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914World.com _ 914World Garage _ New Timing Light Time
Posted by: yeahmag Oct 27 2017, 08:03 PM
No good deed goes unpunished...
At some point I lent my trusty, old timing light (dial back style) to someone. No idea who and no one so far has offered to return it. So, I need a new one. Couple of problems though.
* Most new(er) dial back and (all) digital lights reportedly don't work with a multi-spark CDI ignition system.
* Assuming I need to now buy a "simple" (non-advance) light. How the hell do I know what my timing is set at?
Certainly I can hit the 27 BTDC mark and goof around from there, but I'd really like to know EXACTLY what my timing is set at!
What do others with an MSD or Mallory use? If using a "simple" light, how do you hit, say 28-30 BTDC?
-Aaron
Posted by: Dave_Darling Oct 27 2017, 08:25 PM
If you're using a non-dial timing light, the best way to tell what the timing is would be to use a timing scale. Much easier in a Bug, though, as the crank pulley is easily visible from the engine lid opening. Note that some of the Type IV Buses had timing scales bolted onto the fan shroud. Doesn't help that much in a 914, though.
You can paint the edges of the fan so you can see different marks through the timing hole. You get a somewhat limited resolution that way, but you can estimate how far between marks you currently are and get some appreciation of your current timing that way...
--DD
Posted by: Mueller Oct 27 2017, 08:37 PM
As posted on your FB post, check out Pelican for their tech article with template for those numbers.
No idea on the CDI or how to bypass or trick it.
http://www.pelicanparts.com/techarticles/914_timing/914_timing.pdf
Posted by: Montreal914 Oct 27 2017, 09:20 PM
Used one... 
https://losangeles.craigslist.org/sgv/tls/d/engine-analyzer-from-the-70s/6355208084.html
Posted by: yeahmag Oct 27 2017, 09:23 PM
Math rules... I was able to use the Pelican Parts template (data) and the following website to calculate the distances for 28 BTDC and 32 BTDC
28 = 2.1259"
30 = 2.2778"
I used the distance provided for the arc (2.05") and the degrees of the arc (27) to find the radius (4.3502"). From there, you can calculate and arc length based on any degree you want!
http://1728.org/radians.htm
Now to make a template and make some marks on the fan.
Posted by: yeahmag Oct 27 2017, 09:29 PM
That's the light I had!
-Aaron
Used one...
https://losangeles.craigslist.org/sgv/tls/d/engine-analyzer-from-the-70s/6355208084.html
Posted by: Montreal914 Oct 27 2017, 09:37 PM
That's the light I had!
-Aaron
Used one...
https://losangeles.craigslist.org/sgv/tls/d/engine-analyzer-from-the-70s/6355208084.html
Might be yours...
Posted by: yeahmag Oct 27 2017, 09:55 PM
Here's 28 BTDC and 30 BTDC 
914_timing.pdf ( 21k )
Number of downloads: 56
Posted by: michael7810 Oct 28 2017, 07:20 AM
Does anyone know where to get a replacement clamp-style pickup for an old timing light? Mine disintegrated from age and I can get it to work with rubber bands and tape but it's a royal PITA. I have MSD and was going to buy a new light but after reading this I need to keep my old one going. Thanks
Posted by: bandjoey Oct 28 2017, 12:49 PM
My 2cents. Since I only use it every couple years. The HF light with dial adjustable works for me.
Posted by: johnhora Oct 28 2017, 01:50 PM
Posted by: mb911 Oct 28 2017, 02:47 PM
That's the light I had!
-Aaron
Used one...
https://losangeles.craigslist.org/sgv/tls/d/engine-analyzer-from-the-70s/6355208084.html
I have one of those lights. They are great..
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