almost forgot to Post a Pic of my Marquette Oscilloscope ....maxracesoftware wrote: ↑Fri Mar 13, 2020 4:31 pmi also had the Marquette Oscilloscope hooked a few times with Distributor Machine as well as a few times on the DynoDavid Redszus wrote: ↑Fri Mar 13, 2020 2:36 pmNice set up, looks somewhat similar to mine.maxracesoftware wrote: ↑Fri Mar 13, 2020 3:08 am
48 years
my Marquette Distributor Machine ( purchased 1972 ) ... made my own Spark Plug load bar w/adjustable Plug Gaps
what i did was experiment with 5 or so Distributors that would start missing at certain RPMs
adjusted Plug Gaps until Distributor Machine should same RPM as Race Car or Dyno
and its worked great all these years with that Gap ... and correlates within +- 100 RPMs on Dyno
this Pic in 1980's
still works in 2020 ... moved it into Dyno Engine Room years ago .
I have noticed a considerable difference in required firing voltage when firing plugs into a pressure
chamber compared to free air. As the pressure goes up, the voltage requirement does as well and the
spark duration diminishes until misfires occur.
Combining a scope with the distributor machine results in one of the most useful tools in the shop.
With a multi channel scope, various spark plug secondary wires can be tested as well. Some name brands
are not much (if at all) better than OEM wires.
Run the test bench with the shop lights turned off and watch the light show. All that is missing is a guitar.
i wish i would have not sold the Marquette Oscilloscope to a friend
i also back-to-back old Champion Spark Plug checker w/Air pressure Psi -vs- what i was seeing on Dyno + Distributor Machine
played around with modififying Plug ground straps to J-style and J-style pointed end-shapes in 1970's
modified many Distributor single point-plates to for 32oz ? Accel dual-points
used clear distributor caps for more testing
really cool at nite to turn lights off in the Shop and spin a Distributor hooked up to my Spark Plug Load-Board
and watch + hear MSD fire multiple sparks at low to mid RPM then change to lesser multiple sparks at highr RPMs
could spin a Magneto to 9500 RPM , and normal distributors to 11,000 RPMs easily , optional higher HP electric motor
... also cool was smell of Ozone from MSD sparks
i'll Post a Pic of my Marquette Oscilloscope later today or tonite
Sunnen Rod Heater in back , old bath tub converted to Parts cleaner, ideal Block cleaner
bunch of Crankshafts , Jack Stands , Rimac Spring Tester ,etc