Converting from mag to electronic

[wolram]

Ok magnetoes are fine buit expensive to keep in A1 condition, so i want to convert to electronic, i have the means to manufacture the body to hold the new mechanism, and guess i can tailor it to fit some prop trigger mechanism
for the LT, the problem is a control for maping the required advance/retard,
i am quite niffty with a soldering iron, so i think i could build the electronics,
but how do i go about maping it to the engine?

 

[wolram]

This is for a single cylinder engine

 

[Intuitive]

This is for a single cylinder engine

Any expanded Blue Prints of the Engine?

Model:
Type:
Year:
Spects:

 

[FredGarvin]

So you're first hurdle would be to get some kind of cam sensor to dictate the firing...right? It's been a while since I have dealt with this stuff. For a single cylinder, is it really that beneficial to give yourself a lead/retard on the firing?

 

[wolram]

So you're first hurdle would be to get some kind of cam sensor to dictate the firing...right? It's been a while since I have dealt with this stuff. For a single cylinder, is it really that beneficial to give yourself a lead/retard on the firing?

It sure is for cold starting Fred, and performance of course, i have several ways i could go,manual advance /retard mag, Points/coil, electronic.
If i can find an electronic pick up i can make an adapter housing drive shaft ect, the electronics seem simple, apart from the advance/retard, i think i need some sort of feed back to the circuit ie engine rpm but that could come from the pick up i think, or maybe i could buy a (black box) off the shelf,
all very much up in the air at the minute, i could buy a ready made convertion but that comes to 500 UK+.

 

[FredGarvin]

You would have to vary the advance/retard based on throttle position as well as engine RPM I would think. Back when I worked in automotive powertrain, I remember quite a few parameters were involved in the calculations the engine PCM would do to adjust it. I think that RPM would be the bare minimum if your load increases steadily with RPM. If not, I think you'd have to work in throttle position as well.

 

[wolram]

http://www.electronics-lab.com/projects/automotive/008/index.html

Fred this is a basic circuit that looks like it uses the mechanical advance
retard, and no other inputs AFAIK.

 

[wolram]

This site is akin to what i will
try to make, it seems all i need for the trigger is an hall effect sensor, this could be possitioned to pick up on some rotating
engine part, i think i will need an rpm sensor (trigger) and a electronic vacuum sensor for best results.

http://www.realclassic.co.uk/techfiles/tech03061700.html

Mapping the curve is still the headache, this site says 1 degree per 100 rpm
for this bike.

The multi spark option ie the plug fires several times sounds good .

 

[FredGarvin]

I know cam sensors are indeed hall effect sensors on larger engines.

I'm going to have to do some reading here.

 

[wolram]

Any expanded Blue Prints of the Engine?

Model:
Type:
Year:
Spects:

Sorry Intuitive i missed this post.

Model: velocette
Type: MAC
Year: 1960
cc: 349
Compression ratio: 6.75 to one
Carburetter: 15/16 Amal
Electrics: 6v

 

[RG500]

Ah yes, a Velocette, have your tried posting this on the "Brit Bike Forum"?
Cheers,
RG500

 

[Intuitive]

Sorry Intuitive i missed this post.

Model: velocette
Type: MAC
Year: 1960
cc: 349
Compression ratio: 6.75 to one
Carburetter: 15/16 Amal
Electrics: 6v

Hi Wolram.

What's the Stator count on your Magneto?

I have seen ones with 4 Stators and some up to 10 Stators on the Stator Ring.

Are you using a rebuilt original Magneto or are you using a Modern cross referenced Magneto?

 

[wolram]

Hi Wolram.

What's the Stator count on your Magneto?

I have seen ones with 4 Stators and some up to 10 Stators on the Stator Ring.

Are you using a rebuilt original Magneto or are you using a Modern cross referenced Magneto?

It looks like the original mag, i have asked around, and it seems the auto
advance on these lucas type kif mags have always had problems, the auto advance is type jy16a, and most tend to fit a mag with manual advance.

I have not taken the mag apart, as after reading 10s of peoples problems
with this mag, i decided it would be best to go electronic.

 

[wolram]

Ah yes, a Velocette, have your tried posting this on the "Brit Bike Forum"?
Cheers,
RG500

I just spent an enjoyable hour on that forum, great place RG500