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MG MGB Technical - Distributor

is there any information about quality or faults on Accuspark and/or Powerspark distributors? GHD5 needs a new one.
Siggi
GHD5

Hi Siggi.

I fitted an Accuspark 25D to my 1970 BGT recently, and have had no problems. I must admit I have not done many miles, but it starts within 2 turns of the motor when cold and when warm it starts first turn. I was lucky as it was on special at the time and I paid £50 for the new electronic distributor. I have no doubt it was made in China, but the quality looks OK.

Ronnie
RA Potter

Fitted one to a standard road car with good results. Much better than points for not much money, and good service from the company also.

Jim
jim soutar

a B owner I know bought the £77.50 AccuSpark kit (electronic dissy, sports coil, universal HT leads, 'red' rotor arm and plugs) he's not fitted it yet as far as I know but said the HT were flimsy connection - but some thing's got to give at that price

many seem happy with the Powerspark igniter heads

I've only had Lucas and Aldon igniter heads fitted to the existing dissy but both worked really well but not as well as the 123 fully electronic dissy (but that's another price league)

Nigel Atkins

Thanks for the information,just can't make up my mind...
Siggi
GHD5

I can recommend thoroughly recommend the 123 fully electronic dissy, it moves the car's running up a notch or two from idle all the way through the rev range, if the rest of the car's engine, carbs and ignition is in good condition it'll really make use of it

by better performance I mean better starting, idle and running - you could also improve your mpg but if you're like me you won't because you can't resist using the extra sharpness

here some excellent built and quality HT leads to also take advantage of the gains - http://www.performanceleads.co.uk/
Nigel Atkins

Hi Siggi

We are seeing one or three Accuspark systems fail after a year or so. Last Friday we had to swap an Accuspark to an Aldon Igniter on a Race midget as there was a miss-fire. We have had problems with the Accuspark plugs. As Nigel says, at such a low price one can expect something to give. Having said that, if the advance curve is ok for your engine on an Accuspark system you could fit 4 to the price of one of the better quality and suited to the job 123.

Peter
Peter Burgess Tuning

Hi Peter,
originally I'm after a Lucas 25D4 40897 but so far with no success. Don't like 123 for that money I can have a dizzi build from Martin.
Siggi
GHD5

hasn't Martin any core?

Peter
Peter Burgess Tuning

Peter, while we are talking about distributors, have you any experience of the Aldon Amethyst programmable system http://www.aldonamethyst.co.uk/ This is likely to be a more robust build quality than the Accuspark components isn't it, and a bit cheaper than a programmable 123 dissy?
Mike Howlett

If only it had knock retard ...

How does it cope with the distributors in-built centrifugal and vacuum advances? Easy enough to disable vacuum, and the vacuum signal has to be diverted to this unit anyway it looks like. Do you have to dig in to the distributor and lock the centrifugal?
Paul Hunt

That's right Paul. Aldon supply a strap thing to prevent the weights from moving. On the Accuspark programmable system they tell you to tie up the weights with stainless locking wire.

To give you knock retard wouldn't it have to have some input from a knock sensor on the cylinder head? I believe that's how they do it these days.
Mike Howlett

Knock sensor - yes, but they are cheap and easy to get. I've just got one from a scrapper and fitted it to the roadster to record and analyse some signals. There is a very convenient mounting point under No. 2 plug using the upper tapping for the rear dynamo bracket (on engines with alternators) using a 1/2" AF bolt.
Paul Hunt

Hi,

I have been using an Aldon Amethyst for the past 2 thousand miles on my 77 mgb and am most impressed. Before installation, I used an advance timing light to obtain a footprint of the distributors advance curve which I used as the starting point for the Amethyst. The distributor mechanical advance mechanism has been locked using springs. I have since modified the Amethyst curve to give more advance at the bottom end and also re-scaled the vacuum advance and found that the car performs noticeably better, still without pinking. It pulls more strongly at low revs and even the fuel consumption figures have improved. Perhaps one day I will be able to get it onto a rolling road and take full advantage of its settings flexibilty. The Amethyst Aldon is very easy to program and with the module mounted inside the car I am able to make changes from the driving seat.

Phil
P Allen

Thanks Phil, its good to hear feedback from a user. I am thinking about one for the Elan Sprint I am rebuilding. With its high compression engine, spark advance is critical for using modern fuels.
Mike Howlett

Hi Mike

I haven't tried the amethyst yet or known anyone withone.

Peter
Peter Burgess Tuning

This thread was discussed between 23/08/2013 and 04/09/2013

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.