B21F(&FT), anyone using stock dist. w/megasquirt

Seems the popular thing to do is swap to a LH2.2 hall sensor equipped distributor, not wanting to shell out the money for one, I'd like to use my stock dizzy that appears to be a VR type signal.


I've got the MS v3 board w/MSII which will take a VR signal if I read it correctly....using a MSD 6A to fire to plugs

I'd like to do crankfire in the furture, but for now, just want to get the silly think going...

Thanks

B21FT dizzy signal

I've always known this type of signal to be called a magnetic trigger. Similar but not the same to my understanding. I also was considering using this setup. I would look for magnetic trigger options instead of VR.

I just did a quick test on my workbench...hooked the 2 dizzy outputs directly to the VR inputs of the MSD box, got spark from the coil....time to continue wiring it up...

if you hook the distro into the msd it works, but then you get the whole curve the stock distro has. the 2.2 ones have no curve, so ms tells the coil when to fire.

I have a question. If MS tells the coil when to fire but that time is either ahead or behind where the dizzy is won't there be arcing from the rotor to the cap? Am I missing something here?

hormone83 said:

I have a question. If MS tells the coil when to fire but that time is either ahead or behind where the dizzy is won't there be arcing from the rotor to the cap? Am I missing something here?

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MS can be run a few different ways using the dizzy....

The most basic would be when the coil field collapses, MS gets the signal to fire the injectors, yet has no control of spark, dizzy operates normally with mechanical advance/vac retard

the other method, you modify the dizzy (or use an LH2.2(?) dizzy) that is mechaniclly "locked" so there is no advance/retard. The dizzy sends a signal to MS to provide orientation, the MS does the math and sends a signal to an MSD box, which fires the coil.

Yes, you do have to worry about arching if the rotor tip is too far away...to ensure you have a nice strong arc, you can cut open a "window" in a cap to view the arc. If "iffy", you change the position of the signal orientation or change the postion of the rotor, you could go so far as changing the shape of the tip that arcs with the cap, either make is smaller, or biasing it towards one direction.

spark check

Instead of cutting open a distributor cap. Just buy one of the clear ones for VW Beetles. They use the same distributor cap as the 240 kjet, the hall sensor, and the LH2.4 distributors. They come in clear, blue, red, and probably other colors like pink nowadays.

Hello. So I have a 79 242 and wanted to get some clarification on distributors. I believe my dizzy is a magnetic pick up, vacuum and mechanical advance, and fixed. Is this correct? Looking to control spark curve with stand alone. Is the 2.2 lh dizzy a block mounted and a direct replacement for my current one( physically) and has no mechanical or vacuum advance? Anyone have any advice on how to lock out my current dizzy?

AkPirate said:

I believe my dizzy is a magnetic pick up, vacuum and mechanical advance, and fixed [curve]. Is this correct?

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Yes

AkPirate said:

Is the 2.2 lh dizzy a block mounted and a direct replacement for my current one( physically) and has no mechanical or vacuum advance?

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Yes, but LH2.2 use a hall sensor (3-wire plug with: +12v, gnd, and signal).

AkPirate said:

Anyone have any advice on how to lock out my current dizzy?

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Find a LH2.2, unless they've become very $$$ or you're good at taking apart 50 year old possibly corroded assemblies, and can do some small welding.

Thank you!!! Anyone out there got a good LH 2.2 dizzy they want to sell?