[Michael Burbidge]

I'm replacing one of my slick mags with a p-mag. I have basic Van's CHT and EGT gauge on #3 cylinder. I lean to rough and richen a little. Will I still be able to lean to rough with a p-mag? I'm not planning on upgrading my instrumentation.

Should I be rethinking my p-mag decision some given my instrumentation.

What do you think? Does anyone else run p-mags with basic instrumentation?

Thanks,
Michael-

 

[Kyle Boatright]

I ran a Pmag for some time in my RV-6 which has J-3 instrumentation. You should be fine.

 

[Toobuilder]

The only difference that you might see is that it takes a lot more leaning to get to "rough".

 

[Mark Albery]

My set-up is similar to yours. No problem and I concur you can lean quite a bit more before it goes rough.

In fact the cylinder on the EGT gauge goes a fair bit lean of peak. No idea about the other cylinders of course!

 

[Larry DeCamp]

pmags lean

I have two Pmags with carb 0320. It will lean to about 1350 F with 150F spread. Of course, YMMV due to EGT position/calibration.

 

[Toobuilder]

Larry, I'm guessing that 1350 is well on the other side of the hill? The -8 starts to stumble around 1350 as well, but that is WAY (125) past peak with this airplane.

 

[Michael Burbidge]

Thanks

Thanks for the responses. Sounds like I'll be good with my basic instrumentation.

My slicks are coming up on their 500 hour inspection, so I'm going to replace them one at a time over the next few months, with p-mags.

Michael-

 

[N941WR]

Make sure to install them exactly per the instructions (including grounding them to separate case bolts) and to put each P-mag on independent pullable breakers.

 

[Larry DeCamp]

Bill R question

Why pullable breaker? I have my Pmags on separate 5 amp fuses per B$C schematics.

 

[N941WR]

Why pullable breaker? I have my Pmags on separate 5 amp fuses per B$C schematics.

If wired per the Emag recommendation, you can drop power to them to test their internal generators. I had one go bad at 500 hours and the ignition never skipped a beat. The only way I knew it was to pull the power during my preflight.

 

[GalinHdz]

Why pullable breaker? I have my Pmags on separate 5 amp fuses per B$C schematics.

Yes you can use separate 5A fuses but if you do I highly recommend including a momentary OFF push button switch for each P-Mag to test them before flight. Something like any of these:

http://www.ace4parts.com/Products/M...A-at-125V-(Off)-On-Black-Button__30-2299.aspx

http://www.ace4parts.com/Products/Push-Button-SPST-6A-at-120V-On-(Off)-Red-Butt__30-458.aspx

http://www.ace4parts.com/Products/Square-Snap-in-PB-SPST-3A-at-125V-On-(Off)-Red-Butt__30-10070.aspx

 

[N941WR]

Yes you can use separate 5A fuses but if you do I highly recommend including a momentary OFF push button switch for each P-Mag to test them before flight. Something like any of these:

http://www.ace4parts.com/Products/M...A-at-125V-(Off)-On-Black-Button__30-2299.aspx

http://www.ace4parts.com/Products/Push-Button-SPST-6A-at-120V-On-(Off)-Red-Butt__30-458.aspx

http://www.ace4parts.com/Products/Square-Snap-in-PB-SPST-3A-at-125V-On-(Off)-Red-Butt__30-10070.aspx

The problem with these switches is they are known to fail but it really doesn't matter as long as they are on independent circuits and you can test the power independently.

 

[Bevan]

Why pullable breaker? I have my Pmags on separate 5 amp fuses per B$C schematics.

If using fuses, I seem to recall that Emagair says to use slow-blo fuses. Breakers are already slow when compared to a fuse. I could not find slow-blo-ATC style fuses.

Also, You do need someway to power p-mags up/down for testing/timing independant of the P-lead switch. The sequence is important.

I ended up with switches AND pullable breakers.

All above info from my memory which is getting older...just read the manufacture's instructions carefully.

Bevan

 

[RFazio]

I've got dual P-Mags

I put dual non pull able breakers. If I want to test the generator in the pmag I just hit the master. Power off to the mags, she still runs, I'm good to go.

 

[Jesse]

I just use a switching breaker for my Pmag. To start the plane, Master and Pmag go on. During runup, I kill the Pmag switch and do my Mag check.

 

[N941WR]

I just use a switching breaker for my Pmag. To start the plane, Master and Pmag go on. During runup, I kill the Pmag switch and do my Mag check.

I'm confused, do you also have a P lead switch to ground them?

 

[GalinHdz]

The problem with these switches is they are known to fail but it really doesn't matter as long as they are on independent circuits and you can test the power independently.

ALL switches are known to fail but as you well stated "it really doesn't matter as long as they are on independent circuits and you can test the power independently". Better to have a method for testing than no method at all.

 

[GalinHdz]

I just use a switching breaker for my Pmag. To start the plane, Master and Pmag go on. During runup, I kill the Pmag switch and do my Mag check.

I'm confused, do you also have a P lead switch to ground them?

Probably something similar to one of these:
http://www.aircraftspruce.com/catalog/elpages/pbcircuitbrkr2.php
http://www.aircraftspruce.com/catalog/elpages/circuitbreakers.php

 

[N941WR]

In my installation, I used pullable breakers but have a Threeway switch to perform the preflight test (No power & grounded, no power & ungrounded, powered & ungrounded).

This setup required an additional switch to power the P-mags for setting the timing. I used a small stereo plug for this extra switch. See the electrical page of my website, for details.