Hi Gents,

I have a -hopefully- very simple question about the ignition/distributor of my 72CS 350 cui.
I recently installed pertronix ignitor and replaced the points. In the end, this is for me just a 50% solution as mechanical and vaccum advance remain. There are solutions like 123ignition with internal knock sensors which replace complete all vacuum/mechanical advance systems; but here I can just get them mostly for british cars.
I read a lot here about HEI conversions, but I am not sure if it is the same.
When I take a look to ready-to-built-in distributors like MSD, they still have mechanical/vacuum advance on board.
So my question in simple words ? Is there a way install a complete electronic system ? If so, who is the manufacturer ?

Thanks a lot !

Regards,

Marc

 

HEI just replaces the points with an electronic trigger, and puts the coil in the cap away from engine heat. There's no discernible difference between what you have and an HEI. Some folks here have had bad experiences with Pertronix units. I have a Pertronix I that ran perfectly for more than 10 years, and two Pertronix III units that were unreliable out of the box.

Several complete fuel injection systems also include spark control. That's probably more than you want.

I'm using an MSD Programmable 6AL-2 (#6530). That has programmable RPM and Vacuum ignition retard, and it comes with a MAP sensor. You need to use a distributor to trigger it - your pertronix should work as a trigger - and lock out the mechanical and vacuum advance on the distributor. Or you can get a fancy distributor from any vendor that has lock outs and better triggers.
Also recommend using an external coil, a small body distributor (non HEI), an MSD Cap-a-dapt (converts small body distributor to a Ford HEI style large cap) and an adjustable MSD rotor.

This kind of setup has several drawbacks:
1) The retard is 100% electronic, but the distributor is still mechanical. This means you can only advance/retard about 24 degrees and still get a reliable spark. More than that and the rotor doesn't line up with the cap terminal! Normal distributors actually move the rotor for the mechanical advance to keep it aligned. A traditional distributor can provide around 36 degrees (or more) of advance total.
2) You need a large cap so there's more distance between the terminals to reduce the risk of cross fire.
3) Expensive, and it is a little more wiring than a normal MSD box.
4) Several folks here will say it's a waste of time and money. I agree- IF you can get a distributor to run just the way you want. I simply never could get a stable mechanical advance curve even going through a half dozen advance kits, and three distributors.
5) You have to use a computer. Hey, some guys here hate using computers!

Advantages:
1) 100% computer controlled, tunable on the fly
2) Tune from your seat, not bent over the fender
3) Steady timing at all RPM ranges - I always had "bouncy" timing below 1,200 RPM
4) No time spent futzing with springs, weights, and adjusting vacuum cans.
5) Vacuum advance can be very precisely located - drive around with a vacuum gauge, see where cruise vacuum sits, lay in your retard curve based on that.
6) The normal MSD features - RPM limit, boost/nitrous retard, start retard, multi-spark magic, etc.

We had a bit of discussion over at ROP about this box:
http://realoldspower.prophpbb.com/topic9581.html

For my build - a spirited daily driver 403 - it was the right choice. I went through two pertronix units and an accel unit and wasn't really happy. This particular build loves lots of initial timing, but also pings easily, so really precise timing control is important.

My build:
http://realoldspower.prophpbb.com/post48782.html

 

It sounds like your question is about a fully computer-controlled distributor. This is exactly what Olds did on the CCC 307 motors. The distributor has no vacuum or mechanical advance. The computer uses the throttle position sensor, MAP sensor, BARO sensor, and coolant temp sensor to implement ignition advance electronically. There is a "limp home" advance curve built into the module in the distributor in case the computer fails. It provides significantly reduced power (which is really saying something on a 307...).

The CCC distributor bolts into and 1964-1990 Olds V8, but obviously you'd also need all the other sensors and a computer with a custom advance curve for your motor. Alternately, MSD and others sell aftermarket systems like this.

 

The aftermarket offers a distributor in which the vac and centrifugal settings are electronic and are adjusted with a pot on the distributor. Go to MSDs site and look at the Digital E-Curve distributor. Not 100% sure on Olds applications. Call em and ask.

 

Not available for Olds.

 

Thank all of you very much for the detailed answers, highly appreciated.
I think I stay wit the Pertronix....thanks @ll, this is still one of the best forums in my opinions.

 

I talked to a guy this past summer that had a Mallory unit like that on his ford.

Idk if they make one for olds but it sure looked nice

 

Call the MSD and Mallory tech lines and ask. For the not-so-popular lines they may be available just not advertised. I dont see why someone couldn't simply modify a CCW rotational dist to fit into a Olds housing. Cut the shaft, pin an Olds gear to it, bush the housing etc... Sounds simple enough. I thought someone was doing this Maybe Bill at BTR Performance?

http://www.btrperformance.com/

 

If you want to get your hands dirty, you can use a CCC distributor and module and a '7747 ECU from a TBI Chevy truck. Reprogram the PROM to only control the advance curve. Of course, you'll need to add a TPS and MAP sensor, but there are PROM emulators that let you change the spark map on the fly from a laptop. Once you have the best curve, burn a PROM. Moates sells the emulator hardware and software.