static timing with electronic ignition?

[tr6lover]

hey guys, i have a crane xr700 and was wondering if you can do a static timing with electronic ignition (engine not running) thanks
Randy

 

[TR3driver]

Yes, it can be done, but the procedure varies depending on whether you have an early or late module. The procedure on page 13 of the instructions is basically static timing.

 

[tr6lover]

hi randall, i have an early one i think because the late ones had a led light correct? this was installed on my car whe i bought it and do not have the instruction booklet that came with it......
Randy

 

[70herald]

hey guys, i have a crane xr700 and was wondering if you can do a static timing with electronic ignition (engine not running) thanks
Randy

Why static? is the engine not running at all, no timing light? Anyway, with and earlier type of XR700 the problem is going to be figuring out exactly when it triggers. What I did (this morning!) to set up the XR700 was turn the crank until cyl 1 was aprox 9 degree before TDC. Now move the optical trigger / distributor etc until the spark fires. You could hook up a spark plug directly to the coil but be very careful. The spark will fire at the beginning of the slit, so make sure you are aiming for the correct side of the slit. That extra LED on the newer units made this really simple, however for some reason, I still don't have a spark at all, and the XR700 IS firing.

 

[Adrio]

I have been curious about how this is done. I use points on both my cars but a friend has come by and asked me to time is new (to him) TR3 that had one of these in it. I am sure this is not the last time some one will need to know how this is done.

BTW, I keep an extra plug wire and plug just for this sor to of thing. It come in handy more often then you would imagine. My suggestion is next time you change your ignition wires and plugs, keep the best one of each. Even for the caps that have the wire screwed in I just use the output of the coil for my tests.

 

[TR3driver]

hi randall, i have an early one i think because the late ones had a led light correct? this was installed on my car whe i bought it and do not have the instruction booklet that came with it......
Randy

Poke around on Crane's website, it should still be there somewhere. Or PM me your email addy, & I'll send it to you.
Basically, for the non-LED version, they tell you to hook up the coil with the center wire laying on the rocker cover, and watch for a spark. I believe you could also use a test lamp on the low tension terminals, but haven't tried it myself.

 

[70herald]

I believe you could also use a test lamp on the low tension terminals, but haven't tried it myself.

The low voltage side gets a pulse of several hundred volts, with a low current. You can't just hook it up to a 12 volt test lamp.

 

[TR3driver]

No, that would be the XR3000, which is a CD type unit. The XR700 is still Kettering style.

 

[70herald]

According to the Crane web site both the 700 and 3000 are inductive systems, the difference is in the spark gap (current) and spark duration. "low voltage" is ~400 for either system. BTW, the low voltage on a standard points system hits about 250 volts when the points suddenly disconnect.


Part Number: 700-0231 BACK TO LIST
Primary Voltage Output 400 volts (inductive discharge)
Primary Energy Output 60 millijoules with PS20/40 coil.
Peak Spark Gap 60 milliamps with PS20/40 coil.
Spark Duration 300 microseconds at 6,000 RPM


Part Number: 3000-0231 BACK TO LIST
Primary Voltage Output 400 volts (inductive discharge)
Primary Energy Output 90 millijoules with PS91 coil.
Peak Spark Gap 100 milliamps with PS91 coil.
Spark Duration 2800 microseconds at 2,000 RPM
Dimension 5L x 3W x 1-1/2H, 1-1/2 lbs.

 

[TR3driver]

Interesting. It must have changed then, since the old XR700 was definitely just a switch to ground. It was "inductive discharge", but the ignition coil was the inductor.

And I have an old XR3000, which is definitely capacitive discharge.

 

[70herald]

hey guys, i have a crane xr700 and was wondering if you can do a static timing with electronic ignition (engine not running) thanks
Randy

Thinking about this a bit more, yes. hook up a voltmeter to the "GROUND" side of the coil and ground. When the XR700 sparks, the voltage will jump to 12 volts. When the coil is "charging" ie on what would be "dwell" if you had points, the voltage will be at 0.

A very simple explanation: when the coil is "charging" ie current is flowing, the ground side of the coil is connected to ground so the voltage difference between coil "ground" and ground is 0. When the spark occurs, the "ground" side is disconnected so there will be no current flow across the coil and no voltage loss so the voltage on the ground side will equal the input or 12 volts. A 12 volt light bulb would work just as well.