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1973 distributor advance curve

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Denis Avatar
Denis Denis Hill
Bearii, Nth Victoria, Australia   AUS
Will What model of the 123 tune did you get the bluetooth or the USB type. I have the USB type and set the initial curve on the bench, with my laptop, even before fitting to the car. Then when fitted into the engine and the green light showing at TDC will position "all" your points correctly when running. I have not used the bluetooth type but the setting up is the same. When you do supercharge its five min to change. While I use the dyno for confirming results and fine tuning its not the best for advance curves as a lot of the points are below the dynos happy working range, not to mention, expensive. Have you downloaded the programme from 123 ? Its simple to use and as Scott said leave the vacuum advance until your happy with your curve settings and performance. If you have not yet fitted it, programme it on the bench. Denis



68 B roadster, Daffodil yellow, Moss supercharger, Burgess SC head, SC cam, Mikuni HSR 48 carburetor and engine built for supercharging.

73 BGT V8 conversion starting with a bare shell. Built the engine early in the year with high comp pistons and a few other nice but not too wild bits. Have completed the firewall and steering mods but it is a complete resto and will take time. I am however really enjoying this new project.

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willholmania Avatar
willholmania Will Holman
Peterborough, Cambs, UK   GBR
Thanks Denis

It sounds like you've built what I'm trying to achieve – I wish you lived down the road rather than on the other side of the planet!

I was wondering whether I could set the dizzy's curve with it powered up on the bench – I'll do that. It's a bluetooth version but as far as I know the only difference with your USB one is that I use an app on my smart phone to set it, whereas you use a laptop (I use Macs and only have a very old Windows laptop for other mapping duties).

I've got the following data for the Lucas 41288 distributor, which is what I will start with while my engine is still NA. Although I may tweak that to bring in the 22˚ of advance at 3000, raher than 2200rpm, as that seems to be acknowledged as a good idea.

Crank degrees advance/rpm
0 to 6 deg @ 600rpm
4 to 9 deg @ 700rpm
7 to 11 deg @ 900rpm
13 to 17 deg @ 1600rpm
18 to 22 deg @ 2200rpm
 
Vac advance
Starts at 5” Hg  (127mm Hg)
finishes at 13” Hg  (330.2mm Hg)
14 deg plus or minus 2 deg

Obviously this is all on top of the 10˚ static baseline advance figure.

When I get the blower fitted (I'm looking at having it on within the next few weeks), could you give me the data for what you've ended up with on your dizzy?

Denis Avatar
Denis Denis Hill
Bearii, Nth Victoria, Australia   AUS
Will, if you have a good look at the figures you posted in (17). with a 10* initial is very close to what I posted first up except it comes in a little earlier. Just because you have seven plotting points you don't have to use them all. Dont forget to also plot the maximum revs advance (the same as your curve maximum) Good luck and lets know how ts going. Denis



68 B roadster, Daffodil yellow, Moss supercharger, Burgess SC head, SC cam, Mikuni HSR 48 carburetor and engine built for supercharging.

73 BGT V8 conversion starting with a bare shell. Built the engine early in the year with high comp pistons and a few other nice but not too wild bits. Have completed the firewall and steering mods but it is a complete resto and will take time. I am however really enjoying this new project.

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willholmania Avatar
willholmania Will Holman
Peterborough, Cambs, UK   GBR
Thanks Denis. I've now established that with the dizzy set to TDC and the green LED just on, I need to add the 10˚ to each of the figures.

I'm still a little unsure of how to add the vac advance but I guess I'll get there. Seems like a good product, but the instructions need a lot of improvement.

Incidentally, mine comes with a base curve from a Peugeot 404 on it! I thought they were joking at first!

willholmania Avatar
willholmania Will Holman
Peterborough, Cambs, UK   GBR
Hi

We fitted the 123 Tune + last week and mapped it on the rolling road. With the mechanical dizzy swung as far as it would go, we got 82bhp. With the 123 we ended up with 88bhp. Seems a worthwhile fitment even with a standard engine, and it will obviously be a boon when we fit the blower.

Dandare Avatar
Dandare Danny H
Sydney, Australia   AUS
Will Holman of Practical Classics fame?

Danny

pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, Nova Scotia, Canada   CAN
In reply to # 3553347 by willholmania Hi

We fitted the 123 Tune + last week and mapped it on the rolling road. With the mechanical dizzy swung as far as it would go, we got 82bhp. With the 123 we ended up with 88bhp. Seems a worthwhile fitment even with a standard engine, and it will obviously be a boon when we fit the blower.

Wait 'til you fit the 123 with a set of mechanical breaker points... you'll get 3 to 5 more horsepower... devil smiley

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

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willholmania Avatar
willholmania Will Holman
Peterborough, Cambs, UK   GBR
That was many moons ago, David. I started Practical Performance Car 13 years ago, and have been running it ever since!

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