Electronic Dizzy ?

[whollsee]

Originally Posted by Dom

....I've heard many different things about the upgrade. One thing I'd be interested in knowing - can you still run your OEM tacho with the HEI dizzy? If I understand it right (probably not!)...

Yes it does run and it is easy az to wire up. Just can't remember how I did it. I'll check when I get a chance. I do know that I ran a wire with inline fuse direct from dizzy power terminal through firewall and patched into the oem tach wiring which is in the ignition chain. That juices the dizzy and runs the oem tach [induction type I think - measures draw]. The tach line/terminal on the dizzy I only use for handheld tuning tach.


These are a great upgrade Gildo. No going back. This combined with my weber [which I think you have also] makes a huge difference. Couple of issues to watch for...they can suck oil up the shaft into the top. Fix is to block all but one the breather holes above gear with a bit of rtv. Also the bush and shims between shaft and gear can wear/disintegrate quickly on a long km drive. This causes the rotor to rise into top of cap and the tip rips off/melts down...messy. Worth checking to see if you think the setup as supplied will hold up before you install. Easy to replace with something a bit more bullet- proof.

[360]

i use about 100L per 300+k's around town and 400+ k's hwy!!
and i have one of those new hei chev type dizzy's runs great..

Originally Posted by ROK360

Alexander, Yeah mate the Wagon had the standard motorcraft dizzy with the electronic ignition.

Now that the wagon is being used as a daily driver I am even more impressed with the HEI - improved starts, power and economy (if you can say economy and AMC 360 in the same sentence.) Averaging about 270kms from 53L LPG (last two weeks) - using a little bit of PULP for starts and warm up. A tank of PULP should last about 2 months.

[Dom]

Originally Posted by alexander

hi dom and gildo.. i am not saying your wrong about the jeep setup, as i dont know specifically about that, but i can say that most tachometers dont work like that. the old smiths tachometer in my car (ie circa 1970) did work with a coil in the ignition circuit and wont work from with electronic distributors. but more modern (ie 70s onward) tachometers sense the voltage pulse and dont require significant current to drive them. so there is a good chance that this will work fine.

regards
alexander.

Al,

I'd be thinking your Smiths tach would be the tachogenerator type, driven directly by the energy produced in that coil. The Poms did things that way in aircraft and cars for ages. I collect instruments and have a dozen or so examples sitting in my shed - but couldn't say without seeing that particular one.

I think ROK360 is on the right track, he's said it better than me. The tach will work, it still just sits in series with the whole ignition circuit (between the 'run' terminal on the ignition switch and the works in the HEI dizzy) detecting current pulses. It works the same way it always did.

My comments were correct - ithe tach is deliberately designed as a low impedance device so there's no voltage drop incurred in the ignition circuit by inserting the tach.

You can see this in the stock CJ wiring loom - if the tach isn't fitted, the plugs in the loom for connecting to the tach are designed to plug into each other instead, so that the ignition circuit is not broken. It is in a series circuit with the whole shebang, as an ammeter would be in a DC circuit. Try plugging any ammeter directly across a 12V power supply - or to a tach output line from an electronic ignition - and you'd smoke it.

[Gildo]

Yeah My CJ has the webber up grade, and my YJ has the webber and an Omni Magnum set up.
Ive been trying to track down any info on how or why the Omni even works, it looks like a big anodised heatsink with a clear potted board on one end, very 80s movie "spaceage" design and hooks between the coil and the dizzy.
No longer produced and the company appears to have been absorbed by a bigger auto parts conglomorate.

Any idea if this will work with or against the HEI dizzy???
Will I be just installing 2 HEI systems in series??