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richarddurgee
Senior Member
Username: richarddurgee
Post Number: 3493
Registered: 11-2001
| | Posted on Sunday, February 08, 2015 - 12:44 pm: | 
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Palmer ZR2 Magneto
This photo is from a Palmer Catalog about 1930
does anyone recognize the magneto ?
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bruce_g
Member
Username: bruce_g
Post Number: 11
Registered: 12-2009
| | Posted on Sunday, February 08, 2015 - 04:44 pm: |
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Looks like a Bosch DU 2 |
richarddurgee
Senior Member
Username: richarddurgee
Post Number: 3494
Registered: 11-2001
| | Posted on Monday, February 09, 2015 - 09:40 am: |
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It appears that Palmer used the Du2 mag on the Twin ZR engines throughout its production ?
Trying to figure out Marine engine magnetos and the myriad different models as to actual application is a study within itself ! Manufacturers catalogs don't say who makes their mags or the models used and almost non existent information and articles written in boating publications over the years ??
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ernie
Senior Member
Username: ernie
Post Number: 1990
Registered: 01-2002
| | Posted on Monday, February 09, 2015 - 10:32 am: |
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From looking at the pic I think the mag was used just for looks. Zr2 engines did have a magneto option but not this particular magneto.
The ZR2 is not a 180 deg firing engine.
Note the Atwater Kent Distributor has the plug wires next to each other with 2 more places for wires that are not used which is correct.
This provides spark rotate 90 deg spark rotate 270 deg spark rotate 90 deg and so on
The mag in the pic can't do that as it doesn't have a distributor portion so it is a 180 degree firing sequence.
So now I am wondering...
Is it possible to get a mag like the one in the pic to fire in the right sequence?
Dick Day's NR2 is basically the same as a ZR2 with different cylinders. It has a Bosch DU4 Mag with 2 cylinders eliminated.
Palmer stated at various times over the years that pics in ads were not necessarily correct. Having parts made out of wood for ad pics was one comment that I remember well. |
richarddurgee
Senior Member
Username: richarddurgee
Post Number: 3496
Registered: 11-2001
| | Posted on Monday, February 09, 2015 - 11:34 am: |
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Ernie Thanks for the reply, I have been going round and round with the same questions you bring up ? One more step that is confusing is this 1943
ZR2 is all original, the top part of the timer and the magneto is missing--
It sure looks to me that the timer is a cuno, and I have photos of other ZR2's with the cuno also,on two cyl ones they fire 180 degrees ???
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This Confusion gives me good experience to apply for a job in Washington !
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ernie
Senior Member
Username: ernie
Post Number: 1991
Registered: 01-2002
| | Posted on Monday, February 09, 2015 - 03:20 pm: |
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Timer is easy and Bosch DU 4 mags are common.
Just short out the 2 plug wire terminals you don't use. I am pretty sure they are even reversible. The Cuno timer will have 2 terminals 90 deg apart. Of course you can use a 4 cylinder one and just ignore the 2 terminals you don't use. You can't use a 3 cylinder Cuno or a 180 deg/opposite terminal 2 cylinder one. |
ernie
Senior Member
Username: ernie
Post Number: 1992
Registered: 01-2002
| | Posted on Monday, February 09, 2015 - 03:27 pm: |
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These sound like John Deere 2 cylinder tractors AKA model A or a B
DA Dunk space space DA Dunk space space DA Dunk space space and so on... |
richarddurgee
Senior Member
Username: richarddurgee
Post Number: 3498
Registered: 11-2001
| | Posted on Monday, February 09, 2015 - 08:22 pm: |
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Searched photos, found this Palmer NR2.
Has 4 contact Cuno using two together
Looks like a Bosch DU2 ???
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ernie
Senior Member
Username: ernie
Post Number: 1994
Registered: 01-2002
| | Posted on Tuesday, February 10, 2015 - 07:13 am: |
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I found some similar pics.
So if the cam for the points in the mag has 2 lobes 90 deg apart and the contacts for the secondary output are at 90 deg instead of 180 it should work. If this is the case when looking for a DU 2 you would need to take the cover off the points and make sure it is a 90 deg spacing and not 180 deg spacing. |
rogerd
Advanced Member
Username: rogerd
Post Number: 31
Registered: 01-2010
| | Posted on Tuesday, February 10, 2015 - 04:23 pm: |
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Could Ernie or others explain the rational for the 90 deg.timer producing the DA dunk space space DA dunk space space sequence. As opposed to the more common more even 180deg timer. I have the 90deg timer on my 3hp. Buffalo. Thanks Roger. |
ernie
Senior Member
Username: ernie
Post Number: 1996
Registered: 01-2002
| | Posted on Tuesday, February 10, 2015 - 07:32 pm: |
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It is to go with the style of the crankshaft.
Do both pistons go up and down together or is one up and one down.
Both together is 180 deg firing every time.
One up and one down is 90 deg firing with 270 deg of nothing.
Both together are statically out of balance but balanced power stroke wise.
One up and one down are statically balanced but out of balance power stroke wise.
One up and one down are basically half of a 4 cylinder.
Hope this helps
Ernie |
richarddurgee
Senior Member
Username: richarddurgee
Post Number: 3504
Registered: 11-2001
| | Posted on Wednesday, February 11, 2015 - 10:16 pm: |
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Found a Bosch DU1 and DU2 catalog.
The cams that operate the points and determine timing are the # 16 Steel Segments and are made into # 80 Timing control arm.
What's interesting is that this shows a single steel segment for the single cyl and the 180 degree steel segments for the two cyl, but no mention of a 90 degree Option ??
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