Alfa Romeo Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
61 Posts
Discussion Starter #1
We're trying to decide what distributor to run in our 1962 Elva race car with 1300 Alfa Romeo engine. This is for racing only. So subtle advance curves are not relevant.

It came to us with a Marelli Plex and Marelli coil. I understand that was really a 1970s after market, but may have come on some Alfas or Fiats from the factory.

But, if this was 1962, what did the Alfas at the time use? I understand one of the options was the Bosch 041 JF-4 with black cast iron body, and perhaps one or more Marelli options.
Does anyone have more specifics on the Marelli options? What would the Veloce's have come with from the factory? And which ones might be best for this application?
 

·
But Mad North-Northwest
Joined
·
10,739 Posts
Unless you're doing racing where you're limited to factory options, just get yourself a fully-programmable 123Ignition distributor. Even for a street car these are way better than the stock options. For a race car it'll give you all the curve flexibility you've ever wanted, and the ability to run a low-impedance coil for high RPM performance.
 

·
Richard Jemison
Joined
·
7,590 Posts
And it looks like an old Bosch unit, without the points and advance weight issues. Being a race car it should have a correct curve. On the non-programable curve there is one perfect for the mouse motors that need the 40 degree plus max advance with a 1000 rpm initial advance point.
 

·
Registered
Joined
·
61 Posts
Discussion Starter #4
Thanks. Assuming we do not want to go with 123 to be period correct, what are the factory Marelli and Bosch distributors that would have come on the cars, and certainly the Veloce?

And Richard, what is a "mouse" motor?
 

·
Registered
Joined
·
61 Posts
Discussion Starter #5
Also, pardon my ignorance. But I looked at the 041 advance curve. Interestingly, it has a slow advance curve and full advance doesn't seem to hit until 5,000 rpm. That is designed for a road car and pump gas. A race car will have high octane gas, allowing more advance at lower rpms, and under full racing conditions, the car doesn't spend much if any time in lower rpm ranges. So I would not have expected the advance curve to matter. What am I missing?
 

·
Super Moderator
Joined
·
11,774 Posts
It's adjustable Jay. The springs and weights do NOT need to be changed. Only spring tension with an adjustable spring loom under the rotating plate. These have 36 degrees advance built into them. You can move it around. The Ausca grey one I pictured for you and one other I own just like it have much quicker curves.
 

·
Registered
Joined
·
61 Posts
Discussion Starter #7
Ah. I seem to have determined that the Marelli was the S73a. We have an S86b. They appear to be the same body, cap, rotor, and points. I'm assuming the difference are the springs and weights for the advance curve. True?
 

·
Super Moderator
Joined
·
11,774 Posts
Probably. I've only restored a few of those for Dave Brohan or Mike Besic. The JF-4 is a more "robust" mechanical, non electronic type distributor.
 

·
Registered
Joined
·
61 Posts
Discussion Starter #9
I have a Bosch 041 JF-4 on the way. We'll see when it gets here. But since this is for racing only, and we'll probably want to use Pertronix, we may be interested in using the Marelli body because it is Italian and came on the Veloce originally. I've found the Pertronix number to on a separate thread.

And interestingly, I found this comment on another thread from one of the contributors above:
"I increased spring pressure on the Plex unit in the race car to get it to a stable idle. However the curve is of no consequence since RPMs are never in the lower range."

That sort of supports my prior comment about the curve. We actually have the Plex unit on our car now.
 
1 - 9 of 9 Posts
Top