Re: Solid State Ignition

Posted by Rusty O\'Toole On 2010/4/28 18:02:23

I finished the conversion on the Porsche and found out a few things.

The Ford TFI will work with the Porsche distributor. I used one off a Probe that had the module mounted on a heat sink on the rad support. The cast aluminum heat sink mounts in place of the original module and looks factory. I used Turbopackman's instructions and cut down the original Ford wiring. The coil wire was wrapped with tin foil so I left it on and grounded it. Assuming it was for suppressing electronic interference.

A spare module off a Hall effect distributor works just as well even though it has extra connections. I just ignored them.

The Porsche coil barely worked. Not sure if it was coil failure or just not compatible with the Ford module. I tried a universal aftermarket coil, a Mercedes electronic ignition coil, a Japanese coil off a Chrysler minivan with Mitsubishi engine, and Ford coil made for TFI. The Ford coil was by far the best. It threw a spark well over an inch long.

With the Ford coil and ignition I opened up the spark gap to .035" which is twice the factory recommendation (.55MM). The engine starts instantly if you barely touch the key. Have not driven it on the road yet except for a brief 1/2 mile test but it ran fine then too.

I plan to reduce the plug gap to .030 or .028 because the distributor cap is very small with not much room between the plug wires. I'm afraid of misfires or crossfires.

So, the Ford ignition works with points and puts out a spark that compares with any late model electronic ignition. Your stock coil may or may not work with it. The stock Ford coil works great.