Electronic ignition on Combat 6 jeeps

[Lachlan]

Hi all,

I haven't been on for a while, but I thought I'd swing by and tell you all about a cool mod you combat 6 drivers (actually anyone running the early Falcon 6 donk) might like to consider. I've long been eyeing an electronic ignition system using a HEI distributor, but not having the funds I haven't bothered to pursue it. But an equivalent (or perhaps better, I don't know) system to use is the electronic spark timing (EST) system used on carburetted crossflow Falcons.

A quick rundown on the system: it senses engine coolant temperature, manifold pressure, RPMs, and throttle position (closed or open, not a proper TPS) and looks up ignition values from a table in the ECU. The whole system and wiring harness can be removed from a donor Falcon (I cut the harness before I realised this, d'oh!) and the sensors all screw in just fine. My beetle already has a Weber carb off a Falcon so I stuck with that, but the EST system will work with any carb - you'll need to fit the throttle position switch under your idle screw. The system is quite sophisticated and includes:

• A start-up procedure where it retards the timing for easier cranking (I think)
• A warm-up procedure which reduces advance until the engine is warm
• An idle condition for when the throttle is closed
• And probably more things that I don't know about... The system is described in detail in the Falcon shop manual, which I don't have.

First impressions are that the engine starts MUCH better from cold (i.e. instant starts, bone-cold, although mine is a bit funny for other reasons), and revs very cleanly. The engine is very responsive at all throttle positions too. Power and economy I don't really know, because mine is nowhere near ready for the road, but the system is a big step up from points ignition and it feels fantastic. Tomorrow I'll throw up some pictures of my setup, a wiring diagram, and a video of it all running as proof.

[GordonB]

Thanks, Lachlan.

I'll be interested to look at this. I am at the stage of putting the cleaned up distributor back on the engine. A few blokes had been talking about converting to an electronic ignition I think, but I wasn't sure exactly how to work it. My engine is the 170ci engine, i.e., pre-crossflow.

Cheers,

Gordon

[Lachlan]

Hi Gordon! Mine's a 170ci as well, and it seems to work really well. I've had three different distributors on mine - the early vacuum type but with the wrong carby, then a later one from a 250ci pre-crossflow, and now the XF system. The XF system was really easy to install - don't chop the wires like I did, because you can use the whole harness, which makes it so much easier. Here's how the system is wired up:



One thing that got me into strife was that six pin plug - I grounded the negative side of the coil by accident (the wire marked 64B on the diagram) and boiled an ignition coil. Aside from that it was all pretty painless. It has a capacitor hooked up to the positive side of the coil too, I guess for noise suppression... I don't know how big it is, 'cause I just took it off the donor engine. Probably a similar size to the one in points distributors.

[JEEPaul]

The 250 pre-crossflow in my Willys Truck has an electronic XF distributor... don't know much about the setup as it was there when I got the vehicle, but it certainly runs well campared with the points type distributors I've had on Falcons in the past.

How'd you go for ignition leads - did to buy the correct lengths with the correct dist cap fittings seperately, or did you find a suitable set? From experience, the XY falcon set doesn't fit the XF distributor, and the leads in the XF set are waaaaay too long as the plugs on the crossflow are on the other side of the head.

[Lachlan]

Ah, I've just remembered that there is one modification you need to make to the distributor - the base that sits on the engine block is funny shaped, i.e. not circular, so the distributor fastener screw won't fit, so you have to grind some of the distributor base down to suit - easy though, I did it with an angle grinder and it took me ~ 10 minutes.

Paul, I just used the XF ignition leads because that's what was there (I only did this on Friday!), but I think Supercheap will have the correct length leads with the right dist cap fittings. When I scratch up some spare cash I'll tidy up the wiring harness and buy the right length spark plug leads. Some blokes in the 'States have made fancy HEI leads for their 6 cylinder Mustangs, so they'll work with our setup, but they're pricey:
http://classicinlines.com/proddetail...od=DUI-200-LWS

[GordonB]

Thanks for that. Lachlan.

This is very timely, and I will share it with the Brains Trust at engine class tonight.

Cheers,

Gordon

[Lachlan]

Unfortunately the video is delayed - I finished processing it on my laptop and then the battery gave out, so it's out of reach until I can find a charger (I left it at Dad's place out of state, d'oh!). Hopefully I'll have it uploaded in the next few days though!

Gordon - awesome!! What did the Brains Trust think?