No vacuum advance.

[Vic Butler]

I am going to disconnect the vacuum advance on my Stage 2 BGT as it would appear to be unnecessary and if there is an improvement I'll be having a spare distributor set up by the Distributor Doctor to suit the state of tune of the engine with no vacuum advance.
Just wondering if anyone has tried it and whether there was any difference.
. Vic

[Mnripley]

Vic, spoke to Peter Burgess about fitting the Aldon distributor with electronic ignition. Peter said not to bother with the vacum just set the car up without and find what’s best advance setting. Best way would be to put on rolling road to check it correctly. I found no problem without vacum car performed well.

Now back on standard setup as the electronic ignition was replace twice and then failed again. I sent the Aldon distributor down to DD to see if he could modify to take points but cant be changed also after 8 months of use play was evident in the bushes he couldn’t replace them as they are metric and the body is not lucas. Donated the distributor to his collection. Have now fitted Luminition in 45d4 unit working well but with vacum, thinking of going mappable so weights and vacum would not be needed.

[Vic Butler]

Evening Moripley.
Currently the MG has a 45D4 rebuilt about 8 years ago by the Distributor Doctor to suit the state of engine tune. I have disconnected the vacuum advance and advanced the ignition but have yet to road test. Lumenition Optronic is fitted.
I have ordered a second hand 45D4 from Andy Jennings and I will have this set up by the Doctor for the state of engine tuning but without the vacuum advance. I'll swap the Lumenition to it.
Unfortunately SRE who built my bespoke Downton spec head with MGC inlet valves have moved from Amesbury to Bristol and I never got around to having a rolling road session so at the moment it's down to marking the distributor body for a starting point and advancing the ignition little by little.

[Vic Butler]

In Peter Burgess' book on tuning MGB engines he states that the vacuum advance should be retained.
I contacted the Distributor Doctor today and he will convert my spare 45D4 distributor to a 43D4 without vacuum advance to suit the state of engine tune.