Date:         Wed, 15 Nov 95 13:38:30 +0100
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         verbeek@the-hague.stbv.slb.com (brian verbeek)
Subject:      Re: #3 late timing + Minutiae: Timing

On Mon, 13 Nov 95 17:57 CST Jim Bryant said:

>>in 1965 Volkswagen gave a special grind to the cam in the distributor
>>to cause #3 to fire 2-1/2 degrees late. This was done to aid cooling
>>of #3 cylinder which is farthest away from the fan.

And:

>>I *do* have to wonder why it took so long for VW to incorporate
>>this idea in their engines.


I see some reasons for this:

-The bigger 13/1500s were pretty new in '65,
the earlier, less HP engines probably had less coolingproblems.

-VW changed the cooling and heating systems in the early 60s.

-AND, timing one cylinder different than other cylinders in the same
engine is not desirable.

VW obviously first had to recognize the problem and started research,
changing ignition timing in this manner is probably the last thing to
do. (and the cheapest/fastest/easiest)

Alex Munro said:

>>it sure seems easier and cheaper (and completely retrofitable to older
>>models) just to move the location of the Spark plug contact in the
>>distributor cap.

I disagree on this, the location of the contact in the distributorcap is
determined by the location of the rotortip on the moment of ignition (Spark).
When there is a spark to come off the rotor it has to be able to jump
over to the contact that has the correct plugwire connected to it.
This means that if you move the contact, you only enlarge the gap that the
spark has to jump.

If only want to change the timing of one cylinder you *have* to change the
distributorcam, there is no other way.

Brian.
'73 singlecab