dman535

I would like to be able to program the timing on my HEI much like the timing control elements on the Holley fuel injection systems. Is there a stand alone system out there ? Anyone played around with making a GM ECM work ?

Twin_Turbo

Maybe you can use a GM TBI ECM (speed density). Add the MAP, O2, CTS, knock and TPS sensor, put the TPS on the carb and leave the injector wires off. You can now have the spark controlled by the ECM. Just need an electronic HEI carb.... might work, might not (the ECM might trip code after code because of lean/rich micture problems)

Marck

Monty

MSD Digital 7 Programmable, about $670 + another $100 for the programmer, etc does that. You can actually tune the timing curve for each individual cylinder in 0.1 degree increments. That's much like the high-end aftermarket efi systems, like the FAST I have, Motec, and possibly the Pro level DFI 7 which cost 3x or more. Not a bad deal if you want to get every last hp out of it. I don't know about running a 7 series MSD unit on the street though. Alot of people do, but I don't think MSD recommends it?

Or if you already have an MSD unit, you could add their Ignition Controller, PN 8979. It will plug into you current box and allow individual cylinder spark control, plus all the rev limits, retards, etc. Around $380...


[Modified by Monty, 8:29 PM 1/29/2003]

Ken73

This has been done before. Spark only '7747. The electronic version of the HEI can be had from a junkyard pretty cheap I'm sure.

I think at one point GM had some pickups that used a spark-only controller but I could be mistaken (I seem to remember seeing pickups that had "ESC - Electronic Spark Control" back in the mid 80's?)

I would think if you went that far you'd want to do some sort fuel injection conversion while you were at it.

1979toy

Take a look at MSD part number 8981. That unit will control your advance, and is fully tunable.

Twin_Turbo

Yes, I think the 1984 700R4 equipped C10 came with only a spark controller. Might want to look into that.

dman535

I looked at the MSD stuff and it is many $$ for the whole setup. Am researching the Early 80's ESC angle. Will see what comes of it.