Bosch 009 lobe removal for 1/2 VW

[Bob Wood]

On Leonard's build video for his motor he explains how he identifies lobe 1and 3 to grind off. He explains that lobe 3 is retarded by design and it needs to be taken off with number 1 to leave 2&4 to fire the engine. 

What happens if you grind off lobes 2&3 by mistake before you saw Leonard's video....what would the effect be on the running motor? My motor has been running in this condition, and seems ok but could be smoother....if I have to replace the distributor can I buy a shaft to replace mine.
Is Great Plains a good place to get the non copy 009 distributor.

Thanks for the help
Bob

[Dan_]

....what would the effect be on the running motor?
Thanks for the help
Bob

The retarded cylinder would be producing less power, and perhaps the engine would not seem as smooth.

There is hope you do not have a retarded #3 distributor.  After 71 they changed the oil cooler and discontinued the practice.

Scroll down to "oil cooler" on this web page for the 411 on it and how to figure out if you have #3 retarded or not.  Below is a cut and paste from the web site...

4mm is 5/32 inches --an easily observable offset in a cam lobe, but one could use the trusty old test light timing rig I suppose. 

(edit:)  Be sure the coil wire is removed if you power up the ignition and move the prop...
(edit:)  the 4-5 mm is the offset in the timing mark... the cam lobe offset will be half that.

Oil Cooler

A problem occurs in mismatching the 009 distributor with the doghouse-type oil coolers. Up to and including 1970, the oil cooler was internal to the fan shroud, and this meant that the #3 cylinder (left front) got warm air for it's cooling and therefore ran hotter than the others. So VW altered the timing on the #3 cylinder only -- the cam in the vacuum distributors has #3 cut 2-3 degrees later than the other three cylinders, to reduce the heat load on that cylinder a little. The early 009 distributors also had this feature.
But since 1971 the engines have a doghouse oil cooler that sticks out the front of the fan shroud. After passing through this oil cooler, the hot air is dumped overboard through some extra tinware. The fan itself is a little larger to supply this extra air. You should be able to see/feel this cooler sticking out the front of the fan shroud (front is front of car), slightly left of center. When you're under the car you should be able to see the rectangular air outlet in the tinware just above the bell housing. If the shroud is smooth/straight right across the front of the shroud, you have the earlier type of "in shroud" cooler.
So with the newer type oil cooler, the #3 cylinder now gets nice cool air for cooling, and the retard on #3 is not needed. The double vacuum distributors therefore have no retard on the #3 cylinder (double vacuum distributors were only used on '71 and later engines). VW dropped the retard on 009 distributors about 10 years ago too. So some 009 distributors have the retard, some don't. You need to make sure you have the right one. The only way to tell is to time the engine on #1 as it should be, then look at the timing for #3 (turn the engine 360 degrees). If the points open at the same time, okay; but if the points are opening later (the timing mark is now more about 4-5mm to the right), it's the wrong 009 distributor for a doghouse cooler engine.
You see where messing with VW's design leads -- YOU become the engineer! This is okay so long as you know what you are doing, but most folks operate in a "partial information" arena, and don't realize that alterations to one component may not be compatible with another.
Returning to the doghouse oil cooler -- the fan on cars equipped with the doghouse cooler is fatter for greater airflow, because the cooling air through the cooler is vented overboard BEFORE the cylinders get the air. But if you have a close look at the doghouse shroud internally, it has two distinct separate passages leading from fan to the oil cooler (one from each side of the fan). So the bigger fan is designed to maintain the shroud air pressure in the rest of the shroud while allowing a separate additional flow to the cooler.

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