Original Posted By: Ben Charvet
Listers,Here is a copy of an email I just sent to Larry Morlock detailing my 2nd mag drive troubles, after he inquired about it. Hi Larry,I had 13 hours on her (in flight). Maybe another 10 on the ground. During the flight the trouble occurred, I had checked the mags (in flight) individually before I left the proximity of the airport. All seemed well so I ventured out. The engine started running rough, and I checked the mags to discover that the cam gear-driven mag appeared to be completely dead. As of this date, I am still unsure why the engine continued running rough after I shut off that mag, and switched over to the crank mag. That is still a mystery to me. The only thing I can think of, is that in my panic, maybe I left the switch on "both" and the cam-driven mag was catching periodically (because of the partial tooth situation) and it was sending wild sparks in there.So I am not quite sure even now what happened, or exactly when. As you can see from the photos about 30% of the gear teeth are completely cracked off. The remaining teeth appear to be "worn" off. This is my speculation: There was insufficient clearance between the aluminum timing gear and the steel magneto gear. I had no trouble inserting and mounting that magneto at all, so no red flags were raised at that time. In my ignorance, I did not check the clearance between the gears. Over a period of hours, pressure was exerted onto the aluminum gear teeth and the metal failed on a number of the teeth, either from fatigue, or just the continued "mooshing" of the steel mag gear teeth against the aluminum teeth.When I contacted Ken Perkins, he speculated the same, and said the fix was adding shims (or extra gasket thickness) between the mag housing (casting that the mag is bolted to) and the engine block to achieve a clearance of four thousandths. This action would necessarily give more clearance between the two gears in question. But upon further examination, this action creates another problem. It is kind of hard to explain in an email, but there are three bolt holes that would have to be elongated, in the flat timing gear cover, in order to allow those three timing gear cover bolts to line up with the holes in the back of the engine block. I guess this would not be that big of a deal because only a few thousands of an inch would be needed. I myself have decided to go in another direction as far as the 2nd (redundant) ignition system goes (mostly to satisfy my wife). The Model A car suppliers sell an electronic ignition module that drops into a traditional distributor body. It will appear to be a stock Model A ignition system. Downside for me, is that I need a battery. I found a light weight battery at Wicks (4.4 lbs) that I will use. Another hang up is how is it recharged? I will maybe get a solar cell to put out when I am on the ground. Who knows, after you have proven the viability of the Perkins mag drive, I might go back to that! BTW Falluca told me that the aluminum gear should have had no problem with this set-up if clearances were correct.I think you would be wise to, during your on-ground break-in period, periodically remove that mag and peer in there to closely inspect that gear to see how it is doing. BTW, there was no apparent wear or damage that I can detect on the steel mag gear.I am willing to send you this aluminum gear for your close inspection. You may be able to glean some clues upon close examination. Let me know and I will UPS or mail it over to you.Please ask me more specific questions if you have them, and I will be more than glad to help however I can. Dan________________________________________________________________________________Date: Thu, 20 Jan 2011 08:26:35 -0500
Pietenpol-List: Model A Mag drive
Pietenpol-List: Re: Model A Mag drive
Original Posted By: "bender"
Subject: Pietenpol-List: Re: access panel for bellcrankJohn, I left the second bay behind the seat back on the bottom of the fuselage uncovered and made an cover out of aluminum sheet to cover it. I simply screwed it in with #6 x 1/2" stainless wood screws. It gives great accessto those four elevator turnbuckles that I have directly connecting the elevator cables to the bellcrank. Matt PaxtonOn Tue, Jan 18, 2011 at 10:26 AM, John Kuhfahl wrote:>>> I want to put the plate in because you just can not get to anything>> through the two side inspection plates already there. I saw Oscar's>> yesterday, but wanted to see where other's have located it, how big, and how>> you supported the plate, etc.>>>> -->> John Kuhfahl, Lt Col USAF (Ret),>> PresIident, KUHLCOUPER LLC________________________________________________________________________________Subject: Pietenpol-List: Re: Model A Mag drive
Subject: Pietenpol-List: Re: access panel for bellcrankJohn, I left the second bay behind the seat back on the bottom of the fuselage uncovered and made an cover out of aluminum sheet to cover it. I simply screwed it in with #6 x 1/2" stainless wood screws. It gives great accessto those four elevator turnbuckles that I have directly connecting the elevator cables to the bellcrank. Matt PaxtonOn Tue, Jan 18, 2011 at 10:26 AM, John Kuhfahl wrote:>>> I want to put the plate in because you just can not get to anything>> through the two side inspection plates already there. I saw Oscar's>> yesterday, but wanted to see where other's have located it, how big, and how>> you supported the plate, etc.>>>> -->> John Kuhfahl, Lt Col USAF (Ret),>> PresIident, KUHLCOUPER LLC________________________________________________________________________________Subject: Pietenpol-List: Re: Model A Mag drive
Re: Pietenpol-List: Re: Model A Mag drive
Original Posted By: Rick Holland
Hey Dan ... i was thinking the same thing... but with the FSI distributor... ithas centrifugal advance that is a full 28 deg at 1750 rpm there is another distributor drive coming out from the secrets of speed guys...uses a VW distributor on the timing cover with a separate gear .. http://www.secretsofspeed.com/IGNITIONS.htmlooks pretty cool..i gave my engine to Rich from antique engine rebuilders at the local model a swapmeet last weekend... we talked about your troubles a bit..looking forward to hanging it on the nosejeffRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 20 Jan 2011 11:54:53 -0700Subject: Re: Pietenpol-List: Re: Model A Mag drive
Hey Dan ... i was thinking the same thing... but with the FSI distributor... ithas centrifugal advance that is a full 28 deg at 1750 rpm there is another distributor drive coming out from the secrets of speed guys...uses a VW distributor on the timing cover with a separate gear .. http://www.secretsofspeed.com/IGNITIONS.htmlooks pretty cool..i gave my engine to Rich from antique engine rebuilders at the local model a swapmeet last weekend... we talked about your troubles a bit..looking forward to hanging it on the nosejeffRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 20 Jan 2011 11:54:53 -0700Subject: Re: Pietenpol-List: Re: Model A Mag drive
> Pietenpol-List: Re: Model A Mag drive
Original Posted By:> jfaith(at)solairusaviation.com
Here's another thought. The Aerovee guys run a very simple fixed advance secondary. Don't know much about it except it's very simple. I believe they only run one set of plugs too.Doug DeverIn beautiful Stow Ohio> Subject: Pietenpol-List: Re: Model A Mag drive
Here's another thought. The Aerovee guys run a very simple fixed advance secondary. Don't know much about it except it's very simple. I believe they only run one set of plugs too.Doug DeverIn beautiful Stow Ohio> Subject: Pietenpol-List: Re: Model A Mag drive
Re: Pietenpol-List: Re: Model A Mag drive
Original Posted By: at7000ft(at)gmail.com
You are correct The Aerovee actually uses 4 modules and yes it uses dual plugs. I was thinking of the Great Plains VW.They have a fixed secondary.Doug DeverIn beautiful Stow OhioDate: Thu=2C 20 Jan 2011 14:07:43 -0700Subject: Re: Pietenpol-List: Re: Model A Mag drive
You are correct The Aerovee actually uses 4 modules and yes it uses dual plugs. I was thinking of the Great Plains VW.They have a fixed secondary.Doug DeverIn beautiful Stow OhioDate: Thu=2C 20 Jan 2011 14:07:43 -0700Subject: Re: Pietenpol-List: Re: Model A Mag drive
Pietenpol-List: Model A Mag drive
Original Posted By: helspersew(at)aol.com
>> Subject: Re: Pietenpol-List: FW: Hand propping an airplane>> To: pietenpol-list(at)matronics.com>>>>>>> On 1/18/2011 7:59 AM, Jack Phillips wrote:>>>> Y'all be careful out there, unless you want to become ventilated>>> like>>>> this fellow:>>>>>>>> Jack Phillips>>>>>>>> NX899JP "Icarus Plummet">>>>>>>> Raleigh, NC>>>>>>>> ----------------------------------------------------------------->>> ------->>> We've got a one-armed pilot whose Champ got him after about 3,000>>> hours>>> of experience. It only takes once. Tie the tail EVERY TIME, chock>>> the>>> wheels EVERY TIME, then get ready to run like crazy if you put the>>> throttle in the wrong position JUST THIS ONCE. That's what got our>>> guy,>>> who is lucky to still be alive.>>>>>> Darrel Jones>>> Pfeifer Sport>>> Sonoma, CA>>>>>>>>>>>>>>________________________________________________________________________________Subject: Pietenpol-List: Model A Mag drive
>> Subject: Re: Pietenpol-List: FW: Hand propping an airplane>> To: pietenpol-list(at)matronics.com>>>>>>> On 1/18/2011 7:59 AM, Jack Phillips wrote:>>>> Y'all be careful out there, unless you want to become ventilated>>> like>>>> this fellow:>>>>>>>> Jack Phillips>>>>>>>> NX899JP "Icarus Plummet">>>>>>>> Raleigh, NC>>>>>>>> ----------------------------------------------------------------->>> ------->>> We've got a one-armed pilot whose Champ got him after about 3,000>>> hours>>> of experience. It only takes once. Tie the tail EVERY TIME, chock>>> the>>> wheels EVERY TIME, then get ready to run like crazy if you put the>>> throttle in the wrong position JUST THIS ONCE. That's what got our>>> guy,>>> who is lucky to still be alive.>>>>>> Darrel Jones>>> Pfeifer Sport>>> Sonoma, CA>>>>>>>>>>>>>>________________________________________________________________________________Subject: Pietenpol-List: Model A Mag drive
Re: Pietenpol-List: Re: Model A Mag drive
Original Posted By: Rick Holland
> To: pietenpol-list(at)matronics.com> om>> > Hey Dan ... i was thinking the same thing... but with the FSI distributor... it has centrifugal advance that is a full 28 deg at 1750 rpm > there is another distributor drive coming out from the secrets of speed guys... uses a VW distributor on the timing cover with a separate gear .. > http://www.secretsofspeed.com/IGNITIONS.htm> looks pretty cool..> i gave my engine to Rich from antique engine rebuilders at the local model a swap meet last weekend... we talked about your troubles a bit..> looking forward to hanging it on the nose> > jeff> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 685#327685> > > > > > > ============================================> > > ________________________________________________________________________________Date: Thu, 20 Jan 2011 14:07:43 -0700Subject: Re: Pietenpol-List: Re: Model A Mag drive
> To: pietenpol-list(at)matronics.com> om>> > Hey Dan ... i was thinking the same thing... but with the FSI distributor... it has centrifugal advance that is a full 28 deg at 1750 rpm > there is another distributor drive coming out from the secrets of speed guys... uses a VW distributor on the timing cover with a separate gear .. > http://www.secretsofspeed.com/IGNITIONS.htm> looks pretty cool..> i gave my engine to Rich from antique engine rebuilders at the local model a swap meet last weekend... we talked about your troubles a bit..> looking forward to hanging it on the nose> > jeff> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 685#327685> > > > > > > ============================================> > > ________________________________________________________________________________Date: Thu, 20 Jan 2011 14:07:43 -0700Subject: Re: Pietenpol-List: Re: Model A Mag drive
> > Pietenpol-List: Re: Model A Mag drive
Original Posted By: Doug Dever
> > To: pietenpol-list(at)matronics.com>> >> jfaith(at)solairusaviation.com>> >> > Hey Dan ... i was thinking the same thing... but with the FSI> distributor... it has centrifugal advance that is a full 28 deg at 1750 rpm> > there is another distributor drive coming out from the secrets of speed> guys... uses a VW distributor on the timing cover with a separate gear ..> > http://www.secretsofspeed.com/IGNITIONS.htm> > looks pretty cool..> > i gave my engine to Rich from antique engine rebuilders at the local> model a swap meet last weekend... we talked about your troubles a bit..> > looking forward to hanging it on the nose> >> > jeff> >> >> >> >> > Read this topic online here:> >> > http://forums.matronics.com/viewtopic.p ... 685#327685> >> >> = Archive Search & Download, 7-Day Browse, Chat, FAQ,> &g====================> > _====>> >> >> >>> *>> *>>-- Rick HollandCastle Rock, Colorado"Logic is a wreath of pretty flowers, that smell bad"________________________________________________________________________________
> > To: pietenpol-list(at)matronics.com>> >> jfaith(at)solairusaviation.com>> >> > Hey Dan ... i was thinking the same thing... but with the FSI> distributor... it has centrifugal advance that is a full 28 deg at 1750 rpm> > there is another distributor drive coming out from the secrets of speed> guys... uses a VW distributor on the timing cover with a separate gear ..> > http://www.secretsofspeed.com/IGNITIONS.htm> > looks pretty cool..> > i gave my engine to Rich from antique engine rebuilders at the local> model a swap meet last weekend... we talked about your troubles a bit..> > looking forward to hanging it on the nose> >> > jeff> >> >> >> >> > Read this topic online here:> >> > http://forums.matronics.com/viewtopic.p ... 685#327685> >> >> = Archive Search & Download, 7-Day Browse, Chat, FAQ,> &g====================> > _====>> >> >> >>> *>> *>>-- Rick HollandCastle Rock, Colorado"Logic is a wreath of pretty flowers, that smell bad"________________________________________________________________________________