Coil selection question

Here you go:

http://www.pertronix.com/prod/...ame/coils/chart.aspx

Haven't used Bosch plug wires since way long ago - I always use Taylor 8mm HI-Energy type

http://www.jcwhitney.com/taylo...e-sets/p3091728.jcwx

Bruce when I went to the Pertronix I just hooked up my existing coil. It worked great for a week, then failed--certainly because it was, like, 30 years old. Greg (Wolfgang) gave me a spare and that's been on the engine ever since, running fine for four years.

That was an original Made in Germany Bosch Blue coil - you're right on the 30 years old.  What a day that was!  

Four years? - more like 7-10 years now I would guess.

Pertronix recommended the Flamethrower 40511 so I ordered one.  Trying to get this thing running correctly and removing any potential issues. 

They also have two different spark plug wires sets: the "7MM Stock-Look plug wires" and the "8MM Flame-Thrower MAGx2 custom wires".  So I asked "What is the benefit of the 8MM versus the 7mm spark plug wires? Why would I buy one versus the other?"  Interestingly, they responded with "Nothing! Just the look of a factory 7mm. The internals are the same with both parts." 

. 

Regarding the 7mm vs 8mm plug wires...the only real difference is the diameter of the wire covering. 8mm wires have a thicker covering and in most cases depending on manufacturer are more resistant to heat, automotive fluids and crossfire when plug wires are by necessity run close together than 7mm wires. If you are going for a 'vintage' stock look in the engine bay then the 7mm wires would be more 'period' correct.

I've always had very good results from Taylor made 8mm plug wires on V-8's, also I've used MSD 8mm plug wires with excellent results...I have run these wires on the Cobra for a number of years...more expensive than most but IMO worth it.

Don't know if MSD makes a VW type kit for 4-cyl, yet they do have 'universal kits' that the buyer cuts/fits for custom use...buyer has to install plug ends. Buy any make of 'universal kit' for a V-8 and you have two sets of plug wires for 4-cyl...that is a bit of savings over buying a pre-made VW kit at near the same price. You do have to have the correct crimping tool to fit the plug ends and a decent pair of electrical shears to cut the wires to a squared off end though...I have this crimp tool:...a bit pricey at between $70-80 though but I have done a bit of custom plug wire looms on my cars over the years and well worth it...mine came with 7mm, 8mm, 10mm dies.

Pertronix flame thrower coils will have a tendency to fail if they are mounted nearly upside down(as in the case of most flat four VW engines) and/or exposed to a lot of heat. They are not the only make that has this problem. If you look at a lot of racing cars you'll see that the coils are often mounted straight up or as straight up as can be done and high and away from any direct engine heat.

When I first went to all MSD ignition, distributor, 6AL adjustable rev limit box,and Blaster/Blaster2 coils there was an issue of coil failure in just a short time because the coil was mounted sideways laying flat in the stock Ford location on the front of the intake manifold(I was running a 4-bbl at the time on a Edlebrock intake manifold). Thus the coil got very hot, I spoke with the MSD techs after two coil failures and the first thing they asked me was where and how the coil was mounted. They then recommended I move the coil from the engine, mounting it upright away from the engine and any header heat. Then they sent me at no cost a then new Blaster2 coil, at the time it was a new to the market coil, in exchange for the 2 failed ones...pretty good customer service for doing that when they didn't have to.

Heat and mounting most coils upside down or sideways is a coil killer!

"Pertronix flame thrower coils will have a tendency to fail if they are mounted nearly upside down(as in the case of most flat four VW engines) and/or exposed to a lot of heat."

Yup - pretty much the same for ANY coil mounted on the fan shroud.  They heat soak all the time and eventually fail.

That's why I mounted my Magna-Spark coil on the driver's inside fender wall and away from the direct engine heat.  It takes a longer coil-to-distributor wire to get to it (a spare #1 plug wire makes it), but it'll probably last forever.

Thanks guys.  My coil is already mounted on the driver's inside fender wall but lying down.  Easy fix to rotate and have it stand straight up.   

Why are they mounted horizontally? To save money on a shorter plug wire?  Mine is mounted in that manner.

Thanks

It really shouldn't matter whether they are mounted vertically or horizontally.

What DOES matter is if they are mounted away from a heat source.

Thanks, Gordon. It is on my list.

Art

Sorry to disagree with you Gordon, but you are wrong in stating "it shouldn't really matter whether they are mounted vertically or horizontally."

Coils are oil filled but are not completely filled thus creating a small air pocket and if mounted sideways will expose the upper windings to the air in the coil, overtime the windings corrode and the coil will begin to fail, moreso if heat is present.

I figure if the those who design/build/market the coils recommend mounting vertically or as vertical as possible they must know what they are talking about...

Ford, for instance, used to mount coils on the front of the intake manifold laying flat, coil failure became a real issue on the high performance engines of the time during the mid-late '60's. Sometime in the '70's after experiencing a multitude of coil failures brought into dealerships they changed the mounting location to either the inner fender or the firewall, mounting them vertically and away from engine heat...Ford engineers must have known something or they wouldn't have changed the location and orientation

Like I said in another post: "If you look at a lot of racing cars you'll see that the coils are often mounted straight up or as straight up as can be done and high and away from any direct engine heat."

By racing cars it is most seen in 'old school' Formula Ford and Formula VW and most of the other classes as well, depending upon ignition systems...

If that's the case then perhaps upside down would probably be okay too as we see alot of that.  

Upright and vertical!!! Guys I'm not B.S.ing about this or trying to be contrary I believe and know for a fact that it works...over 10yrs now on the Cobra and I have never had another coil failure, nor have I had one on the '33 Vicki, the '56 F-100 or the '55 Chevy...but I did have one die on the Speedster before I relocated/replaced it, shortly after I got the car last Nov it died and would not restart...dead coil!!!

It's your choice, your car...do what you want...I was just trying to help out

Does vertical mean with the wires up or the wires down?

Oil-filled (and cooled) coils dissipate heat better than epoxy-filled, but are more prone to failure from vibration.  Epoxy is a poor conductor, so, if heat is a major factor, use oil-filled, mounting upright with wire on top.  This is one of the myriad of topics on which car guys agree to disagree.

Well, dang, whodda thunk it??  Sideways is a no-no.eh?  Just put in a new coil, and it is sideways.  Will look to see how to get it right-side-up.  Sh#!  The stuff you can learn hanging around here.

Kelly, didn't you have a coil crap out at Carlisle?

I learn something new every time I visit this site! 

Al, Not real sure what happened at Carlisle, might have been coil, might have been breakerless ignition.  Anyway, replaced both, and all was good.  Old coil registers proper resistance, but if it is good or not, I dunno.

Remember swapping Jack Crosby's extra coil for yours and no joy? I do.

I think most of the problem was the loose screw on the distributor base plate, or the loose nut behind the wheel!

FYI, if you can mount the coil upright, wires on top, and away from heat, it's probably a good idea to do so. But what do I know?

Stuff like the relative merits of oil-filled vs epoxy coils are the kind of things that keep OCD people (like "someone *ahem* I know") obsessing about for days.

I read a lot, and obsessed about it even more. I wasn't sure how I was going to mount the coils, and I wanted to be able to orient them in any direction if needed. In the end, I went with epoxy for the twin-plug motor... but ended up mounting them upright on the shroud, so I really should have done oil-filled.

You know what? They work just fine.

Something I DID find out in this process: Pertronix points replacement modules are less than stellar in their operation. Electronically, they are really "dirty" (quite a bit of electrical noise). The CB Black-Box does not like them. The Summit Racing house brand RPM switch (for the shift-light) does not like them. We're all sipping the Pertronix Kool-Aid, and the stuff is less than ideal.

... now I'm worried about those coils again...

Another reason I did crankfire.....can't beat the accuracy. Love the way yours came out, Stan. We will swap cars someday, just like I do with Mr. Drake!

Vertical= coil wires up

Thanks, Danny, but I'm sure your car is faster.

You're right: crank-fire is where it's at. I may (down the road) go to a crank-positioning sensor to feed a signal to a spark controller (probably MS), but rather than use wasted spark (like the smart people would), feed the distributor and canister coils so I can still have the "bundle 'o snakes".

It's only money. And time. 

Danny, you are probably running one of the best systems out there. You can not beat them for accuracy and power. I have a friend and fellow club member that has a '67 Nova w/502BB W/2-4bbls and he runs a crankfire ignition setup...that car, when cold and not been started in awhile fires up like right now...BAM! and it never misses a beat and the timing is always dead on.

You got it! Manufacturers save a few pennies on each car built, multiply that by thousands of vehicles sold and that is a big cost savings overall...but as in the case of Ford it came back to bite them in the butt with coil failures brought into their dealerships.

I personally have never used them but Hot-Spark Electronic Ignition conversion kits are tauted to be one of the best on the market. Not prone to failure due to vibration or heat or just crappy manufacturing like Pertronix, they are available for VW Type 1 engines for about $70, plus you need to get the required Beru, German made coil to go with it.

Probably one of the best things you could do if you want to get rid of points is to change the distributor to a pure electronic one like from MSD, Hot-Spark or Mallory...they are all very pricey though

"The nut behind the wheel"  -- well, yes.  There are two of them.  The one that actually holds the steering wheel on the steering shaft was a constant source of trouble for me, coming loose because the other nut behind the wheel was cranking it too hard, upon occasion, I guess.  Tried lots of ways to tighten that bad boy up, but it would wiggle loose after a while.  Never had the right tool, I guess.  Anyway, a little blue Loktite on the thread seems to have done the trick.

I am sincerely enamored with the idea of the crank-fire system.  Would need to know more about how to install, what to buy, etc.  And i did recently check on something Pip mentioned about stock dizzies, wherein they seem to wander a little bit.  So I had the timing light out the other day, resetting the timing and spent a mo watching the mark dance around when fully advanced.  And dance it does.  Not sure how much of a deal that is, but am really curious about what it is w/ these systems that makes it do that.  Anybody have a guess? --That last is always a dangerous piece of bait to toss out in front of the SOC, but I say: let 'er rip.

Frazoo....it's not rocket science here... -)

Check out Megajolt's website. Ford EDIS is what makes their sparks go round.

It's fun, less filling and very  refreshing....keep the pickup gap set right and forget it.

Frazoo - Timing bounce can be caused by (among other things):  slop in the mechanical drive of the distributor (both cam and distributor drive shaft), slop in the mounting of the (moving) advance plate inside of the distributor (that which the electronic module or points is affixed), and just plain poor design of the electronic module(s).  Sometimes, too, you can get what seems to be timing bounce because the timing light is picking up spurious signals from other spark plug wires - this is often cured by picking a different test location or routing for the timing light pickup wire.

Because of that mounting plate slop (and it doesn't take much slop to make a noticeable difference), the trigger signal to the Hall-Effect sensor can move all around a base trigger point as the plate slop allows the sensor to see the trip signal sooner or later (and weaker/stronger, too).  Imagine looking at something through a pair of binoculars and then having someone jiggle the binoculars a bit - same effect on the spark as the trigger sensor "looks" for a trigger tooth to come around.  

If the electronic module design is weak, it could get mis-fires from spurious static signals, too (remember how much power is running through a distributor cap).

The biggest difference I've seen in reworking distributors is to have new bushings installed everywhere, including the pivot point for the advance plate, the actuator arm (if it has one) and/or the advance weights.  That makes them calm down a lot.  After that, getting a high-quality distributor body in the first place seems key, too.  Most of the original (German) Bosch distributor bodies were pretty good, as are those from Mallory.  The ones I used to deal with in GM trucks were (I think) made by Bendix, Delco or Echlin and were slightly better than OK.

All of this should show why a crank-fired set-up is so far superior.

Everything Gordon said is on point.

If you are using a distributor, and have the room, get one of the larger diameter models, such as Mallory or MSD. Lessens spark jump/crossfire under the cap.

Kelly, you're an engineer, think about it. How far are the magnets on a Pertronix from each other. Less than an inch, times 4 magnets. Any change in rotation or vibration will alter the spark consistency by a good bit.

Now compare that to 36 pulses per revolution on a 6" diameter trigger wheel. Hands down WAY more accuracy. One moving part.

OK, copy all of that.  I have an "009" dizzy, and who made it, I cannot say.  Whatever JPS supplies.  The Pertronix is new, and the coil too.  All in all, this seems to be working pretty good.  Not sure if a few degrees of wander here is really all that important. A few HP here or there?  After all, I am not racing, just looking for reliability. So, on to the more important stuff: what does one need to buy in order to have a crank-fire system? A piece here, or a piece there?  A kit that has it all? who makes the best one?

And yes, I are an engineer . . .

Yeah, the trigger is (usually, not always) a "Hall Effect" sensor, which converts proximity to a magnetic source to a relative voltage.  Depending on the mean voltage selected to "trigger" the coil circuit and what the range of that trigger voltage is, you get several related things:

1.  The trigger magnet is moving past the sensor in an arc, meaning that the voltage  follows half a sine-wave (positive side only).

2.  The range selected for the trigger can be short (partial collapse of the coil's magnetic field) or long (more complete collapse).  This is similar to varying the dwell angle on a set of points to allow longer or shorter amounts of the "normally closed" state.  Dwell using a Hall Sensor can be varied by increasing/decreasing the positive trigger voltage range (usually in the associated circuitry). 

3. Dwell can also be slightly adjusted mechanically on some electronic distributors by moving the sensor closer or farther away from the reluctor (the 4-pronged gizmo spinning on the distributor shaft).  I seem to remember having a specific distance for that on AC/Delco distributors, but I usually set them up with a matchbook cover - Gud E'Nuff....You could NEVER use a metal feeler gauge to do so, because it would screw up the sensor.  Different modules/designs require different spacing, reluctor to sensor.

4.  The typical VW distributor has only 4 trigger points, each 90 degrees apart at the distributor.  In the crank-fired system with 36 trigger points, you can fire something every 10 degrees +/- whatever your dwell is, AND depending on what you program into the controlling software for relative advance or retard.  The software does all that and all it cares about mechanically is what, in it's 360 degree cycle, is the current position of the crankshaft. 

Recently, I've seen a running Carerra 4-Cam engine utilizing a trick, crank-fired ignition.  It uses a 4-toothed crankshaft reluctor and retains both of the original two distributors (both still driven directly off of the cams).  The crank provides a double-spark trigger (one for each distributor) by setting the sensors about 180 degrees apart, and the original distributors take care of routing the spark to the proper cylinder.  Spacing of the two spark pulses can be varied either electronically in the ECU, or mechanically by moving the sensors up or down.  The engine starts and idles rock-steady and stays steady all the way to 8,500 pm.  

I'm sure that Danny's spark is just as rock-steady, even given the 36-tooth approach to triggering the coil(s), because you're coupling a very close tolerance relationship (crankshaft position to exact position of each piston) to a programed, repeatable spark event ("X" degrees before top dead center of each piston).

Danny:  Does your system automatically retard cylinder #3 to keep it cooler as does a VW/356 distributor?  

Couple of things:

The sensor in most if not all crankfire systems is actually a VR sensor, or Variable Reluctance. A magnet inside a coil makes up the sensor. It senses a ferrous object and the space between and ends up creating a very nice square wave. The missing tooth says hey, TDC is coming in 9 teeth from NOW. The missing tooth is 90 degrees BTDC. I've seen people drill 35 holes in an aluminum pulley and put bolts in. I chose to lathe down the Ford wheel and fit it to my crank pulley.

I'm sure you know Gordon, but some may not know that the Hall effect is a moving magnet and an induced voltage in a coil.

There is no retard for number 3, my system is off of a Ford Escort with an aftermarket controller. I don't need it to retard that cylinder anyway, as I'm not running an OE shroud and cooler.

Kelly, when I had my 009 installed, I read +/- 5 degrees at 3000 rpm. The spark changed 10 degrees at that speed, and I'm just going to say it's pretty darn significant. Maybe it's due to loose bushings(no) or mechanical slop(yes) or the advance plate(maybe). Doesn't matter to me, it was unacceptable.

Set your timing at 28, 30, whatever. It could be as high as 37 in my case as I run 32 degrees! Can you say detonation?

Kelly, you need a toothed wheel and a VR sensor, and a mount for both. You also need either a throttle position sensor and mount for your Webers, or a vacuum can and ports to all 4 intakes for a MAP(manifold pressure sensor).

Then you need an EDIS brain and a coil and all the wiring connectors to fit, and then you need a Megajolt box. And of course, a laptop to load the timing map.

Sorry about the previous wordy post!

Here is my install: http://www.autosportlabs.org/viewtopic.php?t=1753

Gordon, there is a new and inexpensive name in EFI/spark control

It is based on an Arduino Mega, and can be built relatively inexpensively:

http://speeduino.com/forum/index.php

In a VW, you can't do sequential spark, which would enable you to retard #3. For that, you'd need a cam sensor. The best we can do is wasted spark, unless you put a magnet on the cam gear and drilled the case for a sensor. The speeduino has a 16 x 16 map instead of Megajolt's 10 x 10, but I find it to be completely adequate.

Well, that is quite a lot of info.  The theory (Hall effect, crank and cam timing, etc.) I have no problem with, understand all of that.  It is the practice that I need schooling on.  My take from the above is that there are no "kits", and that these systems on the VW engines is a home-brew sort of thing, adapted and cobbled from pieces and parts from here or there.  Hmmm . . .what to do???