Webber DCOE-45 + 123 ignition/vacuum advance

Technical MGB discussion
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Posts: 56
Joined: Mon Jun 25, 2018 2:04 pm
Forename: Harry
Surname: Bukin
Location: Devon

Webber DCOE-45 + 123 ignition/vacuum advance

Post by Hazza1190 » Mon Nov 02, 2020 11:49 pm

Hi Guys,

Its a little way down the road before I'll need to actually implement this; but it has been bugging me and I'd like to know your thoughts.

Basically, I have a Webber DCOE-45 carb and an early 123 ignition which has a vacuum advance pickup.
Should I worry about the vacuum advance? Or is it worth tapping into both sides of the manifold then running to a y piece, then into the dizzy?
I could just run to one side of the manifold, but could that cause issues with having only alternate induction pulses?


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Peter Cresswell
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Re: Webber DCOE-45 + 123 ignition/vacuum advance

Post by Peter Cresswell » Thu Nov 05, 2020 10:54 pm

Hi Harry
If the distributor has vacuum advance you will need to connect this up otherwise you won't get enough advance when the engine is pulling hard. Try contacting 123 ignition systems about where to take the vacuum from. I think they are in Belgium but see here https://www.123ignitionshop.com/gb/contact-us
1969 MGB Roadster
2020 MG HS Exclusive
2007 Mercedes SLK
Plus 34 other cars since 1965

Vic Butler
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Re: Webber DCOE-45 + 123 ignition/vacuum advance

Post by Vic Butler » Sat Nov 07, 2020 11:57 am

Don't take the vacuum advance pick up from the inlet manifold as rubber bumper B's had. It needs to be on the air filter side of the throttle disc close to the disc.
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine

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