VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #41  
Old 06-10-2022, 04:10 PM
jbDC9 jbDC9 is offline
 
Join Date: Jan 2005
Location: Houston, TX
Posts: 938
Default

Quote:
Originally Posted by GOFT View Post
I am not to keen to try hand propping an O-390.
A C-65 perhaps.
Thread drift; I hand propped an IO-520 on a Baron 58 once. Just once. Was the easiest hand prop Iíve ever done, and I suspect that was all luck. I certainly wouldnít want to try it again.
__________________
John Bixby
RV-8 QB sn 82030 - 1st flight Nov 2006
O-360-A1D/CS prop/Pmags
1875 hrs
Houston, TX
Reply With Quote
  #42  
Old 06-10-2022, 04:10 PM
Walt's Avatar
Walt Walt is offline
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 6,717
Default

Don't get me wrong, I think Brad and the others at EMAG do a great job and provide excellent service, a model company in that regard.
I just think some of the touted advantages as compared to mags are somewhat exaggerated, lately I've sent back a number of units for bearing changes which ends up costing around a kilo buck (for 2 units) with service cost and labor for customers. I've also had to spend quite a bit of time correcting/repairing bad wiring/installations at the less-than-ideal connector they use.
Are the advantages worth it, for some folks perhaps it is, for me, not so much.
__________________
Walt Aronow, DFW, TX (52F)

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 2000+ hrs, New Titan IO-370, Bendix Mags, MTV-9 prop
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
Reply With Quote
  #43  
Old 06-10-2022, 06:52 PM
jcarne's Avatar
jcarne jcarne is offline
 
Join Date: Jul 2016
Location: Worland, Wyoming
Posts: 2,291
Default

Quote:
Originally Posted by Bavafa View Post
Carl is not alone, I often get it started in one blade as well when cold engine. About 2 seconds of the boost pump is the right amount to get it started that way.Over priming usually causes more cranking for me.
I talked to Carl on the phone and have a subtle change Iím going to try. I think I am getting too much fuel often times. Sorry for the thread drift guys.
__________________
Jereme Carne
PPL
RV-7A Flying as of 03/2021
Reply With Quote
  #44  
Old 06-14-2022, 02:07 PM
DCBrown198 DCBrown198 is online now
 
Join Date: Mar 2018
Location: Dallas
Posts: 29
Default

Away from home I had one 6-cylinder PMAG internal alternator fail at 45 hours. Unit still provided excellent ignition for start, and flight. Had I developed a dead electrical system then that one PMAG would have died. I have two...so the redundancy was acceptable for the flight home. Emag promptly repaired the unit at no charge.

RV-10 builders take note. If you have your aircraft battery(s) in the rear as the plans call for, and you pull your bus power from the battery side of the starter contactor at the firewall, as the Van's generic electrical system describes, you may have starting problems with the PMAGs.

This is rooted in the voltage drop seem at the starter contactor as the starter is pushing the engine thru each compression stroke. Turns out that the voltage drop at the upper stage of each cylinder compression (right before the PMAG fires during start) is just enough to affect the PMAG and it may not send a spark at TC. After much frustration and trying to figure out why my engine would not start I was informed of this RV-10 issue by Brad.

The solution was to run a new #6 wire from the battery contactor at the rear battery to the buses up front so as to avoid the voltage drop developing on the #2 wire at the starter contactor. This seems to have solved the problem.

Furthermore, Brad advised on building in the ability to "boot strap" an independent electrical power capability to the PMAG(s) in the event of a weak main battery. If you you have a weak battery you may get the engine to turn over...but that weak battery almost assuredly will be at a voltage during start that will prevent the PMAG(s) from firing.

My solution was to buy a cheap 8 AA cell battery pack with plug from Amazon. I keep it in one of the seat backs. Should I have a weak main battery I simply plug my AA cell pack into a receptacle behind the instrument panel. This receptacle is wired directly to the PMAG power (bypassing the normal power switch). Works like a champ. Using this setup with a weak battery, if the starter can get one of the cylinders to TC, my PMAG will throw a spark.

David

Last edited by DCBrown198 : 06-14-2022 at 02:10 PM. Reason: grammar
Reply With Quote
  #45  
Old 06-14-2022, 02:34 PM
Carl Froehlich's Avatar
Carl Froehlich Carl Froehlich is online now
 
Join Date: Dec 2007
Location: Dogwood Airpark (VA42)
Posts: 3,741
Default

David,

A weak battery is a weak battery. This is the root problem. Your running additional wires may mitigate but does not address this problem.

I can report that my dual PC-625 battery install in my old RV-10 never had this problem. The new RV-10 will be done the same.

Carl
Reply With Quote
  #46  
Old 06-15-2022, 11:54 AM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 7,307
Default

Quote:
Originally Posted by Walt View Post
Don't get me wrong, I think Brad and the others at EMAG do a great job and provide excellent service, a model company in that regard.
I just think some of the touted advantages as compared to mags are somewhat exaggerated, lately I've sent back a number of units for bearing changes which ends up costing around a kilo buck (for 2 units) with service cost and labor for customers. I've also had to spend quite a bit of time correcting/repairing bad wiring/installations at the less-than-ideal connector they use.
Are the advantages worth it, for some folks perhaps it is, for me, not so much.
I am a believer in the fuel efficiency benefits of EI, with proper advance, in cruise. But just do not get the fascination with Pmags. 100 hour inspections, $500 bearing replacements, automatic timing changes, sub-par connectors, no warranty if over a certain unobtainable temperature, etc. My EI has magnets on the flywheel with 0 maintenance and electronics on the cold side of the firewall. A $200 inspection or a $500 bearing swap easily covers the cost of a $30 backup battery with biannual replacement, mitigating the benefits of the built in alternator. And the battery still works at 700 RPM.

Just one guy's opinion.

Larry
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019

Last edited by lr172 : 06-15-2022 at 12:02 PM.
Reply With Quote
  #47  
Old 06-15-2022, 12:06 PM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 7,307
Default

Quote:
Originally Posted by DCBrown198 View Post
Away from home I had one 6-cylinder PMAG internal alternator fail at 45 hours. Unit still provided excellent ignition for start, and flight. Had I developed a dead electrical system then that one PMAG would have died. I have two...so the redundancy was acceptable for the flight home. Emag promptly repaired the unit at no charge.

RV-10 builders take note. If you have your aircraft battery(s) in the rear as the plans call for, and you pull your bus power from the battery side of the starter contactor at the firewall, as the Van's generic electrical system describes, you may have starting problems with the PMAGs.

This is rooted in the voltage drop seem at the starter contactor as the starter is pushing the engine thru each compression stroke. Turns out that the voltage drop at the upper stage of each cylinder compression (right before the PMAG fires during start) is just enough to affect the PMAG and it may not send a spark at TC. After much frustration and trying to figure out why my engine would not start I was informed of this RV-10 issue by Brad.

The solution was to run a new #6 wire from the battery contactor at the rear battery to the buses up front so as to avoid the voltage drop developing on the #2 wire at the starter contactor. This seems to have solved the problem.

Furthermore, Brad advised on building in the ability to "boot strap" an independent electrical power capability to the PMAG(s) in the event of a weak main battery. If you you have a weak battery you may get the engine to turn over...but that weak battery almost assuredly will be at a voltage during start that will prevent the PMAG(s) from firing.

My solution was to buy a cheap 8 AA cell battery pack with plug from Amazon. I keep it in one of the seat backs. Should I have a weak main battery I simply plug my AA cell pack into a receptacle behind the instrument panel. This receptacle is wired directly to the PMAG power (bypassing the normal power switch). Works like a champ. Using this setup with a weak battery, if the starter can get one of the cylinders to TC, my PMAG will throw a spark.

David
Sorry, but that is just poor design engineering. In the auto world all engine electronics work down to 8.5-9 volts in order to deal with starter draw on a weak battery. I remember SDS posting that there units don't drop out until 9 volts as well.

Larry
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019

Last edited by lr172 : 06-15-2022 at 12:15 PM.
Reply With Quote
  #48  
Old 06-15-2022, 01:44 PM
Bavafa Bavafa is offline
 
Join Date: Oct 2007
Location: Sacramento, CA
Posts: 3,943
Default

Quote:
Originally Posted by lr172 View Post
Sorry, but that is just poor design engineering. In the auto world all engine electronics work down to 8.5-9 volts in order to deal with starter draw on a weak battery. I remember SDS posting that there units don't drop out until 9 volts as well.

Larry
With that in mind, one could say, in an aircraft any ignition that can not be self-sustaining for power is a poor design engineering.

Self sustaining and super easy of installation has been one of my primary attraction to PMAG. In three airplane that I have owned and installed PMAG, none failed or needed service by PMAG.
__________________
Mehrdad
N825SM RV7A - IO360M1B - SOLD
N825MS RV14A - IO390 - SOLD
N258SM RV14A - IO390EXP119 - Out of Paint shop & flying
Dues paid
Reply With Quote
  #49  
Old 06-15-2022, 03:38 PM
Ironflight's Avatar
Ironflight Ironflight is offline
VAF Moderator / Line Boy
 
Join Date: Jan 2005
Location: Dayton, NV
Posts: 13,091
Default

Quote:
Originally Posted by lr172 View Post
Sorry, but that is just poor design engineering. In the auto world all engine electronics work down to 8.5-9 volts in order to deal with starter draw on a weak battery. I remember SDS posting that there units don't drop out until 9 volts as well.

Larry
Just so the record is clear, you can power a P-Mag with a 9 volt battery and get a good startÖ.Iíve done it just to see if what Brad says works - and it does.
__________________
Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 03:49 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.