The Ford Barn

Chris Haynes · 04-23-2014, 01:00 PM

Does anybody know what the amount of auto advance is in a Wico JEM magneto?

Crazydaddyo · 04-23-2014, 02:09 PM

There is no auto advance in the Wico Magnetos.

.

Chris Haynes · 04-23-2014, 03:14 PM

There is in the JEM models. I just don't know how much.The Wico JEM 1509 models were made specifically for Fords.

Crazydaddyo · 04-23-2014, 09:45 PM

No advance. There is a retard feature called an impulse drive. It retards the timming for starting. Once the engine reaches idle speed,the timming is fixed.

Chris Haynes · 04-23-2014, 11:33 PM

Quote:

Originally Posted by Crazydaddyo

No advance. There is a retard feature called an impulse drive. It retards the timming for starting. Once the engine reaches idle speed,the timming is fixed.

If it retards to start then advances that is what I mean. I am just trying to find out how much the retard/advance is?

Crazydaddyo · 04-24-2014, 08:44 AM

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If you are asking how much advance to account for to set the initial timing, then the answer is I don't know. But you can't set the timing on a mag that way. I've had the best results by setting the timing while the engine is running @ 1200 rpm. Because the timing is fixed, you have to set the timing where you want to run it. I set it @ 25 - 28 deg. advance @ 1200 rpm. Drive the car around and see if there is any detonation (ping or knock) then adjust up or down accordingly. If it pings, back down the timing a little. If no ping, bump the timing up a little. Once you are happy, put your timing light on it to see where it is and write it down.

just plain bill · 04-24-2014, 11:55 AM

Specific for Ford industrial engines usually farm equipment.

If the mag has the impulse it will have what is called a lag angle instead of calling it an advance. usually 9 to 12 degrees. the impulse mechanism should kick out at from 150 rpm's to plus 200 rpm's. Initial timing is set at TDC turn mag shaft until impulse snaps at number 1 post on mag cap then install and align number 1 wire to number 1 cylinder. Then adjust as CDO said usually just so it doesn't kick back at cranking speed.

The magneto runs at what ever you set it at but the rotor lags behind at cranking speeds at what ever the lag angle built into the magneto so you could say it retards the spark that amount but again , it is called the "lag angle".

I remember when some engines had a manual impulse that was a small lever on the magneto that you set before cranking because they had no starter and had to be hand cranked. Been there, done that, but didn't get a T shirt

Chris Haynes · 04-24-2014, 12:40 PM

Thanks to you all for sharing.

johnneilson · 04-24-2014, 02:45 PM

Not hijack the thread, I have been told that Porsche distributors or mags can be adapted to Model A/B motors.
Has anyone here done this?
I have an old one, it indicates 0° 1750 - 12 1/2° 1900
This would be nice as long as the 1700-1900 is crank speed and not mag speed.

My side drive Bendix has lag, I can just imagine trying to hand prop an old airplane without it.

John

Crazydaddyo · 04-24-2014, 03:06 PM

John,
I have seen those Mags too. The ones I've seen are Vertex mags. I have talked to some one at Don Ziggs about centrifugal advance on vertex mags and they say yes, it is possible. I haven't done it yet, but I do have a 4 cyl. Vertex mag that I would like to send to them and have it set up for the street.

If I recall correctly, the VW / Porsche mag run the opposite way then a Model A / B..

04-23-2014, 01:00 PM	#1
Chris Haynes Senior Member Join Date: May 2010 Location: Camarillo, CA and Pine Grove, CA Posts: 2,832	Wico JEM Magneto questions Does anybody know what the amount of auto advance is in a Wico JEM magneto? __________________ 1921 Runabout 1930 Tudor Early 1930 AA Speed costs money. How fast do you want to go?

04-23-2014, 02:09 PM	#2
Crazydaddyo Senior Member Join Date: May 2010 Location: Orange, Ca. Posts: 197	Re: Wico JEM Magneto questions There is no auto advance in the Wico Magnetos. .

04-23-2014, 03:14 PM	#3
Chris Haynes Senior Member Join Date: May 2010 Location: Camarillo, CA and Pine Grove, CA Posts: 2,832	Re: Wico JEM Magneto questions There is in the JEM models. I just don't know how much.The Wico JEM 1509 models were made specifically for Fords. __________________ 1921 Runabout 1930 Tudor Early 1930 AA Speed costs money. How fast do you want to go?

04-23-2014, 09:45 PM	#4
Crazydaddyo Senior Member Join Date: May 2010 Location: Orange, Ca. Posts: 197	Re: Wico JEM Magneto questions No advance. There is a retard feature called an impulse drive. It retards the timming for starting. Once the engine reaches idle speed,the timming is fixed.

04-24-2014, 08:44 AM	#6
Crazydaddyo Senior Member Join Date: May 2010 Location: Orange, Ca. Posts: 197	Re: Wico JEM Magneto questions Sponsored Links (Register now to hide all advertisements) If you are asking how much advance to account for to set the initial timing, then the answer is I don't know. But you can't set the timing on a mag that way. I've had the best results by setting the timing while the engine is running @ 1200 rpm. Because the timing is fixed, you have to set the timing where you want to run it. I set it @ 25 - 28 deg. advance @ 1200 rpm. Drive the car around and see if there is any detonation (ping or knock) then adjust up or down accordingly. If it pings, back down the timing a little. If no ping, bump the timing up a little. Once you are happy, put your timing light on it to see where it is and write it down.

04-24-2014, 11:55 AM	#7
just plain bill Senior Member Join Date: May 2010 Posts: 397	Re: Wico JEM Magneto questions Specific for Ford industrial engines usually farm equipment. If the mag has the impulse it will have what is called a lag angle instead of calling it an advance. usually 9 to 12 degrees. the impulse mechanism should kick out at from 150 rpm's to plus 200 rpm's. Initial timing is set at TDC turn mag shaft until impulse snaps at number 1 post on mag cap then install and align number 1 wire to number 1 cylinder. Then adjust as CDO said usually just so it doesn't kick back at cranking speed. The magneto runs at what ever you set it at but the rotor lags behind at cranking speeds at what ever the lag angle built into the magneto so you could say it retards the spark that amount but again , it is called the "lag angle". I remember when some engines had a manual impulse that was a small lever on the magneto that you set before cranking because they had no starter and had to be hand cranked. Been there, done that, but didn't get a T shirt Last edited by just plain bill; 04-24-2014 at 12:13 PM.

04-24-2014, 12:40 PM	#8
Chris Haynes Senior Member Join Date: May 2010 Location: Camarillo, CA and Pine Grove, CA Posts: 2,832	Re: Wico JEM Magneto questions Thanks to you all for sharing. __________________ 1921 Runabout 1930 Tudor Early 1930 AA Speed costs money. How fast do you want to go?

04-24-2014, 02:45 PM	#9
johnneilson Senior Member Join Date: Jun 2010 Location: 34.22 N 118.36 W Posts: 1,056	Re: Wico JEM Magneto questions Not hijack the thread, I have been told that Porsche distributors or mags can be adapted to Model A/B motors. Has anyone here done this? I have an old one, it indicates 0° 1750 - 12 1/2° 1900 This would be nice as long as the 1700-1900 is crank speed and not mag speed. My side drive Bendix has lag, I can just imagine trying to hand prop an old airplane without it. John

04-24-2014, 03:06 PM	#10
Crazydaddyo Senior Member Join Date: May 2010 Location: Orange, Ca. Posts: 197	Re: Wico JEM Magneto questions John, I have seen those Mags too. The ones I've seen are Vertex mags. I have talked to some one at Don Ziggs about centrifugal advance on vertex mags and they say yes, it is possible. I haven't done it yet, but I do have a 4 cyl. Vertex mag that I would like to send to them and have it set up for the street. If I recall correctly, the VW / Porsche mag run the opposite way then a Model A / B.. Last edited by Crazydaddyo; 04-24-2014 at 03:29 PM.