It just runs better with points!

[TheEngineer]

I did the cylinderhead, adjusted the linkage for the throttle & injection pump and adjusted the idle mixture until the car ran just fine. A few days ago, I installed the Pertronix II electronic ignition and found that the engine didn’t like it: At low idle RPM the spark actually disappears sometimes: I can see it with the timing light. The engine then just quits. At higher RPM it’s fine, but sometimes I got some backfiring at about half throttle. At full throttle it works great. Today, I installed points again: This is a 009 alu distributor and the shaft has about .006 in sideplay. It’s a pain to get the dwell just right: At first I had it at 36º, then as high as 45º. With a lot of fiddling, it’s now about 39º. It decreases when I increase RPM. The distributor has about 10º vacuum retard at idle and I set the timing at 1º after top dead center. It idles very nice at 600 RPM (and the tachometer agrees with the electronic tach.) And it runs wonderful. I would like to have electronic ignition because the points wear and it’s such a pain to get them just right. But it appears, I can’t have it. Bummer!

'69 280SL,Signal Red,007537,tired engineer, West-Seattle, WA

[hauser]

Go with the Crane!  It has worked for me without ever missing a beat.

1969 280sl 5 spd
Gainesville, Fl.

[n/a]

I have the Crane also and it is working just fine.

Louis 70 280sl Red Auto

[zanone]

I have new long block and IP and linkage adjusted on my car and I'm still getting backfire and stalling at low RPM with the Petronix installed. Runs fine at high RPM but cuts out and runs rough at low RPM. I'll let my mechanic know to try the points again. Thanks for the info. DZ

[A Dalton]

While both Hall Effect and Optical switching are a major improvement over mechanical switching , the optic light beam shuttering is certainly a better system than magnetic hall effect .
 Halls are susceptical to dist shaft runout/play , where the optics are not due to the shutter being lateral from the dist shaft axis.  
Halls also suffer in that their design has a flaw that low rpms
[ like cranking]  decrease their output [ requiring amplification] whereas optical systems switch as well at low rpm as high.
 The beef everyone has w/Crane system is more directed at the mounting hardware for the led/photo switch bracket needing a little custom fitting/filling  to fit the Bosch distributor.  But seldom do I see any performance complaints .
 I think that for many ,the big feature for choosing the Pet. is the unit fits in the dist and there is no S/G to hide .. but the Crane can be mounted under the bat tray..
 Optic are just a cleaner, faster, technically superior way of switching a signal than a Hall Effect magnetic sensor , simply by design.. light beam vs magnetic field...
But, either way, both better than mechanical switching , that's for sure...
...just some things to consider........
 

[hauser]

Go with the Crane!  Hide the unit under the battery tray and forget about it.

1969 280sl 5 spd
Gainesville, Fl.

[Bearcat]

Can anyone leave an address where to source a crane ignition kit also what is the type to buy or is it just for 6 cyl cars?

280SL 1970
S500  2000
E220Cdi Est 2005

[Naj ✝︎]

Bearcat,
 

quote: Can anyone leave an address where to source a crane ignition kit also what is the type to buy or is it just for 6 cyl cars?

I got mine here:

https://www.usautomotive.co.uk/Crane%20Cams/ignition.asp

I got the 700/0231 (works for both 046 and 051 distributors).
Also, I used the smaller of the 2 six slotted discs, which allowed me to keep intact the brass post for the contact points; in case I have to change back.

Download Attachment: Tim209.JPG
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I did try the pertronix before this and gave up  :oops: .

naj

[Bearcat]

Naj, thanks a mill. I will order it on Monday. I also wanted reassurance that the XR 700/0231 was the correct model...brill.

David