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Discussion Starter #1
Hi All,

I am slowly getting the engine bay of my 67 Duetto back to what I believe/understand to be 'as factory'. I think I am nearly there but I am not convinced with my current choice of ignition coil (Bosch 'Blue' coil) - see pic. below.

What is the general con-census as to what was the original fitment ignition coil - from the factory?

I am not after what is 'best' - I am after what was 'correct'.

What does everybody think?

Many Thanks in advance,

Gary
Factory RHD 1967 "Duetto"
 

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Wow, beautiful restoration.

I think you're right - not the Bosch blue, which probably didn't exist in 1967. My guess would be a Marelli branded coil, with an external, ceramic resistor. The early coil brackets had a flat surface (about 1" X 1") where the resistor mounted. Here's a photo I grabbed off ebay of the type of coil, resistor and bracket I'm describing:



Admittedly I'm not an authority on when Alfa transitioned from Marelli to Bosch coils, but I believe it happened after the Duetto era.

My only other comment would be to suggest that you zinc plate the housings of the voltage regulator and horn relay, since you have replated the other underhood hardware. When I judge a car, I look for consistency; evenly-dulled plating on all parts gives that "barn find" look, while fresh plating on everything reproduces the day-it-left-the-factory feeling. A mix of the two just doesn't look right. (And yes, I expect some hate mail for this remark from those who don't get concours).
 

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Discussion Starter #3
Thank you AlfaJay - very much appreciated, trying to find the evidence is the hard part - at least I would know what I was looking for (or trying to recreate).

I have been thinking about the 'zinc plating' for a while - you have prompted me to put it on my official 'list of jobs'.
 

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Looks wonderful.

I doubt the head nuts were chromed either, but if it were mine, I sure wouldn't be removing them:))
sometimes you can go too far.......forget Pebble Beach, Ville d'Este, Goodwood and the rest....get it to how you want it to look, and then drive it:)

that bosch blue coil does look a bit modern, I agree, so I'd just get a new vintage look black or silver coil and stick either a Marelli or Bosch coil sticker on it, depending what yours originally was.

is the dizzy original, or has it been replaced with electronic?...in which case I guess the bosch blue was necessary.

(I notice the B.S.AU seatbelt standard plate on the bulkhead, so its a UK car correct?)
 

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Thank you AlfaJay - very much appreciated, trying to find the evidence is the hard part - at least I would know what I was looking for (or trying to recreate).
Gary: Confirm with Duetto experts, like ossodiseppia or Wille R. before taking my word for it.

If they confirm that the Marelli coil with the external resistor is correct, put a "wanted" ad in the classified section - many BB members probably have these.
 

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If you buy a coil and wire in the Marelli ballast resistor then the coil primary resistance should be about 1.5 ohms.
 

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My March 67 RHD 1600 has Bosch 041 dizzy and Bosch black coil (with brown top). Coil is mounted pretty much exactly where and how yours is, with same bracket.

Just out of curiosity, given some other recent discussions about Duettos...Is there a booster mount hiding under that washer bag? Doesn’t look like it...
 

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Just out of curiosity, given some other recent discussions about Duettos...Is there a booster mount hiding under that washer bag? Doesn’t look like it...
US-delivery 1600cc Duettos came without boosters. Don't know why.
 

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Bosch coil, black with brown top with internal ballast resistor. Inscription reads "BOSCH germany". Then below "importe d'allemange".
 

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Discussion Starter #12 (Edited)
Thank you Vivace - I have been reconsidering the cam cover bolts for a while now - I have the originals, so may put back (undecided).
 

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Discussion Starter #13
Thank you spiderserie4. Have have been reconsidering the head nuts as well - I have the originals, so may put back (again, undecided). Good spot on the BS AEU seatbelt plate. It is indeed an original UK car - delivered straight from the factory to London in June 1967.
 

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Discussion Starter #14 (Edited)
Alfajay - I have been consulting with ossodiseppia for a good while now and he has become quite familiar with my car. Most of what you see in terms of decals come from osso :smile2:
 

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Discussion Starter #15
Hi Ranz, Your black coil with brown top set up has come up my other research so well may be the answer. Have you got a picture of it you could post? Failing that could you describe the decal that is on it - if you have one. In answer to your other question I do not have a booster bracket under the washer bag - I understand that they did not come with boosters - not until later.
 

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Discussion Starter #16
Tom Frasca, Thanks for looking in your parts stash - is it the black with brown top Bosch one, which is emerging as the forums 'concensus' on the matter.
 

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I have been reconsidering the cam cover bolts for a while now - I have the originals, so may put back..... Have have been reconsidering the head nuts as well - I have the originals, so may put back (again, undecided).
I'm not getting what's wrong with Gary's cam cover and head nuts. Is it that the plating is too bright?

Given how fresh the rest of his underhood looks, I wouldn't say that the cover & head hardware stand out as incorrect. My instincts would be to leave them as they are.

Back to coils: I might run a slightly incorrect coil before I would run a 50 year old coil. A little Google research shows that Porsche suppliers carry Bosch coils with brown tops. One of these could be painted black and the appropriate decals ("BOSCH germany" & "importe d'allemange") applied (does Osso make those?).

Something like:

 

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I use the original coil in my 101 Sprint Veloce because it runs well and do not see any reason to upgrade a car that is only driven on special occasions. I know that 105 cars used Bosch electrics and not Marelli.
 
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