Electronic ignition upgrade

[colin jones]

Hi all, this has probably been covered before but I'm not sure to what extent.
I think there was some talk about different length cam shafts for different distributors but I haven't found that. the first pic is the 2 bolt crab dizzy and the next is the bell style. the difference is the timing cover and the centre drive location. I'll load some more so you can see the difference.

[colin jones]

In the centre of the bell dizzy style is a location plug which comes out very easy which then looks exactly the same as the crab. As far as I know there is no electronic upgrade for the bell dizzy at this stage. So if you want to do the 12volt upgrade you will have to have a crab distributor. You can either buy the complete substitute or use your own crab dizzy and replace the points with the electronic points which are readily available from Macs auto. I'll get the part number and put it up for you.

[colin jones]

Here's a picture of mine. The original dizzy was blasted and painted. The new part comes complete with base plate and gaskets and there is no need for a magnet and you just use a standard 12v sport style coil and it remains the original look.

[colin jones]

The part number from Mac's Auto is # 47-68607-1 and it was $122usd + postage
I hope this is usefull and if I have pointed anyone in the wrong direction please let it be known.
Colin.

[jack neville]

There is units available for all types, crab, bell and Lucas from Jolley Engineering in the UK. Bu the price is a lot more expensive than Macs

[Ganmain Tony]

Great job Colin,

I'll certainly put that information to good use in the future..

Thanks for posting

[Tony Wheeler]

Originally Posted by colin jones

I think there was some talk about different length cam shafts for different distributors

Yes, the pre-42 camshaft had a longer nose to suit the diver's helmet dizzy. The post-42 camshaft had a short nose to suit the crab dizzy.

Aftermarket adapters were available to convert between the two types of dizzy, without having to change the camshaft. When converting a pre-42 motor to a crab dizzy, a spacer adapter was used. This fitted between the timing cover and the dizzy, moving the dizzy forward to accommodate the longer nose on the pre-42 camshaft.

When converting a post-42 motor to a diver's helmet dizzy, an extension adapter was fitted to the nose of the cam. This is the adapter seen above. In other words, it's a post-42 camshaft adapted to suit a diver's helmet dizzy.

Of course, it was also necessary to change the timing cover, because Ford changed the bolt pattern as well as the camshaft nose.

It's unclear to me why Ford made these changes. It would have been much simpler to design the crab dizzy to fit straight onto the pre-42 motor. It's as if they went out of their way to prevent interchangeability.

[Private_collector]

Macs prices are fairly mild, but their international shipping prices are huge. Anything bigger than a thimble coming into Australia, can expect an average of $60 or $70 for a box 2/3 the size of a shoebox.

I bought my electronic conversion kit via ebay. Purchase price much the same as Macs, and postage considerably cheaper.

Its not just 12v available either, mine is 6v positive earth. Same branding as sold through Macs.

[jack neville]

I have found that also with parcels from the Sates. They love taking really small items and putting them in really big boxes just to fill them up with lots and lots of foam pieces. Most of the time I am buying in breakable items that only need wrapping. Love to know how many cubic metres of foam and air each FedEx plane carries.

[colin jones]

Well after accidently putting a hole in my radiator while trying to get the fan shroud out and a fair amount of cursing and that's because I thought I could just do the job on the carrier without taking much apart. (WRONG) I had to take the radiator out to repair it and that was so much easier to change the timing cover over. I found that I needed to make a spacer plate that is
3/8" thick because the back of the crab dizzy is longer than the bell. The button extension in the picture above is not the correct part as you "WILL" need that spacer. They probably are available from the speed shops but I made a very basic one from a piece of 20mm plate. You learn something everyday. It will all be worth it at the end of the day!

[Tony Wheeler]

Originally Posted by colin jones

I found that I needed to make a spacer plate that is 3/8" thick because the back of the crab dizzy is longer than the bell.

Colin, you don't need a spacer, you just need to discard the button extension. You only need the spacer if you have a pre-42 camshaft. Your motor has a post-42 camshaft, so the crab dizzy will fit straight on. Someone in the past has converted it to use a divers helmet distributor, by fitting the button extension. You just need to undo the conversion by removing it.

[colin jones]

Hi Tony and thanks for the great information. I do in fact need the spacer as my engine is a pre42 model. The engines that I posted are just a photo of a couple of engines I have for parts. The carrier I'm upgrading has its original engine which does need the spacer.
I'm sure this thread will be an invaluable source of information for many in time to come. I've certainly learnt some future time saving lessons here.
Colin.

[Tony Wheeler]

Sorry Colin, I assumed the motor was the one with the new timing gear. I should have known you'd be on top of things! Nice job on the spacer BTW, I had a lot of trouble finding one last year. No one had ever heard of them, until finally I got onto Mike Davidson of Flatattack Racing in SA, who still had one lying around. I have an earlier type on another motor, it's cast alloy and shaped like the gasket. No doubt these were common in the '40s and '50s for rodders converting to crabs. I haven't come across the button extension before but I knew of their existence. They'd be quite rare I imagine, as very few rodders would swap a crab dizzy for a divers helmet. I suspect they were used when fitting a post-42 race camshaft into a pre-42 motor. I notice there's a stamping on the nose of that particular camshaft, which is what the racers did when they ground special cams. They used their own codes so no one knew what grind they were running! I wonder if it's a reground camshaft, they often made their way through several race motors as each one blew up!

[Lew Skelton]

Funny how things happen at the same time either side of the Tasman! I picked up a mallory electronic ign kit from an ex army landrover v8 a while back, i was looking at it and thought that with a bit of jiggery pokery it could be made fit into my crab dizzy, so pictures would be handy at this point but buggered if i can find the camera. Basically i cut the head off the landrover dizzy turned the housing down slightly on the lathe at work, cut the shaft and slotted it into the crab housing. Ill track down the camera and post some photos.

[Lew Skelton]

I finally found a camera, also basically finished the dizzy. I had to limit the total advance as it was about 24 deg. Fitted and test run today, ill need to tidy up the leads but otherwise sorted. Here is a pic of it in the vice prior to fitting.