Electronic Ignition/Tach Compatibility

[Mel]

'66 with the 327/300 Chev. motor. I'm thinking of putting on an electronic ignition (EI) setup. A local guy who builds racing engines assures me that, for about $100, I'll have a much better ignition system -- more reliable spark, better advance curve, ... and that it essentially sits inside the distributor cap. He also says I just need a 12v supply. With the 'thermistor' wire from the ignition, I'm getting about 4v to the coil at 'run', 12v on 'start' circuit, as normal. So, a couple of questions:

1. Experience (+/-) with a particular type of EI setup,

2. The tach sending unit is driven by the points. Is the original tach set up compatible with an EI setup?

Thanks.

[Gunslinger]

There are several points replacement electronic systems to fit the Delco distributor in your Avanti. Most cost less than $100. You can get brands like Accel, Pertronix and Mallory come to mind. Pertronix is maybe the best known of them. I don't have personal experience with them but some do say carry a spare set of points in case the module fails...how prevalent that might be is anyone's guess.

The question comes up...why do you feel the need to go away from points if everything is working OK? If it ain't broke, don't fix it. If you want to make the conversion, I would wait until a tune-up was due and necessary. The you can replace spark plugs, wires (if needed) and install the points replacement unit all at once. What many don't tell you is that a points replacement system such as these rarely makes the engine run better...it simply reduces maintenance by eliminating the need to replace points and maybe make spark plugs last a but longer. Timing should not need resetting with no points to wear and dwell change that impacts timing.

Basically, what I'm saying is, if you're happy with how well your engine is running now, why change anything? If you have a specific problem you beed to address, that's one thing.

If you want to know more about them, go to each manufacturer's website and read their install information...it should tell you much of what you need to know, but ignore their big claims for performance increases...you may notice some improvement but not to what they claim.

BTW - any of the electronic points replacement systems don't change the advance curve...that's built into the distributor. It can be changed and improved, by the distributor needs to be removed and put into a distributor machine to accomplish that. Whether operation us by points or electronic, it is a separate function within the distributor. Late model distributors can change the advance curve, but they also require knock sensors installed in the engine block and are computer controlled.

[WayneC]

Basically, what I'm saying is, if you're happy with how well your engine is running now, why change anything? If you have a specific problem you need to address, that's one thing.

I agree, if it ain't broke, don't fix it.

That being said, IMHO the easiest way to switch is to install a Chevy HEI distributor and 8mm spark plug wires, and replace the resistor wire (the feed wire that currently goes to the plus side of the coil) with a normal wire. It's possible there could be firewall interference issues, but I doubt it since Avanti II's were factory-equipped with HEI distributors (starting around 1973 or 1975?).

[BobS]

I think WayneC hit it correctly. The easiest Dissy to drop into your engine is an MSD HEI big cap distributor. It just needs a 12v source that is on in Start and Run positions, has 20 amps or so of power and should be a direct drop in for you Dissy as it has vacuum advance and the coil in the cap. The 12 v source connects to a terminal on the cap and the tach source is right next to the 12 v source terminal. No points nor condensor just pure electronics with an adjustable vacuum advance.

I'll agree with the if it ain't broke don't fix it comment but if you want to upgrade, this is the one. $128 from Summit Racing http://www.summitrac...parts/MSD-8362/

Here's how it sat in my 83, firewall clearance is not an issue. The only problem would be air cleaner clearance if you had one larger than 14" Which would be very uncommon.

I said sat because the engine now has A Holley Avenger HP EFI system on it with the small cap computer controlled HEI dissy. I guess I'm just never satisfied with the status quo.

Bob

Edited November 26, 2010 by BobS