zwede said:As part of my upgrade from a Commander 950 EFI system to the Holley HP I decided to run sequential injection. I have a bit of a cam, and a large plenum, short runner single plane manifold. With batch fire (which is all the C950 will do), I'm suspecting there's quite a bit of fuel robbing between cylinders. To avoid a lean miss at low rpm I have to run it rich. Sequential injection where each injector fires individually when the intake valve is open should greatly reduce this problem.
The HP EFI is able to run in true sequential mode, as long as I add a cam sync to my distributor. This is so the HP EFI knows where cylinder #1 is.
My ignition setup consists of an MSD 4x crank trigger, with the C950 ECU triggering an Accel 300 CDI box. The distributor is an MSD 8366 (small cap HEI) with the sensor & module removed.
I bought an MSD 2348 sensor. This is a hall effect sensor that is compatible with the HP EFI and it comes with the magnet.
So here is the starting point. As expensive as the 8366 is, you'd think they could have corrosion protected the reluctor wheel... but no problem, it's going away anyway.
After breaking a tab off the reluctor wheel trying to pull it up, I realized there's a snap ring below the reluctor wheel that holds it in place. After I removed it, the reluctor wheel could be pushed down off the shaft.
I figured out where I wanted the magnet and sensor. For my engine the cam sensor must pulse at 195 degrees BTDC. I rotated the crank to that position and checked where the rotor was pointing. Then I drilled the rotor shaft and bonded the magnet in with JB-Weld. The magnet has a steel collar around it that I dremeled a bit so it conformed to the curve of the shaft.
I then used thin sheet metal to make a collar that wraps around the shaft. I drilled a hole for the magnet.
The collar is spot welded on the other side of the shaft.
The sensor is mounted using a simple L-bracket. I set the air gap to 0.030" (spec is 0.030-0.040).
I hooked the sensor to 12V and the red LED on the back of the sensor lit up. Turning the rotor to the position I marked for 195 degrees BTDC, the light went out.
Finally a picture of the distributor with the cap showing the wire grommet.
I was surprised I wasn't able to find and info/pics of this conversion anywhere.
One thing of note: The MSD 2348 sensor has a little LED on it. When the sensor is powered up the LED is lit. When the magnet is in front of the sensor, the LED goes out. The output wire has the opposite logic, it goes high with the magnet in front of the sensor. So it works like this:
No magnet: LED ON - Output Low
Magnet: LED OFF - Output High
One nice thing about the MSD 2348 is that it will work with a 5V-18V supply voltage, a pretty wide range.
This morning I installed the distributor and checked operation. First I phased the rotor by using an old cap I cut a hole in so I can see #1 terminal. I adjusted the distributor so that the rotor lined up to the terminal with the crank at 30 BTDC.
Next I rotated the crank until the LED went out. This was at 213 dgr BTDC. Still in spec as the spec is 195 +-30, but I wanted it better. I slotted the holes in the bracket sensor making it adjustable and now the light goes out right at 195 BTDC.
bits if related auto wiring
http://garage.grumpysperformance.com/index.php?threads/remote-solenoid-schematic.4846/#post-13266
http://forums.holley.com/showthread.php ... nsor-Setup
summit racing and a few other places sell clear distributor caps which can be useful
http://www.summitracing.com/parts/sum-g5236
YOU May FIND THESE THREADs ALSO USEFUL
viewtopic.php?f=70&t=855&p=25789&hilit=+distributor+selecting#p25789
viewtopic.php?f=70&t=5916&p=18181&hilit=+ignition+coil+plug#p18181
viewtopic.php?f=70&t=1179&p=5875&hilit=ignition+pick+up#p5875
Last edited by a moderator:
