Wanted Distributor B20B Engine

[lelshaddai]

My PV544 has a B20B engine in it. This is the distributor in it and have been advised that it is not correct. With this type of dizzy(retard) I cannot use vacuum advance(is is disconnected and plugged) What is the correct dizzy that should be in it? Second does anyone have one for sale?

[Ron Kwas]

lel;

You don't need vac advance and certainly not vac retard...leave the Centrifugal Advance in that Dist anyway, and you'll be fine...just plug that hole in Dist, where Vacuum pot used to sit...there's no need to over-engineer this!

Cheers

[lelshaddai]

Right now the vacuum pot is still attached and I plugged the connection hole. Is that OK or do I need to remove the whole pot and cover the bigger hole. It really runs rough until it warms up and even then it shakes a little at idle. I have tried numerous timing changes and they do not seem to help. I have rebuilt the carb and tried different jets and that does not seem to help. She seems to run rich and idles(diesels, run on) when shut off. Weber 32/36 carb.

[mocambique-amazone]

Don't remove the vacuum pot Lelshaddai. The plate with the contact on will move otherwise.
Does the centrifugal system work and come back?

I will check the number of this dizzy later, regards, Kay

[lelshaddai]

OK, timed to 10, idle is 650. Major dieseling (run on) after shut off. After it warms up. Hot here today. Run on is Worse than before. Actually keeps running. Running 160/165 in the jets. Can timing cause run on? The car is off. I have seen too lean or rich can cause run on. Which is it? Which way do you turn the mixture screw to make it more lean on the Weber 32/36? Are the jets correct size?

[Derek UK]

Certainly looks as if it needs a good clean out. It all comes apart easily and then you can inspect the weights and springs. Get some oil on the felt pad below the rotor, that looks dry and that oil lubes the shaft bearing.


B20B - 0 231 146 099 (B20B Amazon in parts book)
However, your engine might be from a 140 and that will likely mean a different Bosch number. Do you know what car your engine came out of? I think you may have mentioned this.

[lelshaddai]

It was from a 1969 144s. B20B

[lelshaddai]

Timing now does from 10 at 650 to 35 at 3000.

[swedishandgerman]

That isn't the correct distributor for a 1969 B20B from a 140. It would have had an 078. From '72 to '74 it would have had an 099. That's for Europe, but I know that there were others fitted for other regions where exhaust emissions regulations existed.

Based on achieving a range of 10 to just 35degs, I would say it might be one of these.

Sorry, but I have no information for an 086, so I am unable to tell you how to set it up and I have no data on what timing shoudl correspond to your Weber. However, for a standard '69 (assuming you have the standard cam as well):

• Dwell should be 62degs +/- 3
• Idle (670 - 77rpm): 11.2 - 12.8
• 970 - 1600 rpm: 16.2 - 26.7 degs
• 1450 - 2,100 rpm: 24.2 - 35.0 deg
• Above 2550 48.3 degs.

I have always considered to myself that full advance on these distributors is massively higher than others which is more like 40 max.

I've found these engines are super sensitive to run on and after tedious incremental adjustment on my P1800S, I have finally sorted it out. It is ultra sensitive to mixture at idle.

As well, all of the above settings are sensitive to mixture, so if the mixture is wrong, the combustion will be wrong and so the timing of the spark will be wrong if set up as above.

My advice is that you have to have to sort out your mixture problem. I don't know about Webers and the jets, so I can't advise. However, just incrementally adjust the mixture screw until the engine runs the smoothest. If it's lumpy like you say, it's probably rich or massively weak.

My thing runs on like hell if it is weak.

I can set mixture by ear because I have been doing it for years. However, for mixture at idle, I really recommend a Gunson Colortune. Gunson recommend a very blue appearance down through the tube, but I find B18 and B20's idle best when the flame just turns from blue to red as you screw out the mixture screw. It's at that precise point that I have completely eliminated run on in my P1800.

However, regarding that distributor: you can't run it without the vacuum can connected otherwise the points base will be loose. I would say that at the timing you have set there, that should run OK. I don't care too much about advance at idle myself; it really doesn't make much difference at all. But I am very into advance at full! As such, I set the timing to just above 40 degs (my cars are B20A and B18B) - it will pink under load. Then I incrementally adjust it back until there are no signs of pinking. As it happens, that usually corresponds to the book data, so confirms it's right.

[lelshaddai]

Thank you for all the data and information. I will work on it again today. The funny thing is have not got it to ping yet. Even when I had it at 20 degrees at idle and revved it up. I am starting to agree that this may be more of a carb issue. I can turn the idle mixture screw all the way in and the engine still runs. I am going to take her apart and check the needle and float level. I also checked for vacuum leaks and could not find any.