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Pmags in the heat. Or slicks

L

Lowleveldevil

MEMBER
I have no experience with Pmags or Electronic Ignition . I am concerned with this blast tube cooling as I run in very hot and cold conditions . Also can you hand swing to start with Electonic ignition. Any suggestions appreciated. I would prefer Mags but have issues fitting .
 
What is very hot? I fly in the summer in SE georgia and I have no problems with my PMAGS.
 
Hell, I live in Alaska and I have blast tubes on my Pmags. It's the standard installation and seems to have resolved early installation heat failures. You might prefer Lightspeed or EFII. I've considered switching to EFII's newest ignition but I have better things to chase first.

I heard a story about Pmags not starting with low battery but the story is that the starter seems to pull too much current and the Pmags won't fire, but they fire perfectly with a flick of the prop by hand. I'm glad to have heard about it before I experienced it on my own.
 
Blast tubes are super easy to install. I’ll find some pictures of mine and post them up here in a minute. I’ve had zero pmag issues in Alabama.

And you can hand prop as long as you have power applied to the pmags. I’ve heard of some folks using a 9v battery to do that but don’t have any experience with it.

EDIT: added pics

The first two show the tube inlets at the top. Just a 1” aluminum flange, around $9 each.

Then a couple of lengths of 1” SCAT, around $5 per foot. I think I used 2 or 2.5 feet total.

Secured with zip ties and safety wire.

aed52737288e3f3c338bc5187c869649.jpg


3b83a55f9c1b1820ea604ff6f01384f6.jpg


6e4ec6a7072c51342cde5096e896045d.jpg
 
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For those of us with (small) alternators, batteries, no starters, but with dual slick/bendix mags, my wiring is pretty straight forward.

Anyone have any diagrams showing how one might power a p-mag off the battery but not off the master so it is not being powered full time? I believe p-mags will self-excite after a certain low(?) RPM, so is it as simple as wiring a completely separate mag bus that comes directly off the battery, then turning it off after startup? I hand prop with the master off and don't bring the avionics alive until ready to taxi, but would need to excite the mag enough to let me hand-prop...
 
motosix said:
For those of us with (small) alternators, batteries, no starters, but with dual slick/bendix mags, my wiring is pretty straight forward.

Anyone have any diagrams showing how one might power a p-mag off the battery but not off the master so it is not being powered full time? I believe p-mags will self-excite after a certain low(?) RPM, so is it as simple as wiring a completely separate mag bus that comes directly off the battery, then turning it off after startup? I hand prop with the master off and don't bring the avionics alive until ready to taxi, but would need to excite the mag enough to let me hand-prop...
Click to expand...

My understanding is that once the pmags reach a self-powering state, they stop drawing from ship power automatically.

A call to the Emagair could explain better: https://emagair.com/contact-us/
 
motosix said:
For those of us with (small) alternators, batteries, no starters, but with dual slick/bendix mags, my wiring is pretty straight forward.

Anyone have any diagrams showing how one might power a p-mag off the battery but not off the master so it is not being powered full time? I believe p-mags will self-excite after a certain low(?) RPM, so is it as simple as wiring a completely separate mag bus that comes directly off the battery, then turning it off after startup? I hand prop with the master off and don't bring the avionics alive until ready to taxi, but would need to excite the mag enough to let me hand-prop...
Click to expand...

Experimental=experiment. It should be simple to
do.
 
motosix said:
For those of us with (small) alternators, batteries, no starters, but with dual slick/bendix mags, my wiring is pretty straight forward.

Anyone have any diagrams showing how one might power a p-mag off the battery but not off the master so it is not being powered full time? I believe p-mags will self-excite after a certain low(?) RPM, so is it as simple as wiring a completely separate mag bus that comes directly off the battery, then turning it off after startup? I hand prop with the master off and don't bring the avionics alive until ready to taxi, but would need to excite the mag enough to let me hand-prop...
Click to expand...
The self energizing rpm is too high to keep the engine running in your scenario. The installation instructions describe how to wire in a separate 9 volt battery for hand starting.
 
motosix said:
These require a flywheel to allow crank position triggering via magnets.
Click to expand...

My comment was for Lowlevel. Do you have an alternator? If so, you could use TCW IBBS backup battery system to power a Pmag when the master was off. Or you could do the same with a non-mechanical electronic ignition and have start current as well as backup battery.
 
stewartb said:
My comment was for Lowlevel. Do you have an alternator? If so, you could use TCW IBBS backup battery system to power a Pmag when the master was off. Or you could do the same with a non-mechanical electronic ignition and have start current as well as backup battery.
Click to expand...

That was the crux of my initial question: I was curious what the 9volt battery (or backup battery) circuit looks like for pmag initial power. It sounds like an example of that circuit may be found in the installation manual for the pmags, so I will see what Google can turn up there.

To answer your question: I do have a small 8AMP B&C alternator which is plenty for my current draw, and my EarthX is way more battery than I actually need since it doesn't drive a starter. It is now an extremely simple electrical system which was the goal (not even a key switch for the mags; just two toggles), but I can't deny the potential upsides to p-mags hence my interest in this thread.
 
motosix said:
That was the crux of my initial question: I was curious what the 9volt battery (or backup battery) circuit looks like for pmag initial power. It sounds like an example of that circuit may be found in the installation manual for the pmags, so I will see what Google can turn up there.

To answer your question: I do have a small 8AMP B&C alternator which is plenty for my current draw, and my EarthX is way more battery than I actually need since it doesn't drive a starter. It is now an extremely simple electrical system which was the goal (not even a key switch for the mags; just two toggles), but I can't deny the potential upsides to p-mags hence my interest in this thread.
Click to expand...

How big is your earthx? Mine has no issues turning a starter. Or running pmags at low rpm.
 
CamTom12 said:
How big is your earthx? Mine has no issues turning a starter. Or running pmags at low rpm.
Click to expand...

When I had a starter, I could damn near taxi on the EarthX alone. If I pulled the spark plugs, I might even have been able to get up into ground effect before smoking the starter. These batteries are pretty amazing.

So, I don't actually believe I need a 9Volt battery since I have some many amp/hours in the EarthX. I was initially just hoping for a diagram out of curiosity. Your info was helpful.
 
motosix said:
So, I don't actually believe I need a 9Volt battery since I have some many amp/hours in the EarthX. I was initially just hoping for a diagram out of curiosity. Your info was helpful.
Click to expand...
Where is your EarthX located? How long will the wire be between the battery and your new Pmag switch? That wire will always be hot which defeats the primary purpose of a battery master switch. It might be a good idea to place a fuse or C/B at the battery in this new circuit similar to the original PA-18 system.
 
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