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#1
Hi Gurus,
The v8 I'm using for my Cortina project had the old flapper EFI, which has been discarded. Is there a separate aftermarket module I can use to run the electronic dizzy from the original system, as I don't have the CPU (which I assume the dizzy connected to). Cheers, Rob.
 

Gargo

Active Member
#2
Yes.
I've used an Aldon amethyst connected to a Vitesse dizzy. www.aldonamethyst.co.uk
The dizzy was locked I.e. wire up the advance weights and dissconnect the vacuum, so the dizzy is now a 'static' crank sensor, the Amethyst controls the advance due to engine speed and vacuum.
The Amethyst was not able to sense the dizzy inductor alone, however together with a standard Vitesse Ignition Module it works. It is the box under the coil. It simply conditions and amplifies the dizzy signal into a stronger pulse.

In my research I believe that Vitesse Ignition Module can be replaced with an Intermotor 15210 Ignition Module, wired:
  • Coil positive to the terminal marked ‘B’ - Which will now be your Mappable Ignition, which in turn is wired to the coil
  • Coil negative to the terminal marked ‘C’ - Earth
  • Purple wire from the dizzy to terminal ‘W’
  • Orange wire to the terminal marked ‘G’

The dizzy wires are the black connector bottom right, into the Vitesse Ignition Module the box under the coil. The off white connector to the right is not connect. I should tidy this up, but once I got something working I usually move on to another project.

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#4
So there should be a separate module for the dizzy available from Landrover perhaps? When I say EFI was discarded, I mean I'm now using a downdraft carb.

I have a couple of nice rebuilt early dizzys with lumention upgrade that I got for my P6B - is it possible to just swap over the oil pump drive from later to early and use one of those?

Cheers.
 
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harveyp6

Well-Known Member
#5
I have a couple of nice rebuilt early dizzys with lumention upgrade that I got for my P6B - is it possible to just swap over the oil pump drive from later to early and use one of those?
You can fit the later SD1-on drive gear to the early dizzy, you just need to cut about 1/8" off the P6B dizzy oil pump drive tang to get it to fit
 

jp928

Well-Known Member
#8
Its not the type of fuelling thats the issue, its usually the CR that dictates the advance curve. Eg an 8.13:1 CR engine will have a much softer advance than a 9.25 or a 10.5 engine . If you look up the advance data in the manuals its obvious. You could use a 9.25 dizzy from a carb car in a 9.35 injected engine without any significant power loss. I have plotted the curves for 9.25 and 10.5 (best way, as the books dont give advance degrees for the two dizzies at the same rpm points), and the 10.5 dizzy has ~ 2deg more advance over most of the range than the 9.25 unit.
 

Gargo

Active Member
#9
you shouldn't use an 'EFI' dizzy on a carburetted car the advance curves are wrong
It's not so much that a particular curve is wrong, just that they are closer or further from the ideal.
No, mechanical advance dizzy will provide the ideal curve they are all compromises. Each engine is different, fuels have changed over time, temperatures are not static, etc, etc.
For these reasons I wanted to have a bespoke advance curve, I used an EFI dizzy because I had one.
The article you reference says "Avoid those models calibrated for injected engines. They have a very large curve". It is the curve that is the problem not the dizzy. I have overcome this by making my own advance curve, just using the dizzy as a crank sensor and of course a spark distributor. The spark timing is controled in the Aldon Amethyst. This is the same as changing the weights, springs and vacuum device, but quicker, cheaper and less compromise as you can program in the outliers.

Back to you question:
Is there a separate aftermarket module I can use to run the electronic dizzy from the original system
Yes, you can use it as it is but the the curve will not be ideal for your engine. However this can be overcome by using the dizzy together with a programmable ignition system.

G.
 
#10
Its not the type of fuelling thats the issue, its usually the CR that dictates the advance curve. Eg an 8.13:1 CR engine will have a much softer advance than a 9.25 or a 10.5 engine . If you look up the advance data in the manuals its obvious. You could use a 9.25 dizzy from a carb car in a 9.35 injected engine without any significant power loss. I have plotted the curves for 9.25 and 10.5 (best way, as the books dont give advance degrees for the two dizzies at the same rpm points), and the 10.5 dizzy has ~ 2deg more advance over most of the range than the 9.25 unit.
From a random pile of dizzys I guess there's no way to know what CR engine it originally came from then...?
 

Quagmire

Active Member
#11
The body of the dizzy will have a number stanped on the side, the workshop manual lists the different specs for each one and which engines they were for. I think I may have posted then previously, will see if I can find it for you...
 
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