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Discussion Starter · #1 ·
I have two distributor assemblies in my possession. Bosch is on my recently purchased 79 and the Marelli (which I believe is stock) is in a box-o-parts that came with the sale.
Is there a better one for my series 2? Is there a common problem with Marrelli which may have caused the PO to install a Bosch?

Opinions are appreciated.....

Thanks
 

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71 Berlina 74 GTV 17 Giulia Q4
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depends on the advance curve, maybe po thoght the bosh had a more perfromace curve. Some don't like them because of spark scatter in the smaller bosch cap but that's more probably for racing apps than day to day driving. The bosch is eaiser to loosen with a 10mm crows foot than the Marrelli.
 

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It depends upon which models of distributors that you have and the state of tune of your engine (and the condition of the distributors).
 

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The bosch is eaiser to loosen with a 10mm crows foot than the Marrelli.
It's also easier to access the points on a Bosch. Marelli located the advance weights above the points, making it tough to get at them.

If you want to install an electronic igniton module like a Pertronix, there seems to be more clarity in which model fits the Bosch distributor. It's basicly the same distributor used on a 4 cyl Volvo, Mercedes, BMW, etc.

In terms of which has the better advance curve, it depends. What's the tune of your engine? What p/n Bosch and Marelli distributors do you have? Are the springs still fresh? E.g, do the distributors still provide their original advance curves?
 

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It's also easier to access the points on a Bosch. Marelli located the advance weights above the points, making it tough to get at them.
That's the whole idea of the slotted drive disconnect, you pull the distributor to replace points rotor and condenser on the bench at which time you can clean and lube the shaft and the advance weights. When you re-install it goes right back in the original position without monkeying around with a helical drive gear.
 

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It's also easier to access the points on a Bosch. Marelli located the advance weights above the points,...
Exactly.

And because of this, the Marelli dizzy shaft is top heavy compared to the Bosch which has the advance mechanism immediately above the upper bushing. So the Bosch bushings should last longer given less bushing sideloading (assuming equal bushing material, of course).
 

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what problem? Getting rid of five hundred clams you don't know what to do with?
 

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Exactly.

And because of this, the Marelli dizzy shaft is top heavy compared to the Bosch which has the advance mechanism immediately above the upper bushing. So the Bosch bushings should last longer given less bushing sideloading (assuming equal bushing material, of course).
Is there a pile of Marelli distributors laying around with worn out bushings? Haven't heard of or seen any. The weights on top makes it easy to service and inspect, with proper attention they last forever.

My point is - there is nothing wrong with the Marelli distributors, I actually prefer them.
 

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Didn't say there was anything wrong with either distributor. Just pointing out major physical differences and that a component that is more heavily weighted on one end can cause faster bushing/bearing wear than a component that isn't.
 

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I don't disagree but of the three Marelli distributors I sent for inspection and checking two had a wide scatter pattern and were not suitable even for road use. That's why I have moved onto 123s and keep the Marelli units should the next owner want them.
 

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I agree with Jim and Stuart. Most Marelli distributors that I have handled have had worn bushings and in some cases worn centrifugal mechanisms. I switched to a 123 several years ago and I have no regrets.
 

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I haven't seen worn bushings but the fly-weights get worn and develop a lip that catches on the center cam sometimes. I know most of these old Marellis probably have a few hundred thousand miles on them and although their design makes it easy to clean, service and even repair the advance mechanism most of them were neglected. Plus, as far as I know, there are no longer parts available so you can't really rebuild them.

My only point was toward the question of "Marelli vs Bosch?" whereas I don't personally see any technical advantage or superiority to the Bosch over the Marelli other than the fact that you can probably buy a new one but you'd be better off buying a 123 in that case. That's what I'll do if I can't maintain the Marelli anymore but for as long as I can I'd prefer to keep everything on my Spider as original as possible.

One of the things I really like about it is that it's one of the last examples of a car that was purely mechanical, with virtually no electronics outside of a radio. Kind of like a Grandfather clock, you wouldn't want to pull out the movement and put in something with a double A battery. Of course I have no problem with others doing whatever they wish with their cars, I'm only speaking for myself.
 

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71 Berlina 74 GTV 17 Giulia Q4
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I looked at the 123 very closely and finally decided I didn't want to pay for 10 curves I'd never use. Robert at Shadetree has a sun machine and does quite a bit of racing and recurved an old bosch I had for a very reasonable price and he nailed it. that one is in the spider. I have an RML in the GTV and it is ideal for my motor and what I've done to it. Just seemed like a wast of 200 bucks to me, but that's just me.
 

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Discussion Starter · #15 ·
The main reason i am asking was that I am having some problems getting the Bosch Points so I thought maybe I would rebuild and install the Marelli.
Centreline are out of stock with no idea when they are to get more. I ordered them on Tuesday and I had to phone them on Friday when i did not receive any information. It was then that they told me they were out of stock.
I ordered from IAP tonight. One screen said they were out of stock yet another screen said they had stock when i asked for 1. Asking for 2 or more came back " out of stock".
I guess I will call them on Monday and see.
Appears this item is getting hard to source.
Are there other good sources for parts?

I did get the Bosch to dwell correctly (well I managed to get about 56') and it is working decent for now but my points are very worn and need replaced.
 

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I got the same line from Centerline last time I tried to buy new points for the Marelli. IAP had them so I bought two. The thing about the points is that you can virtually infinitely restore them. It's the condensers you should look out for because, without them, the points only last a few hours.
 

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ClassicAlfa has the Marelli points (or had if there is a world shortage).
 

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I looked at the 123 very closely and finally decided I didn't want to pay for 10 curves I'd never use.
How do you know what is the best curve for your motor if you don't experiment? I was surprised that the Jim K curve worked best for me. The extra performance from that curve is easily worth $200 to me. It is distinctly different from the Shankle, Bosch and Marelli curves.
 

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Ed, thank you for your comments....the 123 is a great device...I have no interest in the Company.... but it solves so many problems that I have bought several of them and the results have been amazing.
 

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I should add you save the cost of buying another distributor if you find the best curve for your engine then modify the motor so that it needs a different curve. The curves also are not subject to change due to wear in mechanical componenets or weakening springs.
 
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