Need an electrical genius, don't know where to turn.
 

This is in no way Flathead related but I know there are some very smart people on here. I am trying to get a B-24 Auxiliary power unit running and I'm not getting a spark. It has a magneto with 2 condensers. I believe they are bad. They are labeled Wico x4215. I can not find a cross reference anywhere. Can I just guess on the replacements or will that cause problems? Help.

Re: Need an electrical genius, don't know where to turn.
 

X4215

Capacitors

CAPACITOR,FIXED,PAPER DIELECTRIC
MFG P/N: X4215
NSN: 5910-00-364-6995
FSC: 5910 - Capacitors
MFG: Wico-Prestolite Co The Div Of Eltra
Description: CAPACITOR,FIXED,PAPER DIELECTRIC
ACT NOW! SUBMIT A QUICK QUOTE.

Technical Characteristics

• Case Material
  
  metal
• Body Style
  
  w/mtg bracket, terminal(s) on one end
• Capacitance Value Per Section
  
  0.150 microfarads single section
• Terminal Type And Quantity
  
  1 standard tube base
• Schematic Diagram Designator
  
  electrode(s) grounded to case
• Body Diameter
  
  0.594 inches nominal
• Tolerance Range Per Section
  
  -10.00/+10.00 percent single section
• Features Provided
  
  mounting hardware
• Nonderated Continuous Voltage Rating And Type Per Section
  
  200.0 dc single section
• Body Length
  
  1.781 inches nominal

Re: Need an electrical genius, don't know where to turn.
 

Ask a question on an antique car site about a B-24 power unit and get an answer. The amount of knowledge on this site is absolutely amazing!!!

Re: Need an electrical genius, don't know where to turn.
 

Maybe if I can get a .150 mfd condenser I can substitute it for the original?

Re: Need an electrical genius, don't know where to turn.
 

Wico mag sounds like a tractor. possibly...


Maybe if I can get a .150 mfd condenser I can substitute it for the original?

I would think so if you can mount it to ground. Not to worry as much about voltage.


added from a tractor forum... 6v,12v,24v... Smokstak is a good site too, but for me early tractors, hit/miss, and implement (most being 6v). The Bob referral is just circumstance.

""""McCoy, I agree with Bob. The condensors Voltage Withstand rating is farrrrrrrrrrrrrr higher then 6 or 12 volts anyway, soooooooooooo an off the shelf condensor wouldnt likely be any different if for a 6 or 12 or heck even a 24 volt system etc., CUZ THEY ARE RATED WAYYYYYYYYYY HIGHER THEN ANY OF THOSE VOLTAGES ANYWAY. The condensor is more of a current and energy absorbing passive device then anything thats voltage related or voltage sensitive or voltage dependant. Its job is to prevent premature burning up of the points and it does that by serving an as empty well/bank just sitting there waiting to accept the inrush of electrons that occurs when the points break open and the coils current reallyyyyyyyy wants to keep flowing somewhere, and its absorbing of them prevents as much arcing n sparking across the points which would quickly burn them up.

Its possible that condensors can break down and especially when they warm up, so since they are much cheaper then a coil anyway, Id try a new one if in doubt. If she still has problems after warm up then Id suspect the coil or the points among other things.
Hope this helps understanding of the condensor and why one used on a 6 or 12 volts system is most likely the exact same thing. Its NOT true that all condensors are 6 volts, they have a voltage withstand rating muchhhhhhhhh higher then 6 or 12 anyway as the voltage spike across them when the points break open is also muchhhhhhh higher then that as Bob explained.

Take care yall n God Bless
John T Retired Electrical Engineer """"


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Re: Need an electrical genius, don't know where to turn.
 

This is the only forum I'd ask a question like that , I know what kind of brilliant people are on here.

Re: Need an electrical genius, don't know where to turn.
 

I would think Rotorwrench would know where to get the right part. There must also be some antique airplane guys here with old radial engines that deal with hard to find parts or replacements. If I had more $ that would include me but I can only afford 1 expensive hobby!

Re: Need an electrical genius, don't know where to turn.
 

Does the putt-putt look like this?


Bob

Re: Need an electrical genius, don't know where to turn.
 

Hi there, some questions, Are the insulated connections or wires of both condensers joined together. Is there one magneto or two or is it a coil ignition with timing points and a battery required. Some detail photos would help. Automotive condensers are rated at approx. 600 volts so voltage is not an issue. You should have those condensers tested at and auto electrical shop or radio repair shop because they may not be the problem. Fit a couple of normal automotive condensers just for a test because it wont hurt anything. The magneto coil or coils may be open circuit. If you cant nut it out then have an auto electrical shop look at it for you. Regards, Kevin.

Re: Need an electrical genius, don't know where to turn.
 

Inspiration for the subject matter experts.

I made it a point to stop by Willow Grove when I was in Michigan last summer!

Edit: I am stupid and said Willow Grove. Bruce has it correct! Thanks to my online and "road family" for keeping me semi-straight.

Re: Need an electrical genius, don't know where to turn.
 

Run.............Willow Run.

Re: Need an electrical genius, don't know where to turn.
 

How epic is it that the B-24 was known within the company as the Model 32?

Re: Need an electrical genius, don't know where to turn.
 

Happy to have the backup Bruce! Thanks for making my lies more correct.

Re: Need an electrical genius, don't know where to turn.
 

The capacitors for Lucas rotating field motorcycle magnetos have to have a very high voltage rating, but for the rotating magnet type, the conventional type will do. Can you post a pic of your mag?

Re: Need an electrical genius, don't know where to turn.
 

I have an old Wisconson two cyl. engine that has a Wico mag. and got points and condenser for it from Brian's Mags 517-223-0929. Mark

Re: Need an electrical genius, don't know where to turn.
 

Look like you got your electrical genius.

Re: Need an electrical genius, don't know where to turn.
 

Great answers and no one said it should be posted somewhere else.

Re: Need an electrical genius, don't know where to turn.
 

Wico made a lot of mags. A person really needs to know the model number. They did make them for Wisconsin engines but a lot of others as well. Here is a link to some tractor stuff. https://antique-tractor-parts.steine...r/Wico-Magneto

Most mags use a capacitor that matches to the type of coil that is used internally. Every different type can be matched up to a different capacitive reactance. I would avoid using any old stock on a capacitor unless it is late enough to have mylar film or at least mica as an insulator. Wax paper deteriorates too much to sit around for too long. A lot of old mags can have substitutes depending on the shape of the original condenser. Lucas had some weird ones but Eisemann & Scintilla did too.

If it's a Homelite HRU-28 then it is likely a lot like a Briggs & Stratton except I think its a 2-stroker. I think these were used to charge the battery on B-24 and possibly other large aircraft. They may have also had applications for some tanks.

Here is another link with photos. https://www.smokstak.com/forum/showthread.php?t=108002

The HRU-28 used a FW or "fly wheel" mag. Parts are scarce for these but there are substitutes. Here is another link. http://www.magnetoparts.com/wico_fw.htm

Here's another one. Check the FW-1704 entry for OEM part numbers. https://oldcroak.com/wico-fw-series-mags-circa-1955-1/

Re: Need an electrical genius, don't know where to turn.
 

Thank you for all the advice. I've been busy the last few days but got around to it today. I replaced the 2 condensers with one later model automotive condenser and it now runs great. This place really does have a wealth of knowledge. Now I just need something 24 volts I can run with it or maybe a B-24?

Re: Need an electrical genius, don't know where to turn.
 

Here is my old Witte 3.5/4hp open crank throttler running on a Wico EK box mag. Run for hrs on a soup can of fuel. Batteries? we don't need no stinkin' batteries. Or intake push rods.
https://www.youtube.com/watch?v=YsVnPdRjCU4


Cool project Fibber, Looks real clean!!! Best of luck with it!




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Re: Need an electrical genius, don't know where to turn.
 

And there may be some new guys out there that are smart like the guys on here but I don't ever run across any fellows that are interested. When I worked at the TWA overhaul base in Kansas City, I was so impressed with guys who not only knew theory but could apply that theory in practice.

Re: Need an electrical genius, don't know where to turn.
 

Aircraft and some heavy equipment use 24-volt power. Those things were kind of a back up battery charger. I don't know what would happen if a pilot tried to start an 1830 engine on one of those. It might do OK with an inertial starter but it might kill the thing too. I just don't know.