Sprint 123 USB dizzy

[Mahesh]

Removed the clamp from the car again, and joined up with the second clamp to check height, the pic was taken with the m6 bolts, now changed to m5 and nyloc.

[Mahesh]

The height was my main concern, which is now spot on as the plate mounting bolt heads are the perfect spacing height and keep the two clamps apart just right.

[Mahesh]

So to sum up, the bottom clamp is bolted to the engine, the top clamp to the bottom clamp, and the 123 to the top clamp, and once the timing is set, both nylocs and clamp tightened up.
I painted the drive gear silver, as I will remove after a couple of days to see where the gear contact point is.
The top clamp wings were drilled out to allow more movement.

[Mahesh]

And of course the car refused to start.

The main problem is that the 123 cap only fits in one way, so the whole dizzy was out by 180 degrees.
Another reason to going through all this clamp faff.

Managed to resolve by only plugging in leads to cylinder 2 and 3, and then 1 and 4 on the fly as the engine is on.
I did try the 1,3,4,2 following the cap and rotor rotation, but sod loves me too much and would not leave.

Anyway, car up and running, entered some values into the 123 this morning, running a bit better, have to
set the timing, and fully tighten up and tidy the leads.

Will know in the next week how it goes, all well, I may attach the adaptor made by Jeroen, and kindly sold to me
by Sprint95m.

[soe8m]

The reason why i used adaptors is that within time the gear failed on the jackshaft and dizzy because of not lining up properly. Left me with an oilpressure warning light on at the roadside many years ago. With the adapter the dizzy is centrated 100% and as for the height/depth of the gear the installer is responsible. Make sure the dizzy is centrated properly, is rigid and the gear has the exact depth otherwise things go wrong.

Jeroen

[Mahesh]

Many thanks Jeroen,

The gear height was my main concern, which is why I had to test with an adjustable
type rig. I still have to remove the 123 to check the markings on the drive gear.

But now that I have the measurements (template), I can attach the "fit once" adaptor,
adjusting height as necessary.

Also the timing adjustment was another point, the 123 sits at a very awkward
rotation compared to the original, with little movement available on the adaptor,
I now have a reference point to work with (hopefully).

[Mahesh]

Have asked a couple of metalworks in the area to see if a second adaptor can be made
( I just hate using up limited items ) all of them are quoting around £50 each

I have taken measurements and cut out templates, but for now it seems like the adaptor
has to go onto (into) the car, as I cannot take a risk on the gearing or other problems as
Jereon said.

Just ordered a couple of studs to attach to block and 123, as soon as they are
in, installation and tidying of cables can be finished and then back onto the carbs.

[dursley92]

Mahesh, I reckon I will be going the 123 route for my Sprint engine so could you do some more detailed pictures of the adapter please? I will get my local machine shop to produce one so any more information/measurements will be a great help.

[Mahesh]

Don't worry Russ,

I have asked the engineering firm to make an extra, measurements will be available.

Hope to also get the correct adaptor mounting height measurement, which as Jeroen has mentioned is crucial. The silver paint should have worn down by now as an indicator.

The aluminium billet needs to be at least 46mm x 70mm x 40mm (ish)
If that helps you get a pricing estimate.

With a bit of luck next week, should have the adaptor back.

[Mahesh]

Unfortunately the local engineering firm is very slow, but have assured me that they will prepare and get ready
the adaptor I asked for by this coming Tuesday.

In the meantime I have filed down another bush for the drive gear., a bit longer this time, and better done,
I could really do with a mini lathe.

[Mahesh]

Just thought I'd put a picture up of the closeset dimension off the shelf bush, and the diy reduction job next to it.

[Mahesh]

The cloning/breeding process seems to be a success,
will know for sure after fitting,

at the moment it seems like
a perfect copy when offered up to the original.

[soe8m]

Jeroen

[dursley92]

oooooh, looking good!

[Mahesh]

Unfortunately a good chest infection over Christmas had slowed down the works, however its now time to
remove the 123 from the car.

Set back to default, and removed the 123.

The silver paint has worn of in about the right position, with the adaptor in place is should go in about right.