S122A project commencing

[Eccentric shaft]

New BLUE 8mm ignition cables on the way. A kit, so we can get rid of som excess cabling as well. Should tidy things up. In the meantime, thinking back on how things were when the sun was shining brightly — and AO Herschel Orange looked nice and deep in the evening light.

[Eccentric shaft]

How did this happen? No wonder the engine doesn't run properly when lead is engaged. The lead distributor (right in 1st photo) is completely off range! Easy enough to sort, but how did that happen? After barely 2000 miles? 

An old pic with the correct alignment added below.

No signs of slack in the distributor axle, so just hoping there'll be no nasty surprises when I dismantle the thing! 

[Casey]

Stunning pictures 

Strange about the distributor rotor movement - interested to hear if you find the cause.

[Eccentric shaft]

Yep – the top distributor was one notch off position. No loose bolts or any slack in gears. Could see no visible damage anywhere. So the mystery remains. I'd like to believe my engine builder when he says he did everything right, but more than that, I'd like to be able to trust this will not repeat itself!

Pics below of the base before and after reset, plus the present, correct angle of the rotors.

Set ignition as well as I could by ear with the engine still fairly cold. Idle a bit rough (but then again I have practically no resistance in the exhaust these days -home-made manifold and melted rear silencer- so that might affect how it's running). No rougher than before, anyway.

Starting and re-starting was a bit more difficult, too. On first test run I got some scraping noises when giving it some wellie uphill. Hard to locate, since road was wet and there was loads of ambient noise. Could have been an ignition box struggling (I hope).

Then swapped the cables for the MSD boxes and did a second test run. This time the car ran really well and no ugly noises to be heard. Pulled much better from low revs, and had plenty of pull on 2nd gear (couldn't give it more beans because of city speed limit). Much less splutter when braking on 2nd gear downhill and no delay on throttle at all. Seemed easier to re-start as well. Could be the MSD-boxes needed time to reconfigure, I'm not sure how they work in that respect.

Anyway, I did check the angles of the rotors on the timing mark after the drive. No sign of any changes.
We'll see how it behaves at cold start tomorrow and take it from there. Then fit new ignition cables before fine tuning with lamp.

[Eccentric shaft]

Sorry, your probably fed up with distributors, but the ignition mystery continues. Found an old Trail distributor and checked it against the one on the engine. Cam angle is identical. So nothing funky with the distributor, then. Then re-set the base back from 51 to the correct 34 degrees. And guess what: the rotors now align perfectly (see below)! Don't ask me how!

So far so good. But the angle was definitely off earlier and I have photos (and a witness!) to prove it. It might look like there's some wear in the middle of the brass base, as if a distributor has slipped at some point in the past. But nothing at all was loose upon first disassembly, so it has to be an old mark.

Haven't test started the engine yet. I'm waiting for my new, bespoke, 8,2mm ignition cables to have shoes fitted – and only then. 

[Jamie R]

Definitely not sick of distributors, it just over my head lol


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[Eccentric shaft]

Well, now I'm sick of distributors. Especially my trail unit. Got new cables fitted today. Look very nice. Everything correctly aligned. I tune the ignition by ear and set off up the hills (MoT due tomorrow, so early rise). Fortunately I'm nearly home when the spluttering returns. Manage to coax home with a couple of roadside tinkerings.

NOW i FIND the cause. Yes, it is mechanical. The distributor axle simply doesn't reach far enough into the socket, so it slips. Even when everything is nicely tightened up, I can turn the rotor around by hand with just a little bit of force. Once loose, it keeps slipping and sliding.

So now looking for a new trail dizzy, a new trail dizzy socket, and going for MoT on the lead circuit only. Should probably warn my mechanic to wear a gas mask tomorrow! 

As you say, Clive, giving up is not an option! This will be sorted. How much is left of the season when that happens is another question...

[Jamie R]

https://fullfunctioneng.com/product/12a-trigger-hall/

Bought one of these today 

Bet it dont help you tho


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[Eccentric shaft]

Thanks, but you're right, Jamie. Not compatible with twin dizzy. On the upside, I won't have to buy the whole lump and spend loads. Should be enough with a new/better brass rotor base and a new/better (correct) cam for 12A trail dizzy. My engine builder is looking through his stock of leftovers atm.

Another "upside" is I have to learn how to dismantle, overhaul and reassemble distributors with all their tiny shims and whatnots. The stream of forum posts should be secured for a while... 

[Jamie R]

Twin dizzy ..... now youre just being greedy. Lol
Im sure if it ran a modern ecu you could tandem the signal etc  or wasted spark yadda yadda .
Either or new skills is always great


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[clive]

This picture may help.

The vacuum pots now look in the right position, so you only need a strobe light and the pointer should then start lining up with the red and white marks on the pulley.

Try and get you money back for the wheel kit as you need an ECU to make this work.

[Eccentric shaft]

Thanks, Clive. Yes, the vacuum clocks are a good indicator, but not when the trail cam disengages from the socket and starts doing its own thing. Then every new rev potentially comes with its own unique ignition timing! The clocks don't budge, but I can promise the rotor position does. It's  dancing all over the place. 

And Jamie, I can tell you're now intrigued by the twin-dizzy magic, so consider this: The trail distibutor cam rotates anti-clockwise, the lead distributor cam rotates clockwise. Each of them are topped by a two-headed rotor (yep, that's a lot of sparks). Nonetheless, the lower cable from each distributor cap goes to rotor one, the higher cable to rotor two. At this point you can already see faint blue smoke coming out of my ears. How are yours doing? 

It seems the problem at hand is to be found in the sockets. At least they make perfect mechanic sense...

[Eccentric shaft]

Had a spare Hella 170, I thought. And was looking for a match. And this guy had a 170 for sale. Turned out mine was much bigger (a 190 or maybe even a 200). So I still have that lonely single lamp. But now I also have a pair of stunning Hella curve lamps that the same guy also had for sale (unused, in their original boxes). To hang from beneath the bumper like on this Rx3, I suppose. Dunno why I ended up buying these –apart from the fact that they looked great– we don't get much darkness in classic car season up here in the arctic. But at least it's nice car jewellery... 

[clive]

Wow what a nice RX-3

[Nightfire10]

Had a spare Hella 170, I thought. And was looking for a match. And this guy had a 170 for sale. Turned out mine was much bigger (a 190 or maybe even a 200). So I still have that lonely single lamp. But now I also have a pair of stunning Hella curve lamps that the same guy also had for sale (unused, in their original boxes). To hang from beneath the bumper like on this Rx3, I suppose. Dunno why I ended up buying these –apart from the fact that they looked great– we don't get much darkness in classic car season up here in the arctic. But at least it's nice car jewellery...

Very nice

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