What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Emag ground location

There is also a note that if you are using pin 6 (tach output) to run an additional ground to the efis or instrument.

I am using the left PMag tach signal and that side has a ground to engine case and an additional ground to the efis ground location.

"Adding a ground wire (pin #1 to the EFIS or tach instrument) will help assure a clean signal."
 
Gotcha. But where? The right one I?ll put a ground wire ring on my backup alternator lug. How about the left one?
 
I found the 1/4" studs for the vacuum pad convenient. Each P-MAG grounded to it's own stud.

Bevan
 
Last edited:
Gotcha. But where? The right one I’ll put a ground wire ring on my backup alternator lug. How about the left one?

Put ring terminals on each wire, pick any case bolt thaithat is convenient, sand off the paint where the bolt goes, and torque it to spec, wwhich I can't remember.

You can add additional grounds but DO NOT:
Run both grounds to the same bolt.
Ground them on the firewall.
Connect the grounds together, uunless instructed by a manual of some type.

Send me your email address and I will reply with our EICommander Q&A document.
 
Last edited:
On your 14, is your PMAG configured for the 20 BDC or manually adjusting the TDC to account for the 20 degree timing of the 390 engine?
 
On your 14, is your PMAG configured for the 20 BDC or manually adjusting the TDC to account for the 20 degree timing of the 390 engine?
I have dual PMags on a Superior XP400. I have done some experimenting and collected data (not scientific, but much better than anecdotal). I have also talked with Bill Ross (Superior) and Bill Rapucci (EI Commander). From my results, I am convinced the best setting (at least for my engine) is with the jumpers in place (“A curve”) on the PMag which is slightly advanced from the stock magneto timing of 20 deg BTDC but less than the “B Curve”.
 
Last edited:
There also appears to be a dedicated 1/4" hole through the engine case on the lower left side that will work well for the left emag. Its position mirrors the bolt location that you will likely be using on the right side for your 2AWG ground strap or similar.
Tom.
 
I have dual PMags on a Superior XP400. I have done some experimenting and collected data (not scientific, but much better than anecdotal). I have also talked with Bill Ross (Superior) and Bill Rapucci (EI Commander). From my results, I am convinced the best setting (at least for my engine) is with the jumpers in place (?A curve?) on the PMag which is slightly advanced from the stock magneto timing of 20 deg BTDC but less than the ?B Curve?.

Hi Keith,

Perhaps we are talking apple and oranges. The A curve and B curve are for the amount of advance that the PMAG will advance the timing based on RPM and Manifold pressure. If your engine is timed at TDC and PMAG is configured for a 360 engine, then your base timing starts at 25 BDC and with A curve maxes at about 31 degree or with a B curve it maxes at 37.

The angle valve engine?s base timing which is stamped on the case should be set at 20 BDC, if you are at sea level and cranking, the mags ought to fire at 20 BDC and advances with the same curve, with the jumper in should max to 26 or so. In essence, for an angle valve engine we would need to modify the minimum advance to start at 20 instead of 25 or manually go five degree pass TDC and start the timing procedure.

Now my question has been do you manually adjust for the 5 degree difference or configure the PMAG either with EICommander with the program that Brad has available to set the base at 20 degree and follow the curve based on that?
 
It?s detailed in the install manual. And there is a very good reason to ground it to the engine as per instructions and not the firewall or battery.
Tim Andres
 
So far as the tach goes the G3X shows running a shielded line from the emag to the gea24 with the shield ground terminated only at the G3X side.
 
Now my question has been do you manually adjust for the 5 degree difference or configure the PMAG either with EICommander with the program that Brad has available to set the base at 20 degree and follow the curve based on that?
Hi Bavafa:
Directly to your question, I have not adjusted for the 5 deg difference, and timed to TDC. The quote from Bill Ross was “this is a stroked engine ... the timing just isn’t that important”. And the data I collected seems to bear that out.
 
Back
Top