Author Topic: Ignition Coil  (Read 4285 times)

PeterPortugal

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Ignition Coil
« on: April 28, 2015, 07:42:11 »
Hi Everybody,

I am a new member to the Forum but have already found a huge amount of useful information for which I am grateful.

I have recently started to get involved in improving my car (bought last year) which is a 1963 220SE Cab. Whilst cleaning up the engine bay I noted that the ignition coil is a Bosch blue and the ballast resistor is a red 1.8 Ohm unit. Does anybody know what the correct fitting would have been in period? I assume (wrongly maybe) that the 230 Pagoda would have been identical.

Also for the technically gifted is this combination of a Blue Coil with a 1.8 Ohm resistor a correctly matched pair?

Best Regards

Peter
1963 220se Cabrio
1968 280se Coupe

PeterPortugal

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Re: Ignition Coil
« Reply #1 on: April 28, 2015, 09:09:17 »
Guys,

After trawling through a lot of posts I think I already have my answer.

Original is "black" coil and 0.9 ohm resistor.

"Upgrade" is "red" coil with 1.8 ohm resistor.

I'm still not sure what the implication of a blue coil with a 1.8 ohm resistor is. I haven't used the car much so cannot comment on how well the system works. It starts ok though.

Thanks to "Naj" for providing many answers on this topic already.

Regards

Peter
1963 220se Cabrio
1968 280se Coupe

Naj ✝︎

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Re: Ignition Coil
« Reply #2 on: April 28, 2015, 09:44:40 »
Hi, Peter,

There is more than one blue Bosch coil.
The one used on later Mercs is meant to be used with transistorised ign systems and has a label on the coil saying so.
The output voltage is much higher and would probably burn out the points in no time.

Happy fixing
Naj
68 280SL

PeterPortugal

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Re: Ignition Coil
« Reply #3 on: April 28, 2015, 12:34:53 »
Hi Naj,

Thanks for your further clarification. I had arrived at that conclusion regarding the blue coil but I wasn't 100% sure and am out of the country and couldn't check.

Roger Edwards Motors checked over and serviced the car after I bought it and never remarked on this aspect so I'm kinda hoping the current arrangement is at least acceptable if not optimum.

I am going to buy myself a Bosch red coil and fit it.

What do you think of the mod (using relay rather than starter motor terminal) to bypass the ballast resistor during starting as per the later cars? Worthwhile?

Regards

Peter
1963 220se Cabrio
1968 280se Coupe

Naj ✝︎

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Re: Ignition Coil
« Reply #4 on: April 28, 2015, 12:45:05 »
Hi Naj,

What do you think of the mod (using relay rather than starter motor terminal) to bypass the ballast resistor during starting as per the later cars? Worthwhile?

Regards

Peter

Definitely worth it.

naj
68 280SL