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Coil

Posted: Mon Apr 18, 05 9:47 pm
by Rich
Any one got any sugestions as to why a coil should get hot(and I mean
HOT)whilst just cranking the engine??
Its a brand new MSD Blaster 2 on a Chrysler electronic system,with a stock orange box..The engine fired a few times but I stopped when I found this problem.The starter got fairly hot but thats to be expected with a fresh motor but the coil put it to shame in the heat dept.I think the next stage was flames :violent3:

Posted: Tue Apr 19, 05 8:47 am
by Anonymous
The ignition supply bypasses the ballast resistor when cranking the motor so prolonged cranking is battery voltage not run voltage which is lower

this is how i understand the ballast and ignition supply :?: :?: :?:

Oh and the Mopar orange box isn't really up to much but thats by the by

Posted: Tue Apr 19, 05 2:21 pm
by Dave999
The coil gets hot when electricty flows through it

So if your points or control box is switched so the coil is on, the elctricity is flowing through the primary it gets hot. This depends on crank position which dictates distributor position, and your ignition type.

I think normal/orange/gold boxes switch the current on to the coil until they get a pulse from the induction trigger.

normally when the motor is going current only flows through for a fraction of a second before being switched off to make a large voltage across the secondary and hence a spark.

if the motor is turning slowly or is not running then the current is on contstantly or nearly all the time. hence hot coil

MSD blaster is probably a lower resitance coil so it will flow more current and make more heat.

A coil will only bulge or explode if it is oil filled and the oil boils not all round coils are oil filled


The ballast resistor arrangement is swicthed out of circuit during cranking due to the current the starter motor draws.

in normal running the current available to the coil is maximium and the voltage across it is held at about 8 volts due to the divider circuit it is in with the ballast resistor

during starting that voltage and current would drop considerably due to the work the startermotor is doing (no good for starting a car). So the coil is switched into a circuit that gives it the full 12 volt supply while the key is in the start position i.e the ballast resistor is switched out or the low resistance part of it is used depends on duel or single ballast

Keep in mind however that voltage will stilll be reduced anyway due to starter cranking.

you can get rid of the balast resitor and Mopar control box if you run a control box from a GM HEI distributor ?17 and a 12 volt internal ballast coil or a square HEI coil. ?9- ?30

these work up to 9000 rpm and work as well or probably a damn sight better than the mopar parts. 1980s tecnology rather than 1960s.

can provide details if anyone wants to do this upgrade

Its GM!!! (downgrade?)

basically a diy of this

http://hemiperformance.com.au/whatsnew/ ... s/hpi2.jpg


Dave

Posted: Tue Apr 19, 05 7:45 pm
by db
As one for whom ignition electrics is one of the black arts, like alchemy or plastering, how do i know if this will work on my rip-snorting 360?
Do i need to spend ?1000000s on an MSD ignition (6AL has been suggested)?
Will Daves setup (A) work (B) be any less effective?
What advantages (other than a posh red & silver box) does the MSD have?
Ta :D

Posted: Tue Apr 19, 05 8:15 pm
by Anonymous
If your cam is less than 245 duration and your compression ratio is below 12.5:1, then our FBO kit will work great.
The only reason we don't recommend our system for motors that have more than 245 duration and higher than 12:1 is that it does not have a rev limiter or a multi spark under 3000 RPM like CD ignition systems (MSD). Big cams produce very low cylinder pressure because of bleed off at low RPM and most need that multi spark system to help ignite the fuel.

?85 for the ecu, coil, cap, rotor and ballast resistor. MSD do a rev limiter that works with this kit that we can get.

FBO is also developing a MSD of their own

So it all depends on the comp ratio and cam if they are higher than the numbers above you need that MSD if not then it's a waste of money

Posted: Tue Apr 19, 05 9:03 pm
by Kev
My ballast went boing! at the DoorSlammer Nats the other year. TyreFryer got his Sister to bring one over for the Sunday (Hero! :D ). Meanwhile I ran with the ballast bypassed all day Saturday. Sunday morning dawns and I'm blaming Philth for spilling beer in the passenger footwell. He was adamant he hadn't so I had a taste of it :shock: Yep you guessed it! Me Mallory coil mounted up on the inside of the firewall had boiled some of it's guts out. Man! That is one 'orrible taste! Still running fine though.....

Posted: Thu Apr 21, 05 7:55 pm
by db
Gawd, here we go again.....
Anyone know anything about my cam? :?

I do know it's an Ultradyne .580" (and that it's been reprofiled).
Don't suppose theres any way of measuring the duration without pulling the cam is there?

It's certainly under 12.5:1 comp, think Alex reckoned 9:1.

If your kit will work Neil i'll go for it when funds allow (i'd like to pay for what i've already had first tho....:oops: )

Posted: Thu Apr 21, 05 8:32 pm
by Anonymous
The reprofiled bit certainly makes it interesting to say the least!!

it can't be that big a cam if the compression is 9:1 :?:

I'm sure the FBO kit will work great, if not i'll take it back can't say fairer than that.

What distributor have you got?? Only asking cos you'd have a hell of a job getting a stage 2 with a custom curve without the cam specs

As for the fuel stuff no worries mate it's all safe here, it's actually quite useful having it all here as there's been lots of people drooling over it all

Posted: Fri Apr 22, 05 3:02 pm
by Dave999
The suggestion i made was just for an upgrade to a non ballast resistor (hinderd) ignition that doesn't use the mopar box (60s technology) and can run a high power coil.

MSD box will provide multispark and such like,
its professional kit.

depends what you want to do

if the motor is tending towards race rather than road and the modifications are making it harder to ignite the fuel. i.e compression is low at low RPM due overlap induced by long duration cam or non standard phaseing then the MSD will serve you well. The multispark capability up to 3000 or so RPM is a good thing. however after that point and up to 7000 or so RPM the GM module does exactly the same thing for a fraction of the cost.

(stable, fixed dwell to high rpm, high power spark, overload protection....its all there)

the MSD is a race setup and costs race prices. not stricktly necessary for a road going car that goes racing ocasionally

I wanted a standard looking, cheep upgrade without having to drill any holes in anything
mines a pretty standard engine 10.1 compression, never sees more than 5000 RPM and runs good on poverty unleaded.

it was fouling plugs with the old points setup
it was running better with a bog standard mopar box
it would probably have run a bit better with an orange one (but i don't rev particularly high so why bother, timeing stability above 5500 rpm is not a worry i have)
it runs much better with a GM HEI box.

I bought one of these

Image

and because i was skint

my old fave

the bosch blue coil (only good for 4 and six cylinders) is a 12 volt coil not 8 volt

(i could have bought an HEI specific coil).

rigged it up thus

W = positive lead (+) from the pickup
G = negative lead (-) from the pickup
C = negative side (-) of the coil
B = positive side (+) of the coil

and put a bypass lead across my ballast resistor.

the module was $17 the bosh blue was ?9

hemi performace in Australia charge $450 for this lot bolted on to a recondictioned dissy !!

My attitued was general service parts are cheap and reliable and the technology is now mature after 50 billion units have been shifted.
I don't have an ECU controlled car but want to make use of a similar power coil to a modern car (50 000+ volts and a higher current)
I pay cheap and do it myself or i Pay a lot for shiny silver and red box with functinality that i won't need.

this can be triggerd off the standard Mopar electronic dissy

or convert ya points one with this

http://www1.jaycar.com.au/productView.a ... &SUBCATID=

and this

Image


module part numbers

for module and coil in Australia

Bosch ignition module part number BIM024
Bosch Ignition coil part number HEC716

If you want to get it from US

these are all the same thing

KEM #E200
Standard #LX301
Motorcraft #DYG-216
Napa online ECHTP45
Wells DR100
Niehoff DR400
AC DELCO D1906
summit ACC-35361

http://www.texasperfparts.com/store/scr ... roduct=585

The Aussie guys use this setup on their LPG cars running compression ratios up to 13.1

or buy a full HEI dissy (with integral coil pack) and turn down the case and shaft to fit ya mopar engine. easier said than done.

if it doesn't work well you are down ?30

Dave

Posted: Fri Apr 22, 05 7:32 pm
by Dave-R
Chrysler were the first major manufacturer to use electronic ignition accross their product range and did so from 1973.

The "orange box" is BTW the STANDARD unit. Sometimes there is confusion over this.

My understanding is that it is nothing more than a solid state switch.

It is not an amplifier (again there is often confusion over this). All it does is switch off the current to the coil primary when it gets a signal to do so from the distributor.

So without changing the coil how does changing the "switch" effect performance?

Well again my understanding is that the only way you can change things (for better or worse) is by changing the amount of time that the "box" takes to switch off the current and how long it keeps the current switched off before switching it back on again.

So I would guess faster in both cases is better?

Voltage to the coil was always kept lower than 12 volts to make the contact points last longer. Electronic ignition does not use points so you can get away with a higher primary voltage and conversions should always include a lower value ballast resistor so that you can take advantage of this.

15 years ago I fitted a Jacobs Electronics "Mileage Master" ignition system to my 440. I had noticed an improvement going from points to electronic but the step up to a CD system was a huge leap. You could feel the extra torque.

That system has worked fine for all these years but I fancy a change for one reason or another. Mainly because it does not work as well over 5000rpm as other performance systems and also because I want to include a built in rpm limiter.

I am still toying with the idea and need to discuss it with Linda etc but as far as I can see I have several options open to me including keeping the existing system or switching to a MSD system or similar.

However Jacbobs, despite being sold off, still has products on the market and I quited liked the look of the "Pro Street" system when it first came out years ago. If it only worked slightly better than the old Mileage Master unit I have then I would be a very happy man indeed.

Link to the system below.

http://store.summitracing.com/partdetai ... toview=sku

Posted: Mon Apr 25, 05 6:37 pm
by Dave999
Changing only the switch does affect performance.

and its switching speed, not having a mechanical switch and not running a condencer that makes it so. no stray back emfs no reduced power to the coil due to arcing as the points open etc .

Aussie mopars never had orange boxes as standard. it was a 3 or 4 wire blue or grey box...the orange box was considerd an upgrade due to its ability to work better at slightly higher RPM. which means they changed the value of a resitor and a capacitor and charged a fortune for the 'UPGRADE'


That jacob's kit looks very flash.

makes mine look positivly agricultural :) but then again your engine probably cost twice what my car did.

horses for courses

the reason transistor assited ignitions which is what the orange box is, get called amplifiers is because they (transistor assisted ignitions) were sold as spark amplifiers for years. maplin electronics still sell a kit called that.

they do make a bigger spark (slightly) but i think the word amplifier is a bit strong.

anyway

here is the specifications of mine :)

http://www1.jaycar.com.au/products_uplo ... 3334r0.pdf

these chips cost ?2.50

Dave

Posted: Mon Apr 25, 05 8:53 pm
by Dave-R
Nothing wrong with low-buck when it works just as well. In fact more power to your elbow. :D

I suppose the more cylinders you have the faster you need to switch the current too? So a V8 or V12 unit would be a higher rpm upgrade for a 6 cyl version?

Posted: Tue Apr 26, 05 6:34 pm
by Dave-R
Actually because of the features on the MSD system I will problably end up using one of these.

http://www.msdignition.com/ignition_18_6520.htm

Posted: Wed Apr 27, 05 6:11 pm
by Anonymous
That's all enlightening

our kit will work great on anything that is lower than 12:1 and 245 @0.50

it's designed for a v8 will work like a dream on a 6cyl and needs a higher resistance ballast on a 4 or bye bye coil.

And with it having a ballast you can always swap the wires and give it battery voltage for short periods at the track.

Works great on Mopar of course but also on everything else and looks stock