The definitive Van's Aircraft support community! Buying, building or flying an RV? Join our exclusive family of mentors and enthusiasts!
Our experience with pMags has been pretty much the same as you. Last failure was at 300 feet on takeoff where we suspect one pMag lost it's timing. Thanks to the EI Commander, it was obvious which one had gone flaky.
650 hours on the current RV-8 dual pMag install. No issues and no bad bearings. Total of 20 years on the first RV-8A pMag build - and only last year did one pMag go in for service.
Whatever the redesign was I have the new bearings a couple of times now and they still only last about 500hrs.
I balance my prop almost annually and I don’t have any timing issues, only shaft end play about every 500 hrs on routinely overhauled units that I’ve had since new. I wish I had your luck.
The $550 overhaul price was set by Brad in January 2025. It may cost more than that as things move forward.
somebody should take one apart and document everything inside of it. Maybe its possible to just replace the bearing with something similar. I saw another thread last week that talk about which plug wires and coil you could buy that matched what the P=Mag currently has
Given the rate at which the bearings fail, I would be pretty confident that this is a design flaw (spec'ed a bearing with an inappropriate load rating or no wave washers) vs a cheap bearing issue. Though very likely the bearing is a standard size and, in theory, replaceable by end users. I would be concerned about whether or not there are shims to take up clearance and would need specs in order to reassemble. Given the failure rate, I suspect these are finicky and emag has probably learned some tricks to minimize it. Not knowing them would create challenges for end users on this type of work.
What do you get for the $550 if the SW is up to date which it has not changed in years now. Do they just check for shaft play and run it to make sure it fires OK or do they make any other changes/inspection?
Exactly. My hangar mate used to rebuild Slick mags and Bendix mags at a piper dealer back in the day. He has new bearings for both of those on the shelf. I’d be surprised if the PMag shaft and bearings are not an off the shelf part.
Soooo I opened one up to take a peek. A solid state circuit board. A stator, a sealed coil pack, and a steel shaft. There hasn’t been a software update in years. Just like I keep saying, $550 plus shipping for a (likely off the shelf) bearing replacement on a poor design, not cool.
Did you happen to see what bearings it uses? Both of mine are on my plane but the next time they have end play I’ll probably try to replace on my own.
Unfortunately not. It is a friends and didn’t want to take a chance of bricking it. There is a brass bushing on the inside, looks like it is held in by a pin or small Allen. Looks like it is just for positioning the shaft. There is some tamper marks on the 4 screws holding the stator to the case. Bearing looks like it comes out from the engine side after removing the gear.
Boy, i sure hope they are not using a bushing in that application. There should have been two bearings in there somewhere. Shame on them if they used one bearing and one bushing.
there is another thread on the Pmag connector. https://vansairforce.net/threads/4cyl-pmag-connector.231911/#post-1885873
ETCO DT-1000-HB terminal per that thread posted above in #22.
I would also like to have some of the DT-1000-HB terminals if we could get a group buy together
And so it begins.
I sent mine in before Thanksgiving and received them 2 weeks later. I was expecting the upgraded bearing stack, but I suspect that is a special request? My understanding is that it was standard practice to upgrade the stack when EMag Air performed the overhaul service. My other understanding is the upgraded stack comes with a different aft housing, but I haven’t confirmed this with Hartzell/QAA.
Says they've been doing the upgraded bearing since 2022 in the manual on Emag website
Yes, exactly right for me at least. The spark plug connection on the emag wires doesn't give much tactile feedback suggesting good attachment to the plug. The MSD on the other hand does. The MSD cables and boots just appear to be a better product all around.
Really no need if have the sensor on both the mag and pmag, if the mag is turning, you'll have a tach readout.
I sent mine in back in November, it was 2 weeks. If they need to replace your circuit board(s) for any reason, it sounds like those are back ordered and could substantially delay service.
Firmware V55 applies to the Series 200 6-cylinder P-mags, correct? For the Series 114 4-cylinder P-mags, I think the current firmware version is 41, maybe a little higher.
Correct, series 200 6 cylinder pMags.
That’s great news. Checked receipts, and Rhonda Barrett sent the P Mags on our -7 in for service late 2023.
Well I just pulled one of my e-mags from my IO-360 angle valve after noticing erratic idle after hearing about the radial play in the shaft . . . there shouldn't be any, period! I measured the radial play and it is .005 which is unacceptable. I have about 450 hrs. on both of them and have used 20W-50 Mult viscosity Aeroshell and Exxon Elite prior to it. I also do oil analysis ever since it was new and never had an unacceptable result.
Yes, everyone seems to tell you these things are great and reliable, yet every week we hear another story of failed bearings. If you look to move away, the sds cpi is a much better option with no moving parts to under engineer and fail.
I recommend calling QAA out in Tulsa to get a better time estimate for how long to repair your pmag. I sent both of mine in just before Christmas. They didn’t open them up until after New Year’s and I got them back the first week of this month. I was initially told to expect a much longer delay if the circuit boards needed replacement or updating, but fortunately mine didn’t. They were upgraded to the new bearing stack, but the housing looks the same.
Agree 100%, I’m convinced that most folks consider the ease of installation of the pmag the deciding factor to install it.
I spoke with QAA and they are out parts until the end of March
The ETCO part number DT1000-HB are available from Tons Performance as their part # ST-LS-L Coil Connector for $.72 Each.
