[T3] Valve Settings/Distributor Drive Gear

[Chris Sheridan]

I've done some digging, I consulted the law firm of Muir, Wilson, Haynes,
Ball and Clymer trying to find the origins of the technique I mentioned. I
admit that I'm wrong this technique is not mentioned in Muir. I learned it
25 years ago from my mentor. I was 20 at that time and he was 30. It's been
awhile. I've always used it since then and always attributed it to Muir. I
emailed him the other day and asked him about it. He stated that it was a
technique he learned from his father, who was a shade tree VW mechanic in
his backyard in Connecticut in the 1960s working on old bugs. My mentor was
the son who held the flashlight for him. I could not go directly to his
father because he passed away a few days ago at the age of 90. My mentor
said he thinks his dad taught it to him and they worked primarily on 40 hp
bugs and some buses but not type 3's where there is the additional issue of
the vacuum can hitting the case.

I believe now that I adopted this technique because we had a motor where we
couldn't find Top Dead Center at all, and we had no faith in the origin of
the rebuild, the position of the distributor drive shaft, the provenance of
the distributor, etc. It provides an extra layer of insurance that you
aren't mixing up TDC #1 with TDC # 3.

The Technique:
1) Remove distributor cap
2) Remove both valve covers
3) Rotate the engine while holding a small mirror to watch the #3 tappets
4) After a couple of cycles you will see a point where the #3 Intake valve
tappet is closing just as the #3 exhaust tappet is opening.There is a
precise point where the tappet heads are aligned as they travel in
different directions. The point at which
you can hold a imaginary level across both tappet heads, the point where
the intake has barely closed and the exhaust has barely opened is where you
stop turning.
5) This method insures that you are at Top Dead Center for #1
6) After setting and checking the valves for #1 you can then turn the
engine counterclockwise about 90 degrees turn of the rotor but this time
using your mirror to find the sweet spot on the #4 tappets, to determine
tdc for #2, and so on.

I think this method was adopted for several reasons:
1) We were working in the street with minimal tools, and had never see a
distributor drive shaft puller and didn't know how to get one and were
afraid of moving that as the cars we were tuning were not ours
2) Oftentimes on these bugs and buses, an 009 distributor had been added,
with no vacuum can present to bang against the case.
3) Very often the orientation of the drive shaft would cause the
distributor to find TDC for #1 in the opposite place that the books
indicated, which can be very confusing for newcomers.

How accurate or reliable it is, is to be determined by you. I am open to
adopting new methods. I am especially happy that I got to do a bit of
anthropology on this.
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