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Simple question

Superunknown

Well-known member
Joined
19 Jun 2006
Messages
337
Apparently i need new distributor caps and rotor arms. Im guessing i should buy 2 dist caps but what the hell are rotor arms and how many should I get? 2 as well??
 
Philip1972 said:
Butzi said:
rotor arm is the bit spinning inside the dist cap.

Yep thats right.

All the old, slow unrelaible cars have them.... :wink:

characters mate, characters! Some cars have them, some cars don't!! :wink: :lol:
 
Two??
Have I missed something. I thought it was one cap with six leads to each of the spark plugs.

And to help Justin out..The rotor arm spins in the dist cap, there is power going into the bas eof teh dist cap and as it spins it connects with one of the terminals inside the cap and sends power down each lead to the attached spark plag.

The rotor arm is driven off the crank turning the engine hence the spark delivered to each plug is in time with teh cylinder firing sequence.

Make sense!!!!
 
It's definitely two. It's a quirky design of the 964. It needs two because each cylinder has 2 spark plugs (which means there are actually 12 spark plug leads - 6 for each distributor). The two distributors are linked by a drive belt in the housing.

This is what a rotor arm looks like Justin - you obviously never owned a morris marina like I did all those years ago :wink:

ig015%20rotor%20arm.jpg
 
Philip1972 said:
Butzi said:
rotor arm is the bit spinning inside the dist cap.

Yep thats right.

All the old, slow unrelaible cars have them.... :wink:

Whilst this thread seems to be turning into Shop 101, to quote the American, I'm presuming that new cars do not have rotar arms?

What do they have instead? :oops: :oops:
 
Right, I'm no expert but...

Modern electronic ignition does away with the distributor to distribute the voltage from a single coil to each spark plug. Instead, each cylinder has its own coil (coil pack) and the ecu tells each coil to spark the plug at the correct time.

To prove I'm no expert I don't know if the 993 has the old or new system. The 996 and onwards have modern electronic ignition.
 
pretty sure all the 993's have dizzies.........mine certainly does
 
993 has twin distributers just like the 964, with te breathing tube so the belt doesn't snap.
 
As you can probably tell, Im mechanically inept! Just to make things clear on my part then, I need 2 distributor caps and 2 rotor arms? (or 1 rotor arm?)

And no, I have never owned a morris marina :shock:
 

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