FE-FC Holden Discussion Forum

I’m looking to get hold of both a grey motor and red motor cam. I’m after ones that are old, manky and fit for the scrap bin. The bit that I am interested in is the distributor drive gear, and the 4-6” of cam on one side of the gear. Happy to pay postage, but hoping to get a junk cam for free.

For the curious, I will take the drive gear, and machine down the 4-6” of cam to make a shank that that will fit into a drill chuck. I will fit the shank into a right-angle driver, and put the driver onto my drill press. This will give me a drive gear running horizontally. I’ll jig up a grey (or red) motor dizzy so that I end up with my drill press running the dizzy in the normal vertical position.

Now here’s where the fun starts  8).

I’m going to do some testing on early Holden ignition systems, and compare them against each other under load. So far the lists of testes are:
a)   standard Holden grey motor Kettering ignition system (either Bosch or Lucas) – distributor and coil. Mechanical advance only.
b)   standard Holden grey motor Kettering ignition system with coil replaced by a Bosch GT40 coil.
c)   Scintilla Vertex NV6 magneto with fixed advance.
d)   Scintilla Vertex NV6 magneto with mechanical advance.
e)   Red motor Scorcher ignition – standard Holden coil.
f)   Petronix Ignitor I (model 1864A) electronic ignition system – standard Holden coil.
g)   Petronix Ignitor I (model 1864A) electronic ignition system with Petronix Flamethrower 40,000V coil (3Ω, 12V part number 5903: 40501 for chrome or  5905: 40511 for black).
h)   Mallory Double-Life model YC476HP dual point distributor – standard Holden coil.

By changing the drill-press belt configuration between tests, the drill press allows for the following speeds (remember that dizzy speed is half crankshaft speed):
Distributor   Crankshaft
160   320
195   390
290   580
310   620
420   840
470   940
490   980
610   1220
680   1360
740   1480
765   1530
1490   2980
1550   3100
2350   4700
2410   4820
3645   7290

12V power supply is taken from a standard car battery. The secondary ignition system is connected to six spark plugs mounted in a metal rack, earthed back to the battery. Spark plug gap is going to need to be a bit bigger than standard – I’ll use the values in the Vertex overhaul manual. Distributor speed is monitored by a hand-held digital tachometer. Coil temperature is monitored via a hand-held infrared thermometer.

Now for the cool bit. I managed to lay my hands on an oscilloscope (with many thanks to the gentleman who sorted it out). The kids think I’m setting up a secret lab. This will measure some 0-600V and 4-10A on the primary side. I’m looking for peak voltage as a reflection of primary circuit capacity (higher voltage = more ability to provide higher voltage in secondary circuit). Also looking for evidence of lower primary voltage at higher distributor speeds (insufficient coil charge time). Tests to be conducted over a period of time until coil temperature stabilises, and both initial and final test values compared to evidence the effect of heat soak and increased primary winding resistance.

I need to do some more homework, but with some jiggery pokery I should also be able to measure the secondary side (60kV and 10-100mA). I really want to measure the secondary current too. Looking for peak voltage as an indicator of the ability of the secondary circuit to ionise “difficult” air/fuel mixtures. Looking to measure spark duration as opinions vary as to whether a long or short spark is better. Looking to calculate ignition energy (volts x amps x time) as a measure of the overall energy put into the air/fuel mix.

This is no rush project, and I still have a lot of electronics learning to do… should be fun though.

Cheers,
Dr FrankenHarv.

Harv, got a couple of grey cams still in old motors you are welcome to.
Jim

Harv  sounds like you need an old dissy graph machine there were some go through a Taft auction last year where I bought my Mazak Lathe from  all 2 tone of her ....They still send me the listings every time they have a Taft auction will keep an eye out for you as they have a variable  speed control to check the advance curve  .....FC427.....

Thanks Jim - appreciated. Let me know a time that suits and I'll pick it up (no rush at all - long term project).

I'd love a regraphing machine... one of the gentleman on the FX/FJ forum built one, which had me thinking about doing the same (then again, I wanted to build a home-made flowbench too). His was setup just to measure advance - the motor spun the dizzy, a plate rotated with it to show the position of the rotor, and the plate was read with a timing light. Do the original Vane-type machines just measure advance, or do they measure volts/amps too?

Cheers,
Harv

All sorted.

Some interesting results.

One of the gentlemen from the FB/EK forum dropped of a grungy red motor cam this week. Out of curiosity, I measured up the red motor distributor drive gear, and compared it to the grey motor cam one (I used the cam that is destined to go into my Norman-blown meth monster project). The gear is near identical on both cams - 1.74" diameter, 13 teeth and 60 degree helix angle. The only difference is that the red motor gear is wider - 0.615" compared to the grey at 0.515".

Looks like I will be able to use the red motor cam for both red and grey motor dizzy testing (many thanks for the offer though Jim).

Cheers,
Harv