Anyone out there have any knowledge to help me dig out of my most recent hole ?? Bought a 1968 Chevy re-pop tic-toc-tac. HOPING for circuit / dip to switch to 6 banger. No such luck. Also, as I have dug into correcting the signal for 6 cylinders, I have been informed that my MSD will probably not talk to my "vintage" tach. I know MSD has a module for "correction" to old tach tech. Been told it's OK at best. Also know there are converters for signal counting ; 8 to 6 cylionder. Question: WHAT's the best way ? I really like the tach. I really like the MSD. I really like the six cylinder. Anyone know how to make all these guys play nice together ?
I use the module with my MSD box and a Sun Super Tach, and it works fine - has for over ten years now. As far as changing the tach to 6 cyl, contact Williamsons or one of the other tach repair places for the conversion. Mutt
Do a Goggle search for a 555 timer or a 556 timer. You should be able to get the parts you need for about 10 bucks plus some shipping... If you would like me to order the parts the next time I place a stock order I will mail them and save you the shipping. Al
Alrighty then. Thanks for the insight, Al. I think my search on the 555 is telling me that I can use the digital pulse from the MSD to latch the input on the 555 chip, thereby creating output "clock" pulse the "old school" tach will read....I'd say this is probably EXACTLY what the MSD conversion module does only a lot cheaper. Step 1 complete; a signal my tach will read. Now, how do I get 6 pulses in from the ignition to be 8 pulses out for the tach?? Tach is for eight cylinders, but I am missing two plug wires (250 L6 engine). I'm going back to the sites my 555 search pulled up to investigate, but I get the feeling you might already have that answer !! Jeff
Here's a source for a black box that does conversion for different cylinder counts and different types of ignitions. Hope this helps. Click here: TechnoVersions Website - home of TachMatch
I e-mailed this company to see if this device would trigger early Sun or Stewart Warner Tachs replacing the sender/box.
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