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Six cylinder pMag - flying

Carl Froehlich

Well Known Member
All,

I installed the final production verson of the six cylinder pMag on my old RV-10. I had installed a beta version, it is now replaced with this standard version that is being shipped out to customers.

Installation was very simple. On install you set the timing to whatever you want. For me I decided on MIN timing at 25 degrees BTDC (same as the mag), MAX timing at 34 degrees BTDC. I still have the standard Slick mag on the left side for now.

The plane flew home to Florida yesterday. Preliminary performance indicated measurable gains in effiency. I’ll have better data as we build time but for now some examples:
- 12K’, LOP, 169kts TAS, 2380 RPM, 19.8” MP, 9.6 GPH. CHTs in the 350-360 range.
- 10K’ LOP, 169kts TAS, 10.1 GPH
- 12K’ ROP, 177kts TAS, 12.7 GPH

For this trip the plane was flown solo, with perhaps 150 pounds of cargo.

Carl
 
- 12K’, LOP, 169kts TAS, 2380 RPM, 19.8” MP, 9.6 GPH. CHTs in the 350-360 range.

Carl

First off, congrats on actually getting one of the 6cyl units.

Your perf numbers above are very similar to what I got with the LASAR setup on our RV10.
 
PMAG performance

Do you have any before installation data?

I am hoping your 177kts is a new record for you because my 10 doesn’t go that fast

I am patiently waiting for the 6 cylinder PMAG I ordered.

Thanks
 
Do you have any before installation data?

I am hoping your 177kts is a new record for you because my 10 doesn’t go that fast

I am patiently waiting for the 6 cylinder PMAG I ordered.

Thanks

Here is a data point from the plane a couple of days before install on the trip to VA42 from Florida. Same loading as after install:
9K’, 2380 RPM, LOP 20 degrees, 164kts TAS, 11.3-11.7 GPH

I would assume top end is still around 187kts for this loading, but that is just a data point that means little for how this RV-10 is flown, and does not have much to do with ignition selection. The primary gain with this pMag (or any good EI) is about efficiency. Other pMag aspects like easy starts, auto plugs, no ignition backup batteries and such are bonuses.

Note - this plane was customized for high efficiency cruise (different cowl, difference wheel pants and such).

Carl
 
Are you running high compression pistons?
G

No. Stock IO-540 from Van’s with the Hartzell BA CS prop, also from Van’s.

Injectors have been balanced - GAMI spread is around 0.1 GPH. The only other change from stock is the air box was modified to house the taller K-1000 K&N filter. Modification was simply flipping the air box top plate around and some glass work to make a flange for the SCAT hose that connects to the cowl inlet ring.

Carl
 
I would like to see you do a 4 way GPS box and publish the TRK and GS as well as the displayed TAS.

Also do you have data at the same/similar flight conditions as a before comparison?

Just to remove any errors from the analysis. :)

169KTAS in a -10 LOP is an impressive drag reduction.
 
I would like to see you do a 4 way GPS box and publish the TRK and GS as well as the displayed TAS.

Also do you have data at the same/similar flight conditions as a before comparison?

Just to remove any errors from the analysis. :)

169KTAS in a -10 LOP is an impressive drag reduction.

I only have 90 hours, but have been getting pretty consistent 165 kt cruise LOP (low to mid 10's GPH at 10K & low to mid 9's at 14K). I have EI and balanced injectors, but do not have the James cowl that carl does (don't know what kind of speed increases that is worth). I have done two 4 way GPS tracks to confirm my TAS.

Larry
 
Last edited:
Very cool. Thanks for the posts on performance.

Are the altitudes density altitude? That would take out the temperature and pressure variables.
 
Within the range of practical mixtures (say 0.06 F/A to full rich), any EI with the same timing schedule should net pretty much the same performance.
 
Just to give some more info on the E-mags for the Lycoming 6 cylinders. I installed the updated version about 10 days ago. I removed My left Slick mag with Impulse coupling which was running all my lower plugs. I also changed from aircraft fine wire plugs to iridium fine wire auto plugs. My right ignition is a Lightspeed plasma 3 which runs great and has been on my plane for almost 900hrs and 10 yrs. This change took me about 12-14hrs. Setup And timing was pretty simple. So far I have about 2 hrs time on this setup and so far very happy and glad to replace the Slick. I did change plug heat range from Denso IK27 to NGK 8 or Denso 24 this helped on some test I was performing that were recommended by Brad at Emag. So far performance is better than the Slick when doing test where engine is running on just left ignition. Running as normal there is not much difference than the Slick. EGT’s and CHT’s seem very good in all conditions with the Emag. I think my fuel burn when running LOP at alt 9k is maybe .1-.2 better
With same TAS and cruise settings I always run. Time will tell once I fly a couple
Trips. As of now I will call it about the same.
Overall at this time I am very happy with my change.
FWIW
 
Maybe I've missed something. Are the 6 cyl p-mags available to the average Joe yet? I'm wanting to replace my other mag with something other than a Lightspeed.
 
I ordered my -540 on August 3. I spoke directly with the Lycoming factory around 8/10 to confirm a few details.

Lycoming is currently testing a p-mag but has not approved it for delivery from them.

Current wait time for a Thunderbolt 540 is estimated at 7 months, and the Lyc rep I spoke to thought that by the time mine gets built, a p-mag will have been approved by Lyc, assuming it passes all tests.
 
Maybe I've missed something. Are the 6 cyl p-mags available to the average Joe yet? I'm wanting to replace my other mag with something other than a Lightspeed.

Give them a call and order the pMag. It made a significant and measurable improvement in cruise efficiency in the RV-10.

Carl
 
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