'01 Audi A4 1.8T quattro TDI Conversion

Something arrived in a badly crushed box today:



Woohoo! Pistons!



I cannot understand why anyone would pay $850 from TDI-centric online stores for these pistons when they're readily available from RockAuto for $70 each. Including shipping from Europe, this piston set cost me $325 USD. Also includes rings, wrist pins and circlips. And these are 0.5mm oversize. Standard size is the same price.

Engine shop confirmed that the wear on the block was fairly uneven, and at the absolute limit for stock-size pistons, so I figured I'd just go oversize and have everything align-bored/honed while I'm at it. Hard to go wrong for $325.

Alright, I think I've got the front axle thing figured out.

My A4 has 100mm flanges at the 5 speed transmission and 38 spline hubs. European cars could have other combinations, but all US spec B5 A4 models were setup this way.

My TDI 6-speed transmission has 108mm flanges, which were found on B5 S4 cars. But those cars use a slightly different 38 spline hub.

So to make this work, my options are:

- swap my TDI transmission's 108mm flanges for 100mm flanges. This is easily done, I have a spare rear end with 100mm flanges that would bolt right on. Then I could just use standard A4 front axles. But it would mean using the weaker 100mm axle joint.

- swap the steering knuckles (aka "uprights") on my car for some S4 steering knuckles. They're easy to find and relatively cheap. This would allow me to run the stronger S4 axles with 108mm inboard joints. Also, bigger and stronger front wheel bearings.

Hmm... dilemma.

edit: I went with the S4 uprights option. I'm gonna have the front end apart to swap out the subframe anyways, so this is as good a chance to swap uprights as any. $120 for each upright, not bad.

Here's an interesting observation I've made over the last few weeks of this project. I've been ordering a TON of parts for this swap from countless resellers all over the globe. I've been working hard to find the best prices on good quality parts, which often means ordering from many different places. For example, rod bolts were cheaper from Jim Ellis VW, but rod bearings were cheaper from Parts.com. So far, they've all been shipped via either FedEx, UPS or USPS, typically from either California or the midwest. I live in the Northeast.

- all USPS packages have arrived on time and in perfect shape

- all UPS packages have arrived either on time or EARLY (!!!), and in perfect shape

- _ALL_ FedEx packages have arrived either late, damaged or didn't arrive at all

One large order in particular, a $1200+ package from Bora Parts, somehow got so trashed that FedEx didn't even bother trying to deliver it. They just sent it back to Bora Parts as soon as it arrived at my local FedEx depot. So it took a week to travel all the way across the continent, and now it'll be another week before they get it back.

My pistons from Europe... well, the picture can be seen above, but that picture doesn't do it justice. It's a miracle that box retained its contents. The driver was hesitant to deliver the package, he figured I'd just refuse it. Luckily RockAuto did a fantastic job of padding the individual piston boxes.

Good times.

Received something else from Europe today... a turbo! I went with a GTB1756VK instead of the GTB2260VKLR I was originally planning on. I got an "uprated" one from fellow forum member X-Man, with a billet compressor wheel and upgraded bearings and seals. Claims it's good to 270hp, which is way more than I ever hope to achieve. It was custom built and clocked to my specs. I couldn't be happier with the results:









If I blow with my lungs really hard, I can get the compressor wheel to spin. That's pretty damn impressive.

X-Man has been a pleasure to deal with, and I got exactly what I wanted despite totally changing my mind halfway through. I highly recommend him for anyone's turbo needs.

More parts arrived today! My injectors are back, now with brand new Bosio 783 race nozzles, calibration and installation kit from DBW LLC.



I really want to thank Peter at DBW for going above and beyond with these injectors. Turns out the person who removed them also damaged 2 of them. I know they were working fine before I pulled the engine. It looks like the 2 damaged ones got dropped. One had a cracked connector and was no longer firing, and the other just wasn't firing. Peter replaced the bad/cracked solenoid, and disassembled/cleaned/re-assembled the one that was mysteriously not working. Now all 4 injectors are working again. And the only extra cost is the new solenoid ($125). Fantastic service by DBW, and a quick turnaround too.

Got a bunch more goodies over the last couple days.

Rod bolts from Jim Ellis VW:


Rod bearings from parts.com:


Colt Cams stage 3 cam from KermaTDI:


Cam followers, tandem pump gasket, head gasket, PD150 head bolts, cam cap bolts, cam bearings, thermostat, glow plug elbows and main bearing bolts from Bora Parts:


Short throw shifter kit from JHM:


Front shocks and coil-over adapters from ECS Tuning:

(diesel swap-related because I'll be swapping the front springs to accommodate the heavier engine)

Rear swaybar kit from 034 Motorsport:

(not technically related to this diesel swap, but cool all the same )

A couple of observations about these vendors:

- Bora Parts has fantastic customer service. They really understand how a customer might be in a bind with time and will bend over backwards to get things done quickly. I'm extremely happy with them.

- KermaTDI has amazing email customer service, even for casual questions. I ended up not really needing most of the parts they sell, but I bought the cam from them anyways (instead of a forum vendor) because I figured they deserved a sale after spending time answering all my questions.

- Jim Ellis VW and Parts.com have a great selection of VAG parts at prices that put my local dealers to shame. I found Jim Ellis VW's shipping cost to be a bit on the high side, but it was still worthwhile considering the product prices. Parts from both vendors got here quick. I've placed a second order with Jim Ellis VW.

So I'm still waiting on a huge box of stuff from Bora Parts (wrecked in shipping by FedEx), Jim Ellis, IDParts and Darkside Developments. It's like Christmas every day! Except I'm paying for my own presents, and I'm spending more on myself than I should be...

Crap, can't find new bushings to rebuild the rods. They seem to be non-existent. Guess I'll splurge on a set of IE rods instead. Here I thought I'd saved $700, turns out not so much And I wasted money on new rod bolts too.

I don't even want to know how much you've spent lol All the small things add up so fast

tophergrace said:

I don't even want to know how much you've spent lol All the small things add up so fast

Click to expand...

True story bro!

Oh man, I've got a tally sheet here, and I probably won't share it at the end. It's too embarrassing. But I don't care, it's also a ton of fun.

Yay, more goodies today!

A bunch of gaskets and O-rings from Jim Ellis VW:


High lift valve springs and a front mount intercooler kit from Darkside Developments:


The stuff from Darkside got delayed a bit due to a lack of silicone tubing, but once they got it shipped out, it got across the ocean and to my front door in 2 days (!!!) Unheard of! Oh, and undamaged too, thanks to excellent packaging and DHL's careful handling.

GoremanX said:

Oh man, I've got a tally sheet here, and I probably won't share it at the end. It's too embarrassing. But I don't care, it's also a ton of fun.

Click to expand...

A wise man once said save all your receipts.......Never add them up

Oops, forgot to take a picture of my new IE Tuscan rods before bringing them to the machine shop. Oh well. I'll try to remember to take a picture before I do the final assembly.

Instead, here's a more interesting picture that gave me a woody:



Machinist got done working on the head. That's a shot of the gasket matching he did on the exhaust ports. The ports are way smaller than the exhaust manifold runners, so I figured a little porting work would help provide a smoother transition to spool up the turbo faster. The result is exactly what I wanted, a smooth radius that goes about an inch down the throat. I can't feel a single edge inside, there's no obvious transitions. The opening is slightly smaller than the gasket to account for squish when everything is tightened down. The gasket already matched the exhaust manifold runners perfectly.

He also did a 3-angle valve job, lapped all the valves and milled the deck to make up for the new valve depth. There's no need to gasket match the intake ports because they're already identical to the intake manifold runners. I'll just do some trimming of the gasket to remove the edges that stick out into the port opening.

Looks like all the machining to the rest of the engine will be done next week. They're going to check clearances on all bearings and then I get to bring the whole thing home in pieces to assemble myself.

Woohoo!

GoremanX said:

Oops, forgot to take a picture of my new IE Tuscan rods before bringing them to the machine shop. Oh well. I'll try to remember to take a picture before I do the final assembly.

Instead, here's a more interesting picture that gave me a woody:

Machinist got done working on the head. That's a shot of the gasket matching he did on the exhaust ports. The ports are way smaller than the exhaust manifold runners, so I figured a little porting work would help provide a smoother transition to spool up the turbo faster. The result is exactly what I wanted, a smooth radius that goes about an inch down the throat. I can't feel a single edge inside, there's no obvious transitions. The opening is slightly smaller than the gasket to account for squish when everything is tightened down. The gasket already matched the exhaust manifold runners perfectly.

He also did a 3-angle valve job, lapped all the valves and milled the deck to make up for the new valve depth. There's no need to gasket match the intake ports because they're already identical to the intake manifold runners. I'll just do some trimming of the gasket to remove the edges that stick out into the port opening.

Looks like all the machining to the rest of the engine will be done next week. They're going to check clearances on all bearings and then I get to bring the whole thing home in pieces to assemble myself.

Woohoo!

Click to expand...

Awesome man you can't beat good headwork. Wonder why the gasket is upside down though. Keep up the pics and the good work this thing should throw down some serious tq.

tophergrace said:

Awesome man you can't beat good headwork. Wonder why the gasket is upside down though. Keep up the pics and the good work this thing should throw down some serious tq.

Click to expand...

Good call! Because I put it on upside down to take the photo Doesn't matter though, the port holes are the same shape and location in either direction, and the machinist did the work with the gasket on the right way.

Some minor updates on this project.

There's been a slight delay with machining the engine block. With the new pistons and rods, the piston protrusion from the deck is no longer sufficient for even a 1-hole head gasket. It's also not as even as I'd like between each cylinder (varies from 0.813mm to 0.863mm). So the block deck needs to be align-milled. Still looks like I might have everything back here by the end of the week.

Bora Parts got the damaged package back from FedEx. One of the bottles of break-in motor oil was pierced and leaked its contents all over everything in the package, hence the decision by FedEx to send it back to the shipper. After swapping out stuff that got damaged by motor oil, Bora Parts has sent the package to me again and I expect it here by Saturday.

I bought brand new valve guides for the head, but it turns out I don't need them. The machine shop pressed brass liners into the existing guides before doing the valve job to make up for the wear. These inserts are machined with very precise clearances to accommodate the OEM valves that I'm re-using, so they're even better than using new valve guides. Yay me!

Just received the long lost package from Bora Parts. Includes a BSM delete kit with BRM oil pump gears, a timing belt kit, break-in oil kit and a slew of other minor stuff (filters, gaskets, seals, etc). I'm pretty much ready to put this engine back together. The last thing holding me up is the valve spring installed height measurement, which is proving difficult to acquire accurately. I'm not sure what method I should be using to measure the installed height on a PD TDI, and the numbers I'm getting with a ruler appear to be way too short (25.4mm vs 26.6mm). I don't even know how much valve spring seat is safe to cut.

Once I have that figured out, I should be good to take all the parts home and re-assemble the puzzle!

Things have slowed down a bit. I got the engine parts back from the machine shop. Finally figured out the valve spring installed height thing (I was measuring wrong). Turns out my installed height is perfect and no adjustment is needed. As soon as I brought the engine parts home, I sent some of them right back out to get coated.

Piston tops are getting a gold thermal reflective ceramic coating.

Combustion chambers (head and valve surfaces), valve radii and exhaust ports are getting a regular thermal reflective ceramic coat.

Exhaust manifold is getting a white thermal reflective ceramic coat.

Valve stems and valve springs are getting a peko poly moly coating.

Piston skirts are getting a lubrication coating.

Unfortunately, all this is taking 2+ weeks In the meantime, there's not much I can do.

I did install the main bearings, crank and caps, and I drilled and tapped the BSM oil feed hole in the block:



I went with a hex-head brass plug rather than a flush allen-head one. The protruding hex head fits perfectly in one of the holes of the windage tray, and will help locate it more positively. I'm really not sure why everyone else uses the flush-mount allen-head plug. Guess I'll find out the hard way if there's a downside! I did use JB Weld to secure it in place.

Anyways, now I'm playing the waiting game...

I need some advice with the fuel system. Turns out the Passat and the A4 have nothing in common where it comes to the fuel tank. FWD and quattro/4motion B5 cars use completely different fuel tank designs that are not interchangeable, and the pump housing doesn't even come close to matching.

Is it possible to modify my A4's existing fuel tank to accommodate the new diesel powertrain? I see unnecessary vapor recovery lines and an incorrectly sized nozzle opening. How do I deal with those things? Is there anything else I need to worry about?

Also, I probably need to change the high pressure fuel pump for a low pressure lift pump. A part number for that would be useful.

You're over thinking this one. Keep the stock fuel tank and just swap in a low pressure fuel pump from a passat tdi. It's not s direct swap as you have to get the passat lift pump it'self free from the housing and swap it into the a4 housing.

It's not to bad some soldering may be required

Regarding the fuel pump/sender: you may have a sender problem if you just swap the whole TDI pump/sender unit from a VW model (assuming you plumb in the fuel line to the other partition in the quattro tank).

I found that the sender ohm signal from a jetta tdi was inverted as to what the Audi cluster was expecting [physically full was reading empty on the gauge]. Then there is the whole problem of the jet pump in the driver side of the quattro fuel tank which has its own sender unit that goes in series with the passenger side and then onto the gauge in the cluster...

Well I have no choice but to re-use the OEM pump housing. Nothing else will fit. That means I'll be re-using the Audi level sender. I'll check to see how well the Passat's lift pump fits inside the the Audi housing. It looks like a simple soldering job with the wiring.

My main concern is with the nozzle opening size. Most diesel pumps around here have a large nozzle that won't fit in a gasoline tank opening. And it doesn't look like that opening is interchangeable.

GoremanX said:

My main concern is with the nozzle opening size. Most diesel pumps around here have a large nozzle that won't fit in a gasoline tank opening. And it doesn't look like that opening is interchangeable.

Click to expand...

I just used tin snips and cut the flap in the filler neck and the flap housing out. I did drop a few pieces into the tank and had to fish that out via the tank side, but it isnt that bad when everything is all apart.

For reference, the TDI quattro fuel pump part numbers are as follows:
1J0919050A ASZ quattro in tank fuel pump unit 2002 A3 tdi pd;
1J0919673Q ASZ quattro driver side sender unit 2002 A3 tdi pd.

Thanks! I hadn't even considered that. I think this solves my current issues.

ta79pr said:

I just used tin snips and cut the flap in the filler neck and the flap housing out. I did drop a few pieces into the tank and had to fish that out via the tank side, but it isnt that bad when everything is all apart.

Click to expand...

^^^^this^^^^
This is what I had to do, and i used a chisel and file to open it up even more to fit the truckstop nozzle. I had to suck all the debris out of the tank with vacuum though the fuel pump access hole.

Lots of progress recently. I received the coated internal engine parts earlier than expected, so I've been re-assembling the block whenever I get some free time. Things are going well. Unfortunately the head gasket got damaged in shipping with the engine parts (Swaintech uses the head gasket to determine masking on the combustion chambers), so now I'm waiting on a new head gasket from ID Parts.

Here are some photos!

The coated engine parts


Exhaust valve on the left, intake valve on the right

I only had the radius of exhaust valves ceramic coated. Ended up having to re-lap the seats as a result.

Pistons and springs

The gold coat looks stunning. The PC-9 coating on the skirts is surprisingly tough, much better than the tiny patch of poly moly that Nural puts on the pistons from the factory. I'm really happy with the way the pistons turned out.

Combustion chambers coated too


This includes the valve faces


Also had the exhaust ports done

Not sure that I would bother with coating anything on the head next time. Especially the exhaust valve radius and the exhaust ports. Having to re-lap the valves is tedious, and it showed just how delicate this coating really is. They don't use the same material on the head that they do on the piston top. The white stuff can come off fairly easily with mild scrubbing and a solvent.

Here I've assembled the rods to the crank. Everything is torqued down.


ALH oil pump with BRM chain cog, ALH windage tray



Note the spring I added. I saw that many other people do this, and I happened to have a perfect spring for it, so I did it too. The spring comes from my JH Motorsport short throw shifter kit. It included 2 extra springs for the reverse push-down (to fine-tune the spring resistance), and those springs happened to be the perfect size for a press fit in the square cavity of the windage tray. The spring is a VERY tight fit, I had to work hard to get it in there. But it sits flush, and it's not going anywhere. I used the stiffest spring of the kit.

Oil pan, front cover, crank cog pulley and new bolt installed and fully torqued


I don't have a photo yet, but the valves, valve seals and springs are installed in the head. I've also made some progress with my transmission. Turns out I needed a whole lot more parts than I thought to get the shifter hooked up.

Anyways, that's my progress so far. Looking forward to getting the new head gasket so I can to work on more of the valvetrain! I prefer to have the head bolted to the block before I do cam and injector stuff.

oops, never did show off a picture of my new IE Tuscan rods, so here's one of them in all its mobile phone glory

Here we go, a valved and sprung head, awaiting its new head gasket.

Looking Good!

Those engine parts look great. You should have a very strong capable engine once finished. I'm curious to see the performance of your turbo, might be a good all around turbo. I have the gtb2260 on my Passat, but it surges pretty decently below 2500 rpms when I get on it too hard.