brakehorsepower.net

About 18 months ago, I fitted my 1983 Plus 8 with a Mallory Electronic Ignition system complete with Mallory Coil and Magnecor leads.
The system came with a separate Ballast Resistor but when I wired in this resistor the car ran rough, but by by-passing the resistor and wiring the coil direct to the distributor the car ran fine. However, I have now burnt out two "modules" or "triggers" or whatever the technical term is,within the distributor, both lasting less than 12 months. I race the car, so mileage wise, less than 1000 miles.
My question is, I think!, has a 1983 Plus 8 got a Ballast Resistor already wired into the loom or should I be using the external resistor to prevent too much voltage going to the distributor and therefore burning out the trigger or amplifier.
The system was bought from RPI who seem to know about V8 engines, but when I spoke to them they blinded me with science! They suggested I send the whole distributor back to them and they will see why it failed. Before I do, I thought I would post this on the Forum.
Any suggestions, comments would be appreciated. Thanks.

If the car was orinaly fitted with points it would run a Ballast as std
if originaly fitted electronic it wont.
If fitted with points the.. pos/live wire to the ign coil (when ign on) should read less than 12v thus indicating a Ballast in the circuit,,
when the engine is cranked the circiut bypasses the ballast and puts 12v direct to the pos/live side of the coil ..which makes the coil give a boosted spark for starting.

things to check.. was the coil Supplied designed to run with a Ballast (normally says something on the coil).

or was the coil Supplied just a 12v coil?

when you fitted the new BALLAST was 12v present at the input side of ballast ( or did you connect a Ballast into an already ballasted feed wire).thus the new coil would run at an even lower voltage

I would to test this... Find out about the coil 12v or ballasted
if ballasted..
run 12volt feed wire from ign live side of fuse box direct to the ballast ..then from the otherside of the ballast to the +/live side of coil
the car should run fine

If not a ballast type coil
run the same 12v feed wire direct to =/live side of coil
the car should run fine

in both ways you will then be isolating any original ballast or non ballast wiring

hope this helps
it sounds like they may have sent the wrong coil ??

jack

Thanks for your reply Jack -
The car originally had electronic ignition so from that I deduce there would be no internal ballast. I think you may be right about the coil; the original was binned and a new one (supplied with the Mallory Distributor) was fitted. On speaking to RPI who sold me the whole kit, I think they kind of suggested that the wrong coil may have been supplied. I will need to investigate further and check the coil.
Cheers.

By the way, Jack, I had the SU's re-furbished and they look all shiny in their box! Now I just need to fit them!!

SU,s refurbished....
that means they will know my tricks then ?????? (have they told you)

jack

Andy
My 1980 plus 8 is still running original Opus electronic system with original ballast
I know I'm living on borrowed time !
So have purchased RPi replacement distributor, power amp and coil ref. DLB198
Their instruction is to remove my existing ballast and wire direct as Jack suggests
So the coil ref. may be a useful check against the one supplied to you ?
As I've not got round to fitting new system, will follow your progress with interest!
Ray

Hi Ray,
Have removed coil and Unilite "module" from Distributor. The Mallory coil has no specific wording on it, although it was supplied by RPI so I am going to send it back to them with the module and wait their reply. I kept the original electronic system which was working fine before I removed it! The phrase "if it ain't broke, don't mend it" springs to mind!

Will keep you posted.

With regard to the SU's Jack, do you mean all those welded holes in the butterfly valves??

Just the Butterfly valves then,, thats OK

jack

Andrew Faulds wrote:About 18 months ago, I fitted my 1983 Plus 8 with a Mallory Electronic Ignition system complete with Mallory Coil and Magnecor leads.
The system came with a separate Ballast Resistor but when I wired in this resistor the car ran rough, but by by-passing the resistor and wiring the coil direct to the distributor the car ran fine. However, I have now burnt out two "modules" or "triggers" or whatever the technical term is,within the distributor, both lasting less than 12 months. I race the car, so mileage wise, less than 1000 miles..

Try this http://www.gomog.com/allmorgan/MalloryUnilite.html

The problems you encountered must have been due to an errant hookup.,..perhaps a non-perfect earth to the Ballast Resistor.

The Mallory (if you have the Unilite) is an excellent unit, well suited to the engine. Simple, precise, reliable technology and an astonishingly improved spark (according to neutral oscilliscopes). However, they require a ballast resistor or a ballast resisted coil (which Mallory supplies..red top chrome coil). I have been running with the latter system for 120,000 miles on my Plus 8s. Without one, the photo-optic units will keep burning as will the coil shortly.

Lorne