Distributors

[Wigeon Incognito]

Do 'performance' distributors really make much difference and if so what difference do they make?

I only run a standard MG 1275 A+, not a road/race rocket but my current distributor is faulty and I was wondering whether the performance ones are worth the extra cash.

[eccles]

distributors are usually matched to the spec of the engine and the performance ones are usually designed to run in engines with a higher compression ratio and a wilder cam.
i'd just stick to the standard spec dizzy if i was you.

[love machine]

There are all kinds of old skool tricks to mucking about with the advance curve. Trickey does it well in his books, vizard doesn't. Aldon pretty much do a version of what old tuners figured out by mucking about. I can't remember offhand how you do it but it works for hairy cams, you set the idle at 1200 and get the smoothest idle you can, you then rev it until it detonates, you then file off the centrifugal weights until it stops, fit heavier springs first and repeat until you get no detonation. It's more complicated than that but I know a guy who built proper racing dizzies and I'm going to pick his brain as my advance curve is all to poo.

[Cooperman]

The Aldon 'Yellow' (for fast road engines) and 'Red' for higher spec engines are great. If you need more mechanical advance without increasing the static advance then Rob at Aldon will curve one to get it to match your spec. The one he did for me is super.
The problem with the dizzy, if you use the one without vac advance, is that with the advance set to otimise top end there is too much static advance to turn the engine over to start it, especially when hot. On my 11.2:1 c.r. engine I needed an extra 4 degrees of mechanical advance to get it all right.
To do your own is possible, but really you need a dyno to set the full advance, then you file back the cam to give the static figure you need. You may also need to use different springs, which is why it's difficult as a d.i.y. job.

I hope this helps,

Peter