points and condenser for distributer 116 047 230 1966. Part numbers needed.

[Paul99]

Hi - been trying to find the right points and condenser for a 116047 distributer, 230 1966.

The points in it are ; 000 158 20 90 (merc number) and see ok, but don't seem to be the ones listed in the tech manual.

Anyone know the right merc part number for the points and condenser please for this distributer?

[DaveB]

try 000 158 16 90 and 000 156 71 01, from the edition B parts book

[KevinC]

Also...there are a couple of nice cross-reference tables in the Tech Manual...

http://www.sl113.org/wiki/Electrical/Distributor

[Paul99]

many thanks!    Changed the points last night as starting was getting a bit slow.  Started instantly. Old points badly pitted.  New ones made a great help to instant starting.  I guess a condenser either works or it doesn't?  Do they "half" work??

[garymand]

Well, not exactly.  They reduce the arc at the points as the open.  They are a bit tricky to understand and explain depending on your physics background.  They are the electrical equivalent of shock absorbers or vibration dampeners.  They help the circuit resist changes in current flow.  Starting with your points closed, the capacitor is shorted to ground by the points, (So is you coil).  The other siide of your coil has some voltage on it and the coil is "charging up" to that applied voltage. 

When the points open, the voltage in the coil wants to keep going to ground.  That's not good for your points becasue the voltage arcs and carries some metal atoms from one point to the other point.  voltage flows the opposite of what the original Phd's studying it thought.  It flows from minus to plus.  so your points should pit on the negative side and get a point growing on the arm side.  (they thought the flow was from anode to cathode and labeled them backwards. (I think I have that memorized right.) 

The capcitor is like two giant metal sheets with a thin sheet of plastic keeping thm from touching.  As the voltage trieds to keep flowing to ground, the electrons (not really but its a good analogy) are pushed through the plastic and cross over from the - plate to the + plate until there isn't enough electromotive force left to get them accross.  During this transfer of electrons, the arc at the points is miimized.  This type of capacitor doesn't normally wear out.  But the internal connections can open or the sepatating sheet can allow the plates to touch shorting the capacitor.  Its easy to tell if it is shorted, not so easy to see if it is open.  I haven't tried this for a long time, but I think you can quickly connect a sensitive ohm meter to the capacitor and see the needle twitch, jump, show some resistance that just as quickly goes away.   You are seeing the current flow.  Each time this happens, the current flows through the capacitor for part of the Dwell time.  If the cap is shorted, no spark to the plugs.  If it is open, big spark will jump at thed points and they pit real fast.  In 50 years of changing points, I've never changed a capacitor.  I've just never found a bad one.  Can't say that about many things....

[Paul99]

thanks Gary !  phew!  think ive got it now.  Its a long time since I have had a car with points (about 35 years!)  I do recall that changing the points on my renault8 back in the 70s' made it start much easier.

what I cant recall is how often to change them?  The last set in the pagoda lasted about 3k miles.  Would be interested to know how often in reality people change them and get better starting as a result.  the hand book says 6k miles.

[garymand]

I put in a capacitive discharge unit in about 1972.  I havene't changed points since.  I've seen some threads about whole new distributors, but there are point replacement things that replace your points and do the heavy switching with no wear.  http://www.amazon.com/dp/B001O28622/ref=asc_df_B001O286222772910?smid=A3GH90B530LQFY&tag=shopzilla_mp_1044-20&linkCode=asn&creative=395105&creativeASIN=B001O28622
Here is a CD ignition box that goes between your points and the coil.  No need to change points or coil the stock units are fine. 

[fmen3366]

Thanks, Gary for the CD MSD unit you mentioned above. Have you actually installed this unit in your car? I will be replaicing my points soon (have a 061 distributor on a 70 280sl) and would seriously consider adding this unit. Here's hoping it's a breeze to install.

[garymand]

I just checked and adjusted my dwell after having the CD ignitin in since 1972.  The dwell was 38!  that is at the minimum opening range.  Meaning in all this time and milage, the wiper have only worn from 40 to 38.  I opened it to 41.  (It is a jerky adjustment at best.  and getting exactly what you want is not easy.) 

Installing a CD ignition is easy.  Where to mount it is a different story.  Mine is attached to my plastic tower cover.  Actually a very convenient location.   My unit has a 4 wire lead that terminates in two terminals.  The terminals have a hole to mount on each coil terminal and a thumb screw terminal for the old wires that went to the same coail terminals.  Just a substitution.  Mine has a cut out/in switch that allows going back to points if the CD unit fails.   It hasn't failed since 74 when one of the transistors failed and was replaced.  Its nice not having to worry about spark plugs and points anymore and reving to 6K w/ no miss.  Its too bad they are so expensive now.  I only paid $75, but it has no bells like varialble dwell and timing like new ones. 

Good luck with picking / sopping for the unit.  I think I would call their support people and explain how simple your application is and see if you can get just a basic unit at entry pricing.

[fmen3366]

Thanks Gary, I might just mount it under the battery where the emission  electronic module is (my mechanic found out it was bad and just bypassed the unit). I'm a parts wholesaler and I'll check if they can at least give me some discount. I'll follow your advise and call tech support to see if I can get the basic module.

Andy