21 January 2011

Makin' stuff for the Jetta on the lathe

Even though Jettas came from the factory as either gas or diesel, some of the diesel-specific parts are NLA (No Longer Available) from the dealership or simply missing from the local junkyard. So when you don't have the parts you need, you make them!

When my engine came from the junkyard, it had a crushed the oil pan. Unfortunately, the turbo-diesel uses a special oil pan with an oil drain for the turbocharger -- a special oil pan that is now unobtanium. So I took a regular oil pan, drilled a big ol' hole in it, and made a threaded bung on my lathe. "Made" might be too strong a word, as I bought a brass fitting at Home Depot, chucked it in my lathe, and modified it. I can cut threads on my lathe, but that is an "advanced" operation that I don't have the time or tooling to tackle right now so it was faster to just buy something with the threads I wanted and cut away the stuff I didn't want.

Brass if fun to machine, by the way. It hisses and sprays a lovely golden glitter everywhere. It's like a Barbie glitter gun for men. Makes me want to make more flashlights out of brass than aluminum... but not until the Jetta is done!

Anyway, I attempted to solder my bung to the oil pan and completely and utterly failed. Solder stuck to my brass fitting but not the steel oil pan. Conceding defeat, Lemontree took it to her father, a career welder, and he brazed it (you can't weld dissimilar metals -- brass and steel -- so brazing, which is almost as good, is required). It may not be pretty but it'll be hidden inside the engine where no one will see it (arrowed in green).

Next up was a blockoff plate where the blowoff valve used to be. You'd think VW knew what they were doing when they engineered a car, but believe it or not, they stuck some extra stuff on there that is not needed. One of these things is a blowoff valve which is designed to prevent the turbo from over-boosting the engine... it's unnecessary because the turbo already has a wastegate to limit boost. And anyway, I sort of lost the little clamp that clamps the blowoff valve (oopsie) and of course the clamp is now unobtanium too (anyone that has one, needs it for their car!). Solution? Turn a blockoff plate on the lathe! Took a long time to saw off some 2" aluminum stock... I could really use a bandsaw, but just don't have a place to put it. :(

Plate made (arrowed in red above), I again (foolishly) tried to solder it on. Even more dismal failure. It seems I am not destined to work with hot metal, just cut it. Fine. This part is not subject to stress and only needs to hold back 15PSI of boost pressure, so, JB Weld that sucker on. Gotta get 'er done!!

Next I needed to mount the alternator. I'd lost the arm (yeah, I've lost a lot of things) that braces the top so I got some 1" x 1/8" flat stock from a metal supplier in town (well, Lemontree did... thanks Lemontree!), measured, drilled two holes in the drill press, cut to length, and ground down the sharp edges and corners (arrowed in red above). The thing is though, the alternator bolt hole is scooted over half an inch from where the arm is attached, so the arm either needed to be bent or I needed a spacer. Hm, making a spacer would require using the lathe, so... no brainer! Faced some 3/4" aluminum stock, drilled, and parted off to length (green arrow above). Since I haven't equipped my lathe with precision readouts yet, I eyeballed it and ended up .004" too short... ah well, close enough!

Next, I was somehow missing the correct lower alternator bolt. I had one that was too long but didn't have enough threads, so I just whipped out a die and cut some more threads, then cut the bolt shorter to a more convenient length. My hands now smell of the lovely sulfur-based cutting oil I used, mmmm, reminds me of Yellowstone.

Tomorrow the engine should go in. I hope.

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