twin pnt dizzy

[robbzfc58]

ive been having some discussion lately about twin point dizzys compared to electronic on a red motor
   which is best
   is there any advantage in having twin points as opposed to single
the particular unit is mallory with no vacuum unit... on offer for about $50
       cheers trev

ps   yes burnsy  it is the one you discovered...im asking for you, me & mark

[craiga]

Trev,

Dual points have the advantage in that the second set of points is set up to open a few degrees after the first set. This extends the dwell period - the time the points are closed - which in turn increases the energy built up in the ignition coil. This is especially useful in high RPM applications where there is a maximum requirement for ignition circuit efficiency.

I bought one of these coils new a long time ago and paid $200.00! I would reckon $50.00 is a bargain, but to be honest I would spend my money on a late black motor electronic dizzy and coil. No points to muck around with, and a consistent dwell setting.

Cheers,

Craig.

[robbzfc58]

thanks craig  you confirmed my thoughts
      trev

[fastjbav6]

Craig i think you mean the Blue Motor elec dizzy, the black motor dizzy is a EST unit with an ECU.

Seb

[craiga]

Seb, you're right, it was the blue motor unit I was referring to.   But could you also use the dizzy from a non-EFI black motor? Did these have the Electronic Spark Timing feature?

There's an interesting story on OldHolden.com about fitting aftermarket electronic ignition to a Red six. Have a look here http://gallery.oldholden.com/Installing-Electronic-Ignition?page=1

Here's a picture of the kit, story says $550.00 complete.


Cheers,

Craig.

[craiga]

Just did a search found the answer to my own question.  :-/

There are two different distributors in VK sixes. The 3.3 EFI engine has a unit similar to VC-VH-WB blue motors (except for its advance curve) and will work well in a Red 6. However the dissy fitted to the 3.3 EST (carby) motor had no internals. All it does is 'distribute' the high tension spark from the coil to the plugs. The coil is driven by a computer inside the car (similar to an EFI computer) which gets its timing info from a crank sensor at the rear of the motor sensing the flywheel rotation. So unless you fit all of this gear, the dissy won't work in any other car.

[nicko]

just a small note  ::)on twin point dizzy's ,try and find a mechanic who knows how to set them up these days,
GOOD LUCK,we just sold one as after taking mates Hi Lux with 308 engine to the local mechanic and watching my mate fork over $300 for the install of said dizzy,and playing around with it for half the  day at $50 an hour,we went and picked it up and after 5 minutes car was boiling as it was way over advanced, took it back 3 times and had to pay more money ,i sold him a spare electronic one i had for my own project at the time,installed it for him myself in 20 minutes and it ran like a dream, found out later that he set points up with same gap and siad it should run fine,but he was wrong as there is a trick to setting them up and his books did not cover twin points,before i sold my elec one we rang at least 6 other mechanics and none of them could or would look at it,unless he was  prepared to leave car there for a day or two,(no thanks)so even though they can be a great performance part finding anyone with experience working on them these days is very hard at least in QLD country towns.

[fastjbav6]

Its been a while since i've worked on a black VK EFI motor, correct me if i'm wrong but i thought the dizzy was the same as the EST carby motor.
They both got an ECU, a sensor at the top of the bell housing as a reference point for # 1 cylinder, only a rotor in the dizzy (no other moving parts).
I agree that the ignition timing advance curve would be different.
I know of many VK's that have had the earlier electronic dizzy fitted due to the cost of replacing the ECU.
I would fit a dizzy from a VC, VH or WB with a new Transformer ignition coil to the red motor, the coil is better than the original or replacement oil filled electronic ignition type.
As for a twin point dizzy there should'nt be any thing hard about them.
It was all the rage in the 1980's to have a twin point.
I use to set the points at 0.016 thou on a V8 and set the timing anywhere between 6 to 16 degrees advance depending on the size of the cam and carby.
Some of the Datun 180B's had a twin point dizzy fitted from factory.
As the points got expensive we converted them to standard points.
There is also an after market electronic ignition conversion, its called Igniter and fits to the existing points dizzy.
You remove the points and condensor,change the coil and fit the new parts where the points use to be.
Don't know the cost  but i'm sure a lot less than a $200 second hand unit.

Regards  Seb

[Dr_Terry]

Hi Guys.

Sorry seb, this is a common misconception. The VK carby motor uses the EST system with the crank sensor off the flywheel, whereas the VK EFI motor uses a normal VC/VH style Bosch electronic distributor with its own specific advance curve.

The VK EFI computer only controls fuel & has no control over spark or spark advance. The VK EST (carby) computer only controls spark advance & the carby controls the fuel.

On the subject of Mallory twin point dissys, the best way to set them up is to set the dwell of each set of point separately & then check the total (combined) dwell. This, of course assumes the dissy has its advance curve set for that particular motor in the first place.

Where most people go wrong with distributors (& Mallorys in particular) is that they must be curved to suit the motor concerned. Cam size, manifolds, heads, carbiies, compression, fuel octane, trans type, vehicle weight & gearing all come into calculation. The Hi-Lux dissy mentioned by nicko in the earlier post is a good example. Unless the mechanic concerned had access to a distributorgraph, he could spend 2 days on it & still would not have a clue about the amount & rate of distributor advance, which by the sound of the end result, was way too much.

Another problem with Mallory twin pointers is that most are sold without vacuum advance. This is OK if you are racing & have a wild camshaft with no low-down torque & poor driveability. Most of our cars are street driven & require a bit of driveability & economy which is exactly when vacuum advance is required.

My workshop is in Sydney, I do have a distributorgraph & if anyone requires dissy work or help on this subject I  am only too happy to help.

Regards.

Dr Terry.

[nicko]

Dr Terry,thats my point,the local mechanic if he was honest ,would tell you that he does not have the gear to do job,also i have had twin points on cars with stock and with hot engines before when living in Victoria and found they worked very well and kept there settings for ages,but my mates could do them.which made life cheap in those days.