points and timing

[russelljones48]

I've read all I could find here on this topic and would like confirmation some of the data if the techies (or not so technical) can help out.  I have to admit that I'm a bit confused   

Here's what I think is correct for my car/distributor: 1967 230SL 2.3L L6 Distributor: 231 116 051 vacuum retard

point gap: .012-.016"
timing: 8 degrees BTDC @ idle  with vacuum line disconnected (this doesn't seem right with a vacuum retard system)
timing: 30 degrees @ 3000rpm
idle speed in neutral: 700-800

dwell is assumed to be 38 degrees based on other similar L6 Mercedes from the same years?

I did measure dwell and it's @ about 45 degrees so it looks like the points aren't gap'ed correctly.

I would also like a pointer to the correct shop procedure for setting point gap and timing - I couldn't find that specific info either.  I can figure this out but it would be nice to actually read the MB shop procedure if it's available.

[Benz Dr.]

A lot of people get confused by this sort of data. Set your distributor to 8 degrees BTDC with the vacuum line connected. Timing at 3,000 RPM should be about 38 degrees. The 30 degrees BTDC at 3,000 RPM is how much the distributor advances and once you add 8 degrees from idle timing then you get full advance. Disconnecting the vacuum line and then setting your timing to 30 degrees will give you the same results as long as the vacuum system is working.
Opening the points lowers dwell angle and closing them increases dwell angle. Changing the dwell angle or point gap changes timing so you may need to make a small timing adjustment if you changed your point gap very much.

I do all of this set up on a distributor tester but you will have to do a basic setting to start with and then make smaller adjustments with a dwell meter after you have your engine running.

[russelljones48]

Thank you.  That's what I need confirmed.  I am curious though - is that 051 distributor vacuum retard or advance?

[dirkbalter]

Is a "retard" distributor, check below.
https://www.sl113.org/wiki/Electrical/Distributor#Advance

[Pawel66]

Struggled some time with 051. Ended up buying 123 and setting it as per BenzDr and other Members advise. Happy since then. Original 051 wrapped on the shelf.

[russelljones48]

Thanks to all for responses.  the last pointer to content is greatly appreciated.  I'm not sure why my searches don't produce the desired content but that's pretty much what I was looking for.  And it confirms that I have an 051 vacuum retard distributor and it's the right one for my car.  I am not having any real problems with it so my plans are to upgrade to the Pertronix "points", open the plug gap, and see how it runs.