Distributor Testing
Posted: Mon Jun 18, 2012 1:09 pm
Because so many engines Neil Bainbridge was getting in to test on his dyno had distributor problems, Neil has invested in a distributor testing rig.
It's a great piece of kit which allows him to run all sorts of tests to correctly set the dizzy and optimise it's performance.
With points distributors you can set the phasing correctly for the number of cylinders, plot the advance and dwell curves and from them see if you
have points bounce or a worn cam for instance and fluctuations in the dwell through the rev range can show up worn bearings. Twin spark dizzy's
with 4 set's of points, 2 for each bank become a lot easier to set up as you can see exactly what each set is doing. You can also see how the
operation of the bob weights works, the graphs will show if they are sticking or need lubricating as well as reading the exact amount of advance.
With the Porsche wiring harness you can unplug it from the car and take in your hole system of dizzy, coil and cdi box for testing in unison, which
eliminates any problems in the whole system which is useful. With a performance engine it's also a little less stressful on the motor to be able to
set up the distributor advance on the machine rather than running the engine at 8000 rpm in the car while you wave your timing light around!
Here's Neil working on the advance curve for mine the other night, it's an electronic system from Pertronics so we're checking the phasing between
the twin pick ups as well. At the moment it's showing 13 degrees of advance in the distributor at 8000 rpm which equates to 26 crankshaft degrees,
so by dialing in 4 degrees of advance at idle will achieve the 30 degrees of advance we're aiming for.
Remember that the distributor is running half the speed of the crank. With the cap on you can test the firing order for example as it might not be
quite as written on the cap itself
also with it running into a spark plug, you can physically check it's sparking through the entire rev range.
Hope that's of interest.
It's a great piece of kit which allows him to run all sorts of tests to correctly set the dizzy and optimise it's performance.
With points distributors you can set the phasing correctly for the number of cylinders, plot the advance and dwell curves and from them see if you
have points bounce or a worn cam for instance and fluctuations in the dwell through the rev range can show up worn bearings. Twin spark dizzy's
with 4 set's of points, 2 for each bank become a lot easier to set up as you can see exactly what each set is doing. You can also see how the
operation of the bob weights works, the graphs will show if they are sticking or need lubricating as well as reading the exact amount of advance.
With the Porsche wiring harness you can unplug it from the car and take in your hole system of dizzy, coil and cdi box for testing in unison, which
eliminates any problems in the whole system which is useful. With a performance engine it's also a little less stressful on the motor to be able to
set up the distributor advance on the machine rather than running the engine at 8000 rpm in the car while you wave your timing light around!
Here's Neil working on the advance curve for mine the other night, it's an electronic system from Pertronics so we're checking the phasing between
the twin pick ups as well. At the moment it's showing 13 degrees of advance in the distributor at 8000 rpm which equates to 26 crankshaft degrees,
so by dialing in 4 degrees of advance at idle will achieve the 30 degrees of advance we're aiming for.
Remember that the distributor is running half the speed of the crank. With the cap on you can test the firing order for example as it might not be
quite as written on the cap itself
also with it running into a spark plug, you can physically check it's sparking through the entire rev range.Hope that's of interest.
