[Fwd: A new Adventure on the way to the Audi 2.0 Turbo - or pullinggears]

[T Berk <tberk@mindspring.com>]

Here is another installment from our friendly Vanagon driver, Frank:

(btw- he is not on the list.)


Frank Grunthaner wrote:
> 
> I have had a new adventure (on the scale of my varied stimulations) and found
> an intriguing solution to a very difficult PIA problem, as I work my way
> through the hardware manipulations required to complete the Audi 2.0 Turbo
> project.
> 
> The problem: I'm switching to an all Saab/Bosch engine management system for
> engine and turbo control. This means LH-Jetronic ECU and fuel injection and
> the Saab APC knock-based control of turbocharger boost pressure and Saab
> ignition. As part of the Saab approach to detonation control, they use a
> distributor with Vacuum advance and retard, and no centrifugal advance. The
> Audi 3A engines (despite the erroneous notation on the EKTA) use a
> non-advancing distributor (knock sensor controlled ignition as per the CIS-E,
> Digifant and Motronic engines). I therefore wanted to make a Vacuum
> advance/retard only distributor compatible with the 3A engine. This Audi
> distributor uses a very large engaging gear (about 1/3 larger diameter than
> the regular VW counterpart) and a larger entry port for inserting the
> distributor into the engine. The VW CIS distributors have the necessary Hall
> ignition, but include both centrifugal and vacuum advance and a too small
> gear. The obvious solution, swap gears between the Audi and VW distributors!
> The manuals say: "Drift out (whack with a hammer and punch) the locking
> cross-pin and remove the gear from the shaft" Well it wouldn't come off!
> 
> I whacked and I whacked. I went through (means badly mangled) four Craftsman
> pin and center punches (love that guarantee - had to get the wife to exchange
> the second set) and still my sweaty reflection could be seen in the unmoving
> surface of the drift pin. After several shaking defeats (evidenced by the
> painfully swelling discolorations of too many of my smaller appendages) I
> took stock of the situation and went off in search of a machinist with the
> proper tools, level of experience and fully functioning digital subsets.
> Well, four of Pasadena's finest looked at them and said "those are like VW
> parts" and sent me on my way. One confident wizened fellow announced he
> couldn't get to it then, but they would be ready by noon the next day. Later
> I noted that his pinkie was absent on the right hand. Well, the next day soon
> became 7 days later with 5 successive one day excuses. On the seventh day, he
> announced (for the PC conscious please note I'm only reporting here) "Those
> pins are a real bitch. I've heated and cooled the shaft ... etc". You know,
> excuses. Then he said, "So I've sent them to a VW machinist (!!!) and they
> will be back tomorrow!" On the day after the morrow, he said "He just sent
> them on to a VW machinist (!!!) who specializes in distributors, they will be
> back tomorrow!" Then the exciting breaking story, "He has one of them out!,
> they will be ready tomorrow!"
> 
> Well to truncate this report, yesterday, he asked me to come and get these
> G...DD...M things the H..  out of here (trying to keep this clean). I picked
> them up, and clearly progress had been made ... the surface of the end of one
> of the pins was marred.
> 
> I then called Tectonics who had said, "just pound 'em out!" who now said,
> "Well I'd drill them out. Start at 1/8 inch bit then slowly work your way up
> to 5/32 then punch 'em out". He went on to observe that the pins were tool
> steel, and I should get a handful of high quality bits and prepare for a
> weekend worth of drilling.
> 
> I recounted my tale of woe to one of my trusty JPL machinists (with some
> minor embellishment) in a blatant attempt to solicit his professional
> assistance. Whereupon he said, "I'd plasma arc the damn thing!"
> 
> The solution: Well he sent me off to a little shop in an industrial
> park/getto in Irwindale. I showed the fellow my pieces. He asked a set of
> surprisingly well informed questions about the metallurgy and engineering of
> the gear and shaft system (and how much money and time I had), and announced
> he would give it a try, but for a litany of reasons there were no guarantees.
> Today at noon he called and announced that they were out and that would be
> $20 per pin please!
> 
> The wonder: What he did! He used a hollow electrode setup to strike a highly
> confined Nitrogen arc to rapidly cut the metal away (similar to a plasma
> torch). He calls it a metal disintegrator beam (!). He used a square
> cross-section electrode to cut through the 4 mm pin along its 15 mm length.
> Then pushed the remaining pin casing through! This thing cuts through
> hardened tool steel like butter, but there are no burrs or even
> discolorations on the inside of the gear or shaft hole. Amazing! Wow!
> 
> Oh, well as you can sense, I had a good time!.
> 
> His Name is Jim, his business is:
> 
> Bradley's Broken Tool Removal Service
> 5277 N. Vincent, #40
> Irwindale, CA 91706
> (626) 969-9565
> 
> Sorry for the length, hopes this helps someone else as much as it did me,
> 
> Frank Grunthaner

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