I have been told of recent that you can do up your current dizzy for curve to give more power? does that sound right?

i don't really understand this could some one explain.

i got a quote of $180 to do my rover one, is it worth it?

thanks for your help.

If you've modified your engine (head work, cam, carbs, etc) then it may well benefit from a different advance curve. If this is the case, then yes -- recurving your dizzy is a good idea.

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Simon

The adventures of an owner builder in the Tallarook Ranges

so what does it do?

what about them 123 ignitions?

When you change the performance capabilities of an engine, it will often change the position of the piston at which the spark should be generated for maximum power. Usually on stock engines, more advance is required (that is, the spark is fired further before top-dead-centre) in order for the flame front to generate maximum push on the piston on its downward stroke.

When you improve the volumetric efficiency of an engine (with head work, a cam, etc.) you will need less spark advance to generate maximum power. This means your dizzy will need to be recurved so that it produces the spark at the appropriate piston position before TDC.

The 123 dizzy is convenient in that it has 16 advance curves pre-programmed (4 variations of 4 curves) which means you can get the advance closer to ideal than with a standard dizzy which has not been recurved. It's not perfect, but unless you have access to a dizzy machine (or a mechanic who does) it's the next best thing.

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Simon

The adventures of an owner builder in the Tallarook Ranges

ok i see.

i cant get it sent away and re curved he said to the same spec as cooper s.

not sure what to do really.

will it be ok to drive the car see how it runs then do the curve thing after?

You could send it off and get it recurved, but who says the Cooper S curve is right for your engine? Unless you put it on a dyno and find out, it's all guesswork and you might as well do nothing. This is the attraction I have to the 123 (I have one on my car) -- I can change the curve and decide which gives me the best performance.

In any case, you can put your dizzy on it and recurve it later no worries, all you'll do is not develop maximum horsepower

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Simon

The adventures of an owner builder in the Tallarook Ranges

ok great..

can you tell me did you notice a big difference in running with a 123?

i might get one not cheap though... gulp.

Firstly, they're exxy - $500. Up to you whether you want to spend that much, others will tell you a Pulsar dizzy is muuuuuch cheaper and gets more or less the same result.

That said, I noticed a huge improvement after installing the 123, but then my Lucas dizzy was probably in not-so-great condition. Things I noticed:

* Throttle response much improved, likely due to the engine getting correct advance at low RPM
* Idle quality much improved, chalk and cheese really. With my cam I could never get the car to idle below 1000rpm without stalling, now it'll sit on 800rpm all day (although I set it to 1000)
* Smoother revving all over, will rev all the way to BANG
* Powaaaaahhhhhhh I run mine on curve 6 (the third-most agressive street big-bore curve) and it's very noticibly faster than it was with the old dizzy (again, likely due to it being rooted).

The other big advantages with the 123 (and any other electronic dizzy) is zero maintenance -- I've not touched it in two years and it still performs. No points to wear out

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Simon

The adventures of an owner builder in the Tallarook Ranges

i think ill bite the bullet and get it.

i will wait a bit firstly.\

but what do i buy for A+
WITH VAC??? i dont even know what vac does lol..

i have twin su's

thanks for your help

No worries Seriously, do consider a Pulsar dizzy or (if your dizzy is in OK condition) an electronic module, those options are much, much cheaper and will get you within a few HP of maximum with all the other benefits of the 123. I like the 123 for its tweakability, I'm a fiddler

Next on my agenda is a Megajolt / EDIS setup so I can set the advance from my laptop

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Simon

The adventures of an owner builder in the Tallarook Ranges

but they look sexy as well.

Same deal, the only difference with an A+ is the physical dizzy mount.

Vacuum advance is really only there for fuel economy, it won't help produce more power. The theory is that with high manifold vacuum, there's less air/fuel mixture in the cylinder which makes it harder to ignite. The vacuum advance mechanism on the dizzy advances the spark in this situation so combustion has more time to complete.

Twin SU's won't change things in the slightest. What's good for a single is good for twins

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Simon

The adventures of an owner builder in the Tallarook Ranges

awesome!!!

added to the list.

If fitting a Pulsar dizzy don't just bolt it in there.. the advance curve is wrong. If timed right at max advance it will have too little advance down low. If timed to normal static timing it'll have too much max advance.
Send it to Graham Russell with your engine specs, and he can change the curve at minimum cost. Nothing like $180.
It made an enormous difference to my well modified 1360.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

There you go, best of all worlds

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Simon

The adventures of an owner builder in the Tallarook Ranges