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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - programmable ignition

Has anyone tried this system ?

http://www.aldonamethyst.co.uk/

looks good to me,, thinking of giving it a go to see if it improves my ignition any.....
its cheaper if you go through simonbbc....

Andy


Andy Phillips (frankenfrog)

why not http://www.scparts.co.uk/sc_en/warehouse/tuning-internal-and-external-fixtures/car-electrics/distributors-and-electronic-ignition-systems/123-ignition-tune.html

More expensive but you ditch the old worn distibutor, have no loose boxes and tunable on the fly instead of when the engine is of
Onno K

Andy
See Classics Monthly January 2014. They have a substantial article concerning the fitting of the Aldon programmable ignition to a midget and a TR6. The article covers fitting and additional issues as well as the outcome (longer torque curve for the Midget). I think in a follow up the staff member with the Midget reported some adjustments that improved matters further (the Midget features in 'Staff Sagas').

While their kit may be OK, personally I would not trust Aldon with my car as last time they had it on the rolling road they made it run worse than before (something rectified by a RR session elsewhere).
Chris Hasluck

my thoughts are to follow this procedure below which i got from the excellent datsun1200 site... note that references to A-series are datsun a-series, not Austin...

its possible using this Aldon unit to have a switch on the dash to switch between two different spark curves...

so in theory (please dont be afraid to tell me if i'm wrong!) you could have a curve programmed to run on E85 petrol (available here, 85% ethanol and cheaper by 30% than other fuel and around 100 octane but only available at certain places) and another one for the more normal E20 91 octane....

plus of course being able to adjust the spark curve from your car without having to experiment with weights and springs etc makes it much easier..


Determining Optimal timing

One method you can use to determine the total advance your engine can use you can do at home. Be sure to use a quiet exhaust system so you can hear detonation (or use Detonation Cans, search google for this).

First set it the base timing to stock specification, and plug the vacuum advance line while driving the car.

1. Get the engine to 4400 RPM then floor the throttle and ensure it does not ping. If you use the lower gears (2nd or 3rd), going up a hill will put a good load on the engine. Be careful not to exceed speed limits or put pedestrians at risk.

2. Now advance the timing 2 degrees and repeat the high RPM load test. Listen carefully and do not let it ping for more than it takes to hear it. If it does not ping, repeat Steps 1-2.

3. If it pings, retard timing 1 degree and verify that it no longer pings. Congratulation, you have found the maximum timing for your engine. Make a note of this setting. Better yet, degree the crank pulley and find the total advance figure.

Now it gets complicated. The mechanical (RPM-related) advance curve may be too quick or too slow for your engine.

With the timing at your "optimum max", repeat Step 1 at various lower RPMs. Try 400 RPM increments.

If you find an RPM at which it pings, the 'curve' is coming on too fast.
If it doesn't ping at any RPM, the curve may be too slow. You can determing this by advancing the timing 1 degree, and see at which full-load RPM it first starts pinging.

If needed, modify the mechanical advance curve.

Finally, hook up the vacuum advance hose. Now try some part throttle driving. If it pings at any point, the vacuum advance curve is too much. Modify the vacuum can as necessary, or at least back off the timing until it no longer pings.

Note that using high-octane fuel may allow the timing to be advanced 1 or 2 degrees further than regular fuel.

Also differences in the A-type cylinder heads will make a difference. Quench heads (closed chamber) can a take a bit more advance. Open chamber heads may ping sooner and so need to be less advanced.
Andy Phillips (frankenfrog)

Another down vote for Aldon here.

I took a Rover V8 Vitesse to Aldon years ago - first and last visit - I like the look of the programmable ignition - but the Aldon logo puts me off.

I read the Classics mag article - and I'm fairly sure it said "disable the mechanical advance" - but it's at the GF's house.

If you can't get someone on here to confirm the article - i'm pretty sure there is a download option.
Malc Gilliver

This thread was discussed between 04/02/2014 and 05/02/2014

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.