Project Potential... variable vane turbo on 1.6l

[DVST8R]

I wish CNC mill, just CNC plasma and an old lathe, but they seem to get the job done :wink:

[jackbombay]

Nice work, can't wait to read about how it runs!

[Audi80]

I made this a couple of weeks ago. Haven`t tried it yet though.

[QuickTD]

I am excited about trying this contraption out!

I'm excited to hear the results. This is exactly what I had in mind.

[malone]

Good lord, that's an impressive progress! Nice work.

[fspGTD]

Thanks for the compliments guys!


Audi80 - wow that is impressive work as well.  It looks like one of the larger VNT turbos?  Can you tell us more about what you did?  It looks like you used the stock VNT can as a starting point, but it looks like maybe you welded a flat piece to the half of the can that is away from the turbo.  Did you do that to make it flat and allow increased travel of the flipped over diaphgram inside?  Did you flip the diaphgram over inside?

[fspGTD]

I'm almost done fabricating a stainless steel EGR block off plate (which is very carefully crafted to allow clearance of the long-runner 1.6lNA intake manifold...   ) There is not enough clearance for the long-runner A2 gasser intake with this manifold so now you know why the TDI guys aren't slapping those on their motors (I don't know if an A1 gasser intake would fit or not...)  Also am almost done fabricating the turbo oil outlet flange (out of aluminum... waiting on some AN fittings to arrive in the mail which will either weld or screw into the flange.)  Also out of thick stainless am almost done fabricating a turbine outlet flange.  Man that stainless (300 series... nonmagnetic) is tough to work with.  It was really challenging making the big hole in the middle.  I went through quite a bunch of drill bits drilling a bunch of little holes to try and make one big hole (after toasting a hole saw.)

I tore off the passenger motor mount and the head also today.  Motor mount is shot - big surprise  :roll: .  What really did surprise me though was how loose the timing belt was set - and that the car ran like that for so many miles (it's been years...) without self-destructing.  The belt even looked to be in OK shape.  I've never seen one so loose and floppy!  It was so bad I could twist it 90 degrees!  Whoever tensioned it did it incorrectly, turning the tensioner the wrong way (causing less belt wrap around the cam.)  The tensioner bolt was on plenty tight so that wasn't the problem.  There is a lot of other evidence abound of sloppy previous mechanic work... I'm finding a bunch of fasteners that are either "he-man tight", or "almost ready to rattle off" loose.  I have been perplexed at this engine's smoking problem, hopefully that loose timing belt is the main culprit!  I never did double check the cam timing... I did set the injection timing though (set it off the crank TDC mark.)

Oh by the way also once I got the head off I looked at the pistons and found that they are the largest overbore (77.5mm)  Nice to have a little extra displacement.  

[DVST8R]

Tip for SS and SS not just 304-309-316 ect... Go SLOW and keep it COOL as soon as it heats up it goes redicoulsly hard, and eats drill bits, hole saws ect... If your welding it (I know you don't have a TIG setup) Stick is probably the next easiest for 300's SS, Then either oxy-fuel, or Wire.

Sounds like some good progress!

[fspGTD]

Man does that stuff get hard when it work hardens!  I did not realize the hardening was triggered by heat.  I just have a little bit of crud around the inside edge of the turbine flange left to grind off and then it will be done.  I am happy to have gotten that far.

I am thinking about going 2.5" stainless downpipe tubing, but with that size it looks like I would have to dent the tubing to be able to access two of the nuts.  The exducer bore of this turbo, after the machined-in step, is only 1 3/4"!  This is a small turbo, at least compared to stock 1.6lTD units.  :lol:

This stainless tubing I got is grade 409 I'm pretty sure.  I have not welded it before, but I can competently oxy-weld 304 (I made an entire exhaust system of my Rabbit that way.)  Any tips on welding the 400 series stainless?

[fspGTD]

Does anyone here know if aluminum AN nipples can be welded? (...to 6061 aluminum)

[veeman]

Does anyone here know if aluminum AN nipples can be welded? (...to 6061 aluminum)

I believe so.  A racer friend of mine attached AN fittings to an oil tank (Porsche) and to some oil cooler cores to make them AN compatible.  Obviously, the right equipment, settings and a bit of know-how are necessary...

[DVST8R]

400's, really aren't that much differnt as far as welding goes, I'm sure that you wont have a problem.

As far as the Al 6000's weld just fine as long as there not heat treated IE. T-6 it is still possible to weld those except that you loose the heat treatment in the process. If it is just normal 6061, no problem, but you will loose most of the cool anaditzaiton (sp?) coloring, but other then that it will be just fine. The Key to welding aluminum is to have it CLEAN! with chemicals and brushed. Also rember that the oxide that forms over Al. doesnt melt till like 3000ish degrees and Al melts at like 1800ish, so the puddle doesnt last long b4 it melts through! **As it starts to turn dull from shinny you can start to add filler even though it doesnt look like a puddle in most instance's** make a few practice welds on similar sized scrap first. Like anything it just takes a little practice. :wink:

Hope this helps some. You can weld Al with oxy-fuel jsut have to find some flux, (i heard that you can get flux filled tig rods for welding realy poor Al. those might work for you) Try BOC , or Air Liquide for other flux's, some body will have it.

[QuickTD]

Does anyone here know if aluminum AN nipples can be welded? (...to 6061 aluminum)

Quality aluminum fittings and hardware are often made from 2024 aluminum. It is quite hard and cuts very freely on high speed lathes without the gummyness inherent to softer alloys like 6061. 2024 (or 7075 or any other high strength alloy) is not very weldable, it tends to crack. Best to weld on threaded bungs and then screw the fittings into those or thread the adaptor plates themselves

 Another tip for stainless, use lots of pressure and use sharp tools. One revolution of "rubbing" with a dull drill will form an impenetrable skin... I find the CNC mill does an excellent job. It is absolutely merciless. It never gets tired and backs off like humans do...

[MrDave]

That's real pretty.  I'm impressed.  
Do you have it on the car yet?


-Dave

[fspGTD]

MrDave: Nope.  Still fitting and fabrication... this is a big job, I am doing a lot of stuff all at once to this car.  I am making great progress though.  I got the motor mount hacksawed out and a new one pressed in, and motor mount re-installed in the car along with the other injection pump mounting brackets.  And got the whole passenger side of the motor and brackets cleaned up (had a thick grease cake, leaking valve cover gasket.  :roll:)

On the turbo I had to remove the compressor housing and sand down the compressor inlet nipple, because it was some weird metric size, and was 1/32-1/16 or so too large for the 1 3/4" aeroduct I got to slip over.  Aeroduct doesn't conform by expanding in diameter by very much!  I also sanded and polished the turbo air inlet so it has a nice and smooth bellmouth type opening.  That is the smallest restriction point in the intake tract where there is only atmospheric pressure to get it though.

Others: I will probably not attempt this aluminum welding with my oxy-fuel rig myself... But that's great to know it is weldable.  I will probably take it somethere to have it done.  I do have some aluminum welding flux, but when I tried it previously I did not get good results.  I need more practice before I can weld aluminum, which I don't have time to do right now.  I can do stainless and mild steel great though.  My brother's in town now and I just last night helped him welding a blow off valve flange onto a boost tube for his mitsubishi eclipse.  He just got back from army training where he's a metal worker, and just got certified in welding.  But I was the one who ended up doing the welding!  I am more experienced with and know my oxy-fuel welding rig better.  They don't teach the use of antiquated welding tools in welder's school I guess.  :lol:  But I enjoy playing with molten metal whenever I get a chance.

Oh... I will be welding a (steel) AN nipple onto the oil pan with my oxy-fuel rig.  That should be fun.

I have another fabrication job for this project coming up... modifying the NA diesel intake manifold for forced induction.  Can anyone help me with a plenum volume calculation of the NA intake manifold and tell me if it's adequate, too much, or not enough?  I have not done that yet but I probably will need to before I can finish it.  I also have a couple decisions to make for manifold boost pressure adaptation - to bolt on an aluminum plate to the front with some sort of gasket, or to weld?  And other question is where to put the air inlet nipple - front, underneath, or one of the sides.  I think I will get the head back on and hang the manifolds on the car seeing where things sit to figure that out.  If I want to get this done quicker, I could bolt on the turbo manifold temporarily and save the long-runner NA manifold project for later.  That might make some sense...

I'll post another round of pics shortly.

Oh by the way Quick, Thanks for chiming in with your experienced tips of stainless working.  I am sure I was doing it very very wrong.    Actually the cobalt twist drills were the only thing I was able to get through that stainless with any reasonable speed.