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B21 ignition

Mr.Borrie

The Sneaky F*ing Ukrainian
Joined
Aug 1, 2006
Location
Netherlands
Its been so long since i had the b21 in my 242 i just forgot.
So who can tell me how the ignition on a B21 77 240 works?
Does it involve Some wiring and computers or can i compare it to a b20? (Just a coil and distributor)


My followup question is, can i put in that B21 distributor in any b230 block and run it?
 
The breakerless ignition system is the same for B20 and B21 although the distributor itself is different. It's a stand alone system so there is no computer, just an amplifier/transistor unit.

BreakerlessWiringDiagram.jpg


It will fit any redblock so long as you have an intermediate shaft with the drive gear.
 
My followup question is, can i put in that B21 distributor in any b230 block and run it?

Yes and no.

You can run it with LH 1.o, 2.o, 2.2 and marine/ non US carburetor setups but not LH 2.4, or 3.1, not sure about Regina.

The timing curve is controlled mechanically and not intended for the engine you’d be installing it on, also you’d lose the knock sensor function and could run into major trouble with predetonation especially with a turbo.

I have twice run breakerless on newer cars, one an 83 245 and briefly on a 90 740 turbo also converted to LH 2.2.

Before I forget I once ran breakerless (with the stock distributor) on a cushman mini truck to defeat the electronic speed governor.
 
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I am planning on running a carb on a b230 engine. Seems like thats Will fly by the looks of info above. Ill take IMS with drive gear
 
I have a few A”s around. Might even got a vx3 somewhere.
Good to know this option of the blockmounted and cab is possible.
I sold so much of the 242 turbo project but have a hard time selling the body

With a running engine in it on a budget i think that would be helpfull
 
The breakerless ignition system is the same for B20 and B21 although the distributor itself is different. It's a stand alone system so there is no computer, just an amplifier/transistor unit.

BreakerlessWiringDiagram.jpg


It will fit any redblock so long as you have an intermediate shaft with the drive gear.

What is "A control unit" in this picture though?
 
As I understand it the control unit amplifies the signal from the impulse sender so that it can be used to trigger a transistor that fires the coil.
 
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