Marelli Dizzy Questions.

[vangelislaz]

Hope someone here help me, I have some questions for a Marelli dizzy type: S145C.

1) In the first photo you see three Marelli rotors. The left one was on the dizzy till took it of. This ones measures in resistance about 7KΩ . In the center there is another one (the black) with the exact fit and shape and is a new, having about 5kΩ of resistance. The last on the right doesn't have an exact fit , needs some trim to get it on, has 0ΚΩ of resistance (no carbon). So, for the above dizzy which one might be the right choice, or the diff resistance is in between the tolarences, or , just for different kind of wiring ? The car is a Berlina 2000 (euro) with normal ignition. In case I will change to an electronic ignition , still the rotor must be remained the same?

2) On the second photo , you see the bottom of the Dizzy. How much needed to have the gap (vertical end play)?

3) As looked more precisely there , I found these springs different. Is this normal ? In case I confused the place of the springs, where must have each one ? Or , doesn't matter?
Thanks!

[vangelislaz]

as for the second question (end play) , what is the total correct gap without the needed washers.

[Alfacliff]

the springs are different. at least in my 74 and my son's 69. the endplay isnt very much and isnt very critical. the left two rotors look like mine. I have never measured the resistance of them. while the dist is out, you might measure the resistance from the point arm to the spade lug on the bottom, the one to the coil, mine had corroded and had high resistance. since this is in the primary side, it really hurt the ignition performance.
cliff

[vangelislaz]

Thanks Clif,
Well, yes I do understand what you are talking about the resistance you mentioned but, this resistance I've measured is not the same. It refers only to the rotor itself. The two rotors on the left side of the photo have an enclosed carbon resistor! Thus, there is a resistance between the central point and the distribution terminal ( to plug wiring).

[Alfacliff]

that would be for radio noise supressor. not the most high tolerance resistors around.
cliff

[Roadtrip]

Scumbag pervert reported

[vangelislaz]

what is this?

[papajam]

Roadtrip reported a spammer and the spammer's post was deleted.

[60sRacer]

Resistors are sometimes built into the rotor in place of carbon plug wires. Either provide a high resistance to reduce the spark-induced radio noise. Alfa often used stranded copper wire like racers use; this leads to pretty high radio interference. Some of the bosch wire sets had the resistors in the metal shield cap at the spark plug end. Other set ups used these resistor rotors.

In any case, the resistor is just to reduce the radio interference; no other effect if you remove them or use a rotor without.

Robert