Alfa Romeo Forums banner
1 - 11 of 11 Posts

·
Registered
Joined
·
609 Posts
Discussion Starter · #1 ·
I'd like to convert from a single to dual point distributor on my Alfetta. It's a '76 SPICA car, the distributor coming out is the original one with new points, cap, & rotor (not sure of part number), and the distributor going in is a dual point Marelli S166B. I don't think it's a normal later model SPICA dizzy. There's a Flamethrower 1.5ohm oil filled coil on it with the factory ballast resistor hooked up, but I plan on putting the original coil back in and then eventually an OEM spec or Bosch Blue coil. Does anybody know how I would go about doing the conversion without adding all the relays and such associated with the later model SPICA? All I want is the slight performance boost from the dual point, I don't care about the emissions or fuel economy. (And yes, I'm aware that more points=more pain, my old man has already informed me of that.)
 

·
But Mad North-Northwest
Joined
·
12,406 Posts
If you want performance and no hassles why not get the 123Ignition distributor? Easy install and no points.
 

·
But Mad North-Northwest
Joined
·
12,406 Posts
Well, that'll do it, yeah.
 

·
Push hard and live
Joined
·
11,540 Posts
What leads you to believe two sets of points leads to more performance?

My understanding of the Alfa dual point set up was that provided a spark timing change at high RPM to improve emissions and fuel mileage.
 

·
Super Moderator
Joined
·
12,266 Posts
My understanding of the Alfa dual point set up was that provided a spark timing change at high RPM to improve emissions and fuel mileage.
Right! The two sets of points aren't positioned 180 degrees apart; they don't open at the same time. So if you wire the two sets in parallel, you will get too much dwell for a given point gap. If you narrow the gap to achieve the correct dwell, only one set would be open at the beginning and end of the coil discharge.

Back in the 50's Mallory and other companies made dual point distributors that were considered speed equipment. But 70 years later that technology has been superseded by electronic ignition such as Pertronix or MSD. If a Pertronix is beyond Alfa Tasteless' budget, a well-tuned single point system is probably the best approach.
 

·
Registered
Joined
·
4,388 Posts
If you are cash challenged, here's a suggestion. Fit a Pertronix II breakerless ign. to your distributor. This will allow you to keep the low resistance Blaster (which is superior on many levels) while insuring that you have a solid high-quality spark. Going backwards to a dual point ignition and a stock coil is not a good choice. There are better one's available.
 

·
Registered
Joined
·
609 Posts
Discussion Starter · #8 ·
Thanks for totally dodging the question. Now is there someone here that will actually give me the information I was asking for, or am I going to have to go elsewhere? All I need to know is where the second wire goes, I already know the one coming off the points goes to the negative on the coil. Does the other one go there as well, or what?
 

·
Premium Member
Joined
·
422 Posts
With the dual pt dist there was a throttle switch that once of idle the dist would switch from the idea retarded set to an advanced 2nd set. In my opinion this change is nit an up grade but just more headache. Good luck though
 

·
Registered
Joined
·
609 Posts
Discussion Starter · #10 ·
With the dual pt dist there was a throttle switch that once of idle the dist would switch from the idea retarded set to an advanced 2nd set. In my opinion this change is nit an up grade but just more headache. Good luck though
Like this?
1656980
 

·
Push hard and live
Joined
·
11,540 Posts
As I understand the two point system in the Alfa, it used a thermo switch to retard the timing at higher RPMS.
 
1 - 11 of 11 Posts
Top