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83 911SC 3,0 CIS barely passed MD emissions. I want to go the MSD route but can't seem to locate consistant info. MSD6AL seems right for the box, MSD HiVib Blaster coil seems to be the right one, and I believe I need a tach pulse adapter (pnXXXX?) I intend to keep the CIS (PMOs at $3k + cams + pistons ++++ is a bit much). My problem is that MSD varies their product recommendations at will, 101 Projects says one thing, others say something else. Empirical info needed: has anybody done the switch? and which MSD products were used? Plus what else: MSD harness? wierd plugs? wires?
TIA

Howard

I just did this for a friend on his '73 911 E. We purchased Webers for $1100 w/linkage, used an MSD Digital 6 box ( $ 400) , installed GE60 cams, RS cylinders w/ J&E pistons (10.3:1 CR) Magnecore plug wires, and it runs great. The stock distributor was used, not ideal , but it works, probably should be re-curved or swapped out for a '78 or '79 , but it's ok for now. The MSD tach adapter was not needed.

If you're going to retain CIS I don't see the need to go with MSD, the stock CDI box is great and I don't believe there would be any gain in converting. ( Steve will chime in about now...)
Just because you barely passed the MD smog doesn't mean you need to change the ignition, you could have other problems. JMO

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Thanks for the post. My diagnosis is insufficient spark at <3000rpm hence the MSD application interest. If I had $4-5k to spend I'd do some of what you guys did - except PMOs instead of Veebers - but I don't. The 83SC distributor is different and I don't need the recurve for CIS. I just want to order the right parts the first time.
Thanks again
john

Howard

All you would need is the 6AL or Digital 6, no tach adapter, no weird parts. I would go for magnecore wires though. Just connect the main supply to the starter terminal (battery), and the switched 12v to the switched 12v supply currently used for the CDI box. The tach output from the MSD box connects to the Purple/black wire on the stock wire harness. Late tachs , as far as I know would not require the adapter. The '73 nor the '78 required the adapter to operate the tach. Use high quality connectors and solder them/ shrink wrap,etc.

hmintz

If the tach doesn't work using the MSD tach wire, go back to the distributor output to signal the tach (the same wire you are using to signal the MSD). That's the same wire, and signal, that the tach used before you installed the MSD. Worked on my '76. To take full advantage of the MSD, plan on increasing the plug gap, per MSD recommendation. That alone should justify new wires (Magnecor, in my case). Enjoy. Easy installation, except finding room for the MSD box.

Lorenfb

Insufficient from a Bosch CDI? You've got another problem!

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Thanks for the replies. It seems that it will be a 6AL, Mangecors, and new plugs with larger gaps. Not much has changed since I installed my first CD ignition 34 years ago. Best plug wires/plugs with major gaps. If the tach doesn't work I'll try the suggestion above before i go for the pn8920 adapter.
Thanks again to those who tried to help.
john