Guts of SC distributor

[Randy Webb]

Does anyone know what's in the guts of an SC distributor? Does it use a reluctor (magnetic pickup)? And does that differ from a 964 distributor? Thanks!

[Early_S_Man]

Sc distributors have a centrifugal advance mechanism that controls the reluctor [spider] ... and a slotted distributor body to adjust advance.

Carrera 3.2 and 964 distributor have nothing but gear and gilmer belt driven rotors inside. No adjustment ... just a single hole to bolt distributor body to crankcase! All advance changes are made by the DME!

[emcon5]

Originally posted by Early_S_Man
Carrera 3.2 and 964 distributor have nothing but gear and gilmer belt driven rotors inside. [/B]

I don't know about 3.2s, but 964 distributors have centrifugal advance. Ignore the top distributor, but you can see them in the lower one.



This is a Rennsport conversion with SC trigger.

Tom

[UTKarmann_Ghia]

I've seen some distributor rebuild kits on eBay and such. What's involved in rebuilding one?

[Britwrench]

3.2 distributors do not have centrifugal advance. All timing changes are controlled by the DME system. The weights in the unit ensure correct rotor phasing..so the rotor always lines up with the distributor cap posts when firing.

[twin plugged targa]

Maybe some one can shed light on my Dizzy install which is on a 2.7 twin plug set up.
I know very little about this setup and only have the pics at hand.
Hope your diagnostic eyes can help explain the advance/retard system here as I thought it was adapted from a 964 but of course they use an ecu.
Rgds`Ben

[Bill Verburg]

964 distributors have centrifugal advance

Tom you contradicted your self in your post. Neither 3.2 nor 964/993 distributor has any centrifugal advance. All they do is distribute electrical energy and send cranshaft position info to the DME.

Steve does modify the 964/993 distributors for use w/ earlier cars that do need such mechanisms. The pic in your post is a distributor so modified w/ a mechanical advance mechanism from a pre DME car.

[emcon5]

Originally posted by Bill Verburg
Tom you contradicted your self in your post. Neither 3.2 nor 964/993 distributor has any centrifugal advance. All they do is distribute electrical energy and send cranshaft position info to the DME.

Steve does modify the 964/993 distributors for use w/ earlier cars that do need such mechanisms. The pic in your post is a distributor so modified w/ a mechanical advance mechanism from a pre DME car.

No Bill, The trigger in the top distributor is from an SC donor, installed by Steve Weiner. The advance weights were there from the factory. Pop off your lower cap and have a look.

Ben, The green wire going into the side looks like it is from an SC trigger. I don't think it is a Weiner conversion, as your base was modified with a slot to time by rotating the unit. On Steve's you need to undo a set screw and rotate the trigger assembly.

[Britwrench]

Bill is correct, the weights in the 964 distributor are for the same reason as the 3.2; rotor phasing and nothing to do with ignition timing.

[Bill Verburg]

Britwrench, you beat me to it. The mechanism pictured is a retard to make sure that as revs rise and whatever the timing dictated by the DME the current goes to the correct plug pickup. DME timing range is considerable, this is necessary to compensate.

Here is an exploded view of a complete 964 distributor

[Randy Webb]

Ok, so the stock 964 dist. has no advance (in it). When you put the SC inards inside it, does that provide a mechanical (i.e. centrifugal advance)? And is that the only thing it adds? i.e. the rotation direction is? is not? changed? The SC transplant does not add any retard or any vacuum control of any type does it?

[twin plugged targa]

Thanks emcon,
The green wire and end plug (which is partly hidden by an ign. wire) seemed to be held in place by a rubber sealant which was then painted silver to match the dizzy.
Any other info passed on from the pics would be a great help.
I may try and replace the Cap/rotor when I next see her, in an attempt to reduce my detonation problem.
Rgds Ben