123 RV Distibutor with vacuum retard Venturi , how do you set it up ?

[Dave H]

 I’m trying to get the 280 engine running smoothly after rebuild.
 I now realise I have a vacuum retard Venturi and I’m struggling to get my head around it.
Is the the 123 RV distributor compatible with this or, do I need the advance type Venturi ?

[Pawel66]

Just place it and wire it as described and load the curve.

There are quite a lot of posts on this around.

You can take the curve from attachment.

[Dave H]

But isn’t the 123RV a vacuum advance distributor?
Surely it needs a throttle body with the vacuum connection on the air filter side of the flap, not the engine side ?
All emissions equipment is removed.

[stickandrudderman]

The 123 dizzy will accommodate both adv and ret throttle bodies. You just need to select the correct setting on the internal pot adjuster under the 8mm allen plug.
Personally I just use a strobe and keep selecting until I get the results I want as I've never found the suggested settings work for me.

[Dave H]

But isn’t the advance vacuum system better all round , retard advance was only ever an emissions fudge introduced to get around and meet ever stricter tests . 230s had the advance throttle bodies with the vacuum take off before the air flap. When all emissions equipment is removed isn’t it better to go back to an advance vacuum throttle body ?

[stickandrudderman]

Retard is only at idle.
All cars have an ignition timing of 38 degrees at 3000rpm with everything connected.

[Dave H]

Great info Pawel, Colin.
Seems I’m not the first (or will be the last) to fall foul of the timing retard/advance dilemma!
Dave