty much answer your questions...

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"if it aint broke, fix it till it is"
78 Plymouth Volare Super Six wagon
89 Volkswagen Golf GTI 16v
92 Chevrolet K1500 5.7
98 Ford Escort ZX2 zetech

What Reed said.

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1964 Dart GT

It took me about a year to wrap my brain around all the different concepts involved with distributors and timing curves. This is much more difficult to explain via text than it is to just grab a distributor and take it apart and play with it to see how all the systems interact.

Start by remembering what a distributor does. The distributor performs several functions:

(1) it tells the coil when to fire. Points systems do this mechanically by opening and closing the points, electronic ignition systems do this electro-mechanically through the use of a magnet and an electronic pickup (Hall effect sensor). Points are subject to wear, electronic pickups are not.

(2) it directs the charge from the coil to the corrct spark plug wire through the rotor. This is where setting your base curb idle timing comes in. What you are doing when you turn the distributor to set your timing is changing the position of the terminals in the distributor cap in relation to the rotor. This is also why you have to have the rotor pointed roughly in the right direction when you install the distributor. The rotor needs to be timed correctly in relationship to the portion of the four stroke cycle each cylinder is going through.

(3) it changes the timing based on engine speed and engine load. Also, as the throttle is openend and as a load is added to the engine in various operating conditions, the timing is advanced or retarded. In both points and electronic ignition system distributors, there are springs and weights underneath the plate in the distributor as well as a vacuum advance pod on the side of the distributor.

As the engine RPM increases, the timing advances. The weights and springs (springs mostly) control the rate at which the timing advances in relation to the engine RPM. This happens because the rotor in the distributor is mounted to the governor which actualy moves in relation to the body of the distributor. Slots in the governor rests on pins which are part of the weights. As the speed of the distributor shaft increases due to increase in engine RPM, the weighs spin fster and centripetal force causes the weights to pivot outwards. The pins on the weights also move and cause the governor to move in relation to the body of the distributor. The springs control how fast the weights move outwards and as a result control how fast this mechanical tioming advance system advances the timing. Heavier springs make the timing advance slower, lighter springs make the timing advance faster.

The vacuum advance works differently. The plate that the points or electronic pickup are mounted on also pivots independent from the body of the distributor. The vacuum advance pod on the side of the distributor has an arm that attaches to the plate. When vacuum is supplied to the pod it retracts the arm and pulls the plate towards the pod. This advances the timing. Note that this is also why you always set your base timing with the vacuum advance hose disconnected.

As soon as the throttle is opened, vacuum is applied to the pod and the timing is advanced. The vacuum advance pods came in different rating in two respects: the minimum and maximum vacuum levels at which they would operate and the amount of advance the pod would provide.

Over the years many different components were used in the distributors to control what is called the "timing advance curve" or the timing curve. The timing curve is the combination of how much advance is provided and under what conditions (RPM and vacuum) the advance is provided. A purely mechanical advance curve will generally be a straight light or a slight slope, but won't have any peaks or valleys. Vacuum advance is used to add timing advance in high vacuum situations (such as light throttle cruise).

Factory distributors used different springs, weights, governors, and vacuum advance pods depending on the emissions package, weight, and intended application of the vehicle the distributor was originally intended for.

Once you have grasped all of that, you can see how you can use different parts to fine tune the distributor and come up with a timing curve that is matched to your engine in your vehicle for your intended purpose.

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Casually looking for a Clifford hyperpak intake for cheap.

Recently while I was rewiring my truck, I took the time to rewire the HEI module that I converted to a few years back.
I also took a picture of it.
I wanted to mount this in the original location of the Lean Burn computer. The engineers designed the computer housing to hook into the air intake for the engine to help with keeping the computer cool, so I thought it would a good place to help keep the module cool.
Well I disassemble the computer and found that after pulling the electronics out of the housing I was left with an 8 3/4 inch X 4 inch area for a heat sink. So I picked up a piece of 1/4 in aluminum plate to fit in the housing, shouldn't have any heat sink issues. Some would say that I went thru allot of trouble to mount this module. But the housing is designed with 2 openings one where air is drawn in by the other opening that is connected by a hose to the breather intake hose, there by drawing cooler air across the entire inside of the housing. I have been driving it like this since July 2007 and have not had any issues.

Here is a picture of the rewired module and ready to reassemble.
https://skydrive.live.com/redir.aspx?ci ... 6xyhouBGNQ

I kept the vacuum advance pod in there just to plug that hole. Make note of how the pod is orientated when you pull the 2 halves of the housing apart, or it will not go back together easily.
https://skydrive.live.com/redir.aspx?ci ... 8yvF3fYYso

all the wires I used when I did the conversion were all there plugged into the computer. There were 2 wires going to the coil, 2 to the distributor and 1 ground wire.
Here is a link to a PDF of the wire diagram from the factory service manual and wires highlighted that I used.
https://skydrive.live.com/redir.aspx?ci ... s12eOvYLZI
doing this mod I was able to eliminate 15 wires from my wire harness.
I used a 6 pin GM weatherpack that I got from junk yard for $2 to make all the connections. Weatherpack is so that it will disconnect from main harness for removal if any repairs are necessary. Do not attempt to buy this weatherpack new from NAPA just the blank housings are $15 apiece!!!! By the time the guy had figured all the pins and seal I would have had $45 in just one six pin connector. I found mine on a K5 blazer for $2. I was able to reuse most of the seals and bought new pins as needed. I think I ended up with $10 or less invested in the connector.
Originally when doing the conversion I had tried using a dizzy out of 73 dodge truck. It had to much mechanical advance, 30 degrees total if I remember correctly. I grabbed one from a 78 Volare with Super Six setup and it made huge difference. I also used the Blaster 2 coil as in the article. There was no ballast resistor either.
Hope this will help.

Dave

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86 Miser 170,000+
2 1/4" exhaust
Holley 1920 #55
HEI MSD BLaster 2
17.8 mpg

...can be found on this board. For example, Reed just walked you through the basics of the distributor and how it works. Nicely done, Reed.

Don't worry. As you learn from the board folks, you'll see that there is a solution to whatever your application is. The answers are out there, and the board is here to help you.

Some of these guys have been running/building/experimenting with slant sixes for decades. Figure out what it is that you're looking for in your particular situation, and there are answers for you.

Also, take advantage of the search function of the board. There is a huge wealth of information already posted. Taking some time to read through, follow some of the strings; you'll learn a ton in no time.

brian

Pretty much the points (no pun intended) of everything concerning the basics and some finer details have been covered.

The fact is the argument goes down like this:

Points were good back in the day, but since it uses a mechanical means of actuating the coil (the points or contacts), tend to wear out and right out of the gate the system starts to degrade.

You can get a Petronix setup to replace these items and that will make things more solid and not have to buy the consumables and the procedure to gap and dial them in (in a car it's not hard, but can be time consuming, on a machine it's quick task since you can see what you are doing and spin it up if changes need to be made).

The other draw back to the points distributor is the lack of 'tuneability' in the core. With these units up to 1971, to keep the curve from over-running the points and causing a misfire they come with two heavy springs, also the mainshaft has static or fixed spring posts which do not allow for an end user to be able to adjust the posts to put tension earlier or later on the springs. In 1972 the body and posts were exactly like the 1973+ EI distributors. Another item to note, is that the pre-1972 body is cast in a way that will not allow for a 1972-1980's EI mainshaft to be used as the adjustable plate contacts the body casting in a few areas, and grinding is just not worth the time considering an EI distributor body is easy to get.

The EI distributor give rock solid timing without the 'contacts' wearing out (if the gap is too tight or the set screw loosens, then you will have to replace the reluctor wheel and pickup as it will shear off the teeth). EI allows for tighter dwell and reaction for higher rpm use that typically caused points scatter or ignition breakup (the invention of dual points helped overcome this to some extent). It is easier to replace a faulty module every decade than it is to pull the distributor and replace the points every tuneup or 6 months.

EI also allows a fair amount of spring changes, vacuum advance options, and tuneability.

That being said...

EI is finicky to timing changes in regards to cam phasing. If your timing chain stretches and wobbles more than a few degrees the vehicle may not start, or may die. I have had a car run fine on points, then run cruddy, then using a timing gun find I had an 8 degrees timing mark wobble on an original setup, but it would start and get me to work or the store just fine (but have bad idle or die on deceleration on occasion).
EI can also be tanked by EMP, so if you need your truck after WW3, or it needs to stay running after the cops use their pulse gun on your vehicle for whatever reason, then you want points. (I keep a couple of these 'just in case'). Another case for points, is that if the EI dies, it's literally a 5 minute procedure to swap the distributors, land the two wires, and convert the vehicle back to points in an emergency (I think THOR has the record at 5 minutes, observed...)

So for best 'performance' (mileage, tuning/curving, racing)...EI is the boss here, for emergency reliability the argument could be made for points.


Gears are only worth noting in passing:
The stock nylon gear can take a pretty good pounding at lots of RPMS (mine have had 50K miles and multiple 6000 rpm passes on them without a hiccup). It's only after a decade of heat cycling that they get brittle and fracture. Having the oil pump or cam seize, or walk, or a chunk of something getting in the gears will destroy them or shear off the teeth, and it's really not hard to install another gear.

The need for the hard core racer, and now with the harder steel billet roller cores, the need arises for something a little more rigid for high rpm use...thus the desire for the bronze gears talked about, these are not really needed for daily driving and would not be of benefit to the daily driver (other than to lighten his wallet). At one time Echlin offered a soft Iron gear (Echlin DG-404) over the counter for people that wanted one (although, there again, at the time there was no need to buy the $5 gear vs. the $2 nylon gear at that time). Having a cam with the gear cut wrong (like some Comp Cam blanks a few years back), oil pump failures, will still wipe this gear out and since Echlin stopped offering them, they are just not worth the $$ to use.


2 cents,

-D.Idiot

Thanks to everyone that posted, a big thanks. I just hope some of you only had to copy and paste from somewhere else and didnt have to type all of that. It will not go to waste, give me some time to digest ( hopefully not a year and Ill prob. have more questions.

Thanks again

You did a great job, I would have had to have done similar if I had kept all my original components like the factory air cleaner assy ect. Factory look but an up-graded ignition, a bit bit of time figuring it all out but well worth it in my opinion.

Thanks again Duster, just to clarify ( curious ) wasnt there a factory dist ever offered originally in the slant with the bronze or steel gear.

I thought I had read that but I may be confused.

Havent made it thoroughly yet to your second post on this thread but how would I get a Super six dist, reading thru recent posts here I see that someone ordered one from a retailer and just got lucky in his own words.

Something about the can being aluminum if that makes sense, I can go back, find the post and copy and paste here if that will help.

When I got the two EI distributors I have now I went to local parts store and ordered for a 78 or 79 Dodge truck. I figured that would be my best bet but I cant for the life of me see where the canisters are marked with any sort of vacuum advance notation like I think I should be seeing if I am reading the posts properly so how do I know what I have?

I can post pictures later this evening after work if it would help.

You can spend time scouring ebay or go to NOS dealers with a part number for the Super Six distributor, or you can piece together your own out of parts from othr distributors.

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Casually looking for a Clifford hyperpak intake for cheap.

Not that I've seen unless the earliest prestolites came with an iron gear, but that's overkill (and I think you'd have to lap the gear in to prevent a lot of shavings in the pan).

Super Six distributor is a 3874876 (also found on Federal one barrel cars after 1977), note that if buying one over the net to check it out, there have been a lot of people that just mark a distributor with no tag as a 3874876, and once you get it, the guts bear out it was a 1974 3755042 long slot special...

OEM EI bodies are aluminum and not cast iron like the remans. Late OEM vacuum pods had the last 4 digits of the distributor part number and a bar code on a sticker on the pod (super six can would be 4876). Just eye balling the 'arm' of the can in the open spot before it 'hooks' the advance plate will have a stamp of the degrees of distributor advance (x2 for timing light or crank advance)...if you have the correct one it will have an 11.0X or 11.0R stamp on the arm (and so would a can from a feather duster/dart lite, but they are different).

If it's an aftermarket can the back of the pod facing the distributor body will have a stamp like AH-7...these are now standard generic tags regardless of the brand you buy...so an AH-11 is a VC-239 (arms now marked and actuate to 8.5), an AH-12 is a Feather Duster can replacement (still stamped 11x and actuates like the feather duster can), AH-7 is a VC-184 for 1973-1974 (stamped 8.5x and actuates like the 8.5R 1974 cans)...

FYI, stock truck distributors tend to have a 13R governor, and heavy springs with slow curves...none are the same as car distrbutors, but lots of junkyard trucks have car dizzies in them as it was easy to grab one from a wrecked Dart and keep driving regardless of the ping involved.

Thanks again Duster, very informative