Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: Tom in seattle on May 10, 2018, 00:15:12

Title: Ignition timing for 250SL
Post by: Tom in seattle on May 10, 2018, 00:15:12

I have a European 1967 250SL.  It has a 051 Bosch distributor.  The tech manual indicates this is a proper distributor but possibly a 009 distributor may have been substituted by recall later.  The 051 may have a retard mechanism built in, I'm not sure.  I'm hoping someone can tell me how to time this distributor which is using a Pertronix trigger instead of mechanical points.  How many degrees before or after TDC?  With vacuum tube attached or without vacuum?  It seems that the 230s and later 280s may be timed differently due to the distributor used and with or without the retard feature.

Love this site.

Title: Re: Ignition timing for 250SL
Post by: Tyler S on May 10, 2018, 02:56:16

The 051 distributer is timed with vacuum line attached. It makes no difference having Pertronix or regular points.

The spec is to set the timing to 30 degrees BTDC @ 3000 rpm. However these engines do much better when set to 35-38 degrees BTDC @3000 using premium fuel.
Dont worry about setting timing at idle. Just let it fall where it may.

Title: Re: Ignition timing for 250SL
Post by: Tom in seattle on May 10, 2018, 21:51:55

Tyler S.  Thank you very much.

Title: Re: Ignition timing for 250SL
Post by: Benz Dr. on May 10, 2018, 22:33:11

I like 38 degrees BTDC @ 3,000 RPM. Most engines run just right at that setting. If your distributor is set up correctly, you will get 8 degrees BTDC at idle.