Bizarre twin plug set up ??
 

Purchased an 1982 targa without any background info. Can anyone help me identify this bizarre twin plug set up? It has twin MSD. Car runs good now but the (rear?) Distributor will need a new belt soon and I have no clue where to ascertain one of those puppies.


http://forums.pelicanparts.com/uploa...1401630663.jpg


http://forums.pelicanparts.com/uploa...1401630681.jpg

Could it just be a single plug with an extra msd in case of failure? I only see one coil. And that black thing in the first picture only has 4 terminals, not 6.
Does it actually have 12 plugs?

There was a thread years ago about cam driven twin plug setups. Search for Grady Clay's response on the subject.

In a way its a "hidden" twin plug setup.

No twin set up, 12 plugs second cool is hidden to the left of engine mounted near the fuse panel, just the way the photo is it looks like possible 4 but it def has six plug wires on the back dist cap. I will try to get better photos and maybe even from under side to see the belt drive off the cam.

http://forums.pelicanparts.com/uploa...1401662831.jpg


This pic shows the second coil

Wow, cool setup!

It set like old airplane engine .Double ingition .

I don't see it. Where is the 2nd coil?

Its up on the side on the right - black, kinda stealthy.

I have heard of these set ups but I cant remember where I read about them. I wonder if the belt that drives the 2nd dizzy will even be available? Maybe its just an MFI belt?

Posting this for a visual. A 962 engine (not mine) with that setup. It uses the "regular" dizzy in the typical spot to fire six plugs and then an additional dizzy off of one of the cams to fire the other six.

http://forums.pelicanparts.com/uploa...1401715663.jpg
http://forums.pelicanparts.com/uploa...1401715323.jpg

Some more photos
 

From the under side

http://forums.pelicanparts.com/uploa...1401755443.jpg


From the top side in the back

http://forums.pelicanparts.com/uploa...1401755476.jpg

Two more from the top side
 

http://forums.pelicanparts.com/uploa...1401755645.jpg
http://forums.pelicanparts.com/uploa...1401755655.jpg

MFI belts are wider than that. You might be able to find something from Gates on McMaster-Carr or SDP/SI that would fit as a replacement. Have fun changing it though.

Yeah it looks like they clearanced the shock mount cross bar with a BFH. Looks like something I would do. I think I can see some numbers on the belt i n one of the pics, maybe if you can get it off you could source it. I would be scared to lose the timing if I took it off with the motor installed.

You could remove the cap on the rear dist. and observe the orientation of the rotor when you set the engine to TDC. Then mark it. When you put the belt back you should be able to hit that mark. Should be obvious if you are +-1 tooth on the belt.

My concern would be the changes in timing over time as the belt wears and stretches out. How do you tension it? what tension do you set it at if its adjustable?

Note there is no belt on the 962...

Interesting setup...

I have tried and tried to find the previous post on the subject. I can't seem to find it but I know its there.

Not to hijack in any way as I realize the OP's second dizzy is being driven by a belt via cam, but I thought I would share these pics. Several years ago, Neil Harvey of Performance Developments (a premier 956 and 962 engine builder) was handling all of the machine work on my 930 engine. I decided to go twin plug. This was one of the options he mentioned. Obviously borrowed from his years with the 962 engine:
http://forums.pelicanparts.com/uploa...1401818030.jpg
http://forums.pelicanparts.com/uploa...1401818046.jpg
http://forums.pelicanparts.com/uploa...1401818066.jpg
http://forums.pelicanparts.com/uploa...1401818088.jpg
http://forums.pelicanparts.com/uploa...1401818104.jpg

^^^this dizzy would have been attached to the turbo oil scavenge pump, which runs off of the driver's side cam.

Really cool!

Yes exactly where my belt is connected