Incorrect Coil?

[citybreeze]

Good evening everyone.  I am looking for advice as to whether I've got the correct/incorrect coil fitted to my Spitfire or not, and what the remedy might be, or what to use if upgrading to electronic ignition. 

This is for a 1969 Spitfire mk3, FD 1300 engine, with a Delco type distributor and standard points setup.

I have a Bosch 0221119030 model coil fitted.  It says 12v on the label, but I think it might be a 'ballasted' coil so maybe not 12v (?) as the Label says "use only with external resistance 1.8 ohm or electronic ignition".  I don't believe there is any external resistor fitted, nor the black/pink cable I've seen mentioned on other threads. 

Everything is taken apart at the moment while I'm painting the engine bay, so I can't wire anything up or test with a multimeter. 

So, I think I've possibmy been running a 'ballasted' coil without any external resistor; would this cause damage/running issues?  I've had issues in the past with an uneven idle and lack of power above about 50mph, could there be a link?

Can anyone recommend what coil I should have fitted?  

Would it be better to buy an external resistor to add to the existing coil, or to buy a new 'non-ballasted' coil?  The current one looks (externally) to be in good condition.

I'm considering putting in an AccuSpark electronic ignition module at some point.  Would this alter which coil is needed/recommended?  I wouldn't want to buy a new one now only to have to replace it again later when changing to electronic ignition, if at all possible.

 

Thanks in advance,

Matt

 

[johny]

yes also with a meter you can measure the resistance of the low voltage side of the coil: around 3 ohms is for non ballasted and half of that for ballasted. If you install electronic ignition you must have the correct coil or risk invalidating the warranty/blowing it up...

[dougbgt6]

Confusingly coils for a ballasted system will some times have 12 volts printed on them. The only way to tell is measure their resistance, 3 ohms for non ballasted 1.5 -1.8 for ballasted. 

I think the ballast wire you've read about is white with faded pink stripe, but I don't think you'll have one, more likely a resistor mounted on the bulk head or near the coil.

Doug

[Pete Lewis]

Matt     the built in ballast wire  would be a dull white and pink trace 

its made confusing some coil manufactures mark the coil with the basic car voltage when its also clearly marked as requiring a resistive ballast ( as you have found)

if the ballast wire doesnt exist and there is no ceramic dropper  one near the coil then you are feeding a 6-8v coil with 12-14 volts this doubles the current amps and the HT output

this can burn points cook condensers blow rotor arms and destroy caps  as its is all very overloaded 

a std 12v coil of 3 ohms would be like a lucas DLB101 or 105   a ballasted would be DLB102   but you have a ballasted coil already 

it can cook  some electronic units 

without getting into supposed sports coils and suchlike as said std kit 

the coil resistance across the two terminals as

non ballast is 3 ohms 

 ballasted is 1.5 ohms   

 

cant say about accuspark but they should sell a  coil matched to their electronic specifications /ability

Pete

 

 

[johny]

Certainly the coils on ebay with that part number seem to be for use with resistors so it would appear its not the same as the standard one fitted to your car. A previous owner might have installed a resistor somewhere and you can only tell this by measuring the running volts as described. Even without a resistor it would work especially as you have points but could result in increased points wear and insulation breakdown of ignition components...

[Josef]

The Mk3 wasn’t fitted with a ballasted coil from new. So unlikely that you’ll have a ballast wire built into the loom unless someone’s done a good custom job!

[dannyb]

I also have a Bosch 0221119030 model coil which was fitted to my 1500 Spit. 

It says 12v but it is definitely a ballast coil. 

Danny

[NonMember]

Just to be pedantic, it's actually just as wrong to say "6V coil" as it is to label it "12V" - in fact probably more so. The only correct labelling is "12V ballasted". You are not applying 6V to the coil. You are applying 12V (well, nearer 14V actually) through a resistor. The characteristics of coils means that, when the points first close, the coil does see the full 12V+, and it only ever gets down to 6V if the engine speed is low.

[Pete Lewis]

yes if the points are open you will measure 12v   the points have to be closed to measure the on load voltage when ballasted or you get a duff result 

Pete

[citybreeze]

Thanks for the replies everyone.  I've gone back to do a thorough search through the wiring and I cannot see any evidence of an external resistor being fitted by previous owners.

I was quite surprised that new coils are not as expensive as I was expecting, so I think I'll just buy a new Lucas DLB 105 or possibly the Accuspark equivalent for about £25 or so. 

I'll probably swap out the condenser, rotor, points, and cap, just in case they've been damaged.  I've got new spares lying around anyway. 

Cheers all!

 

[Pete Lewis]

some new  condensers are very poor copies 

here is some clues to watch out for    http://www.distributordoctor.com/distributor_condensers.htm

pete

[dougbgt6]

Yeh, if you cut it open and find very little inside it's a dud. If you cut it open and find long tightly wound  innards, you had a good one. 

Doug

 

[Clive]

16 hours ago, citybreeze said:

Thanks for the replies everyone.  I've gone back to do a thorough search through the wiring and I cannot see any evidence of an external resistor being fitted by previous owners.

I was quite surprised that new coils are not as expensive as I was expecting, so I think I'll just buy a new Lucas DLB 105 or possibly the Accuspark equivalent for about £25 or so. 

I'll probably swap out the condenser, rotor, points, and cap, just in case they've been damaged.  I've got new spares lying around anyway. 

Cheers all!

 

I would be buying the correct Bosch coil. The new lucas coils are not terribly good... probably same factory as te accuspark ones (ie unbranded)

At least the Bosch version is made by a company that makes proper quality OEM stuff.

[Badwolf]

Clive - Agreed, but if it's a counterfeit you won't know til it's too late.