T-Line Engine Build/Repair

[linet90]

Here's to another exciting journey...

My issue arose last summer in search of a boost leak which turned out to be a bad wastegate. I was also in process of installing a catch-can and Forge Diverter valve. Hoping to hold off replacing the turbo I continued with my install until a bolt went missing from the stock PCV valve. I was hoping that it didn't fall through the valve cover so I checked. The bolt was no where to be found but I did find something even more concerning. Check out this metal.



I, nor any other person that I have shown this picture to have any idea what it could be.
Finally got to disassembling the engine today. But there is no visible damage in the head cavity or valve train. Although, I did get the metal out of the motor.



These are fairly large pieces. Does anyone have any thoughts as to where they could have come from?
I am considering taking the head off if need-be.

After this metal issue is resolved I'll be replacing the turbo to something larger and am considering a IE intake manifold.

[linet90]

It has been a long time since I have gotten back to this thread but I have made progress!

This all started with those metal shavings, which I never found the culprit to, but has driven me to rebuild my motor. Today, my motor is in a million pieces scattered all over the downstairs of my house and garage. Many of my performance parts are already delivered and await some warmer weather. Here is a list of everything I got going in:

- JHM K04-R Turbo
- IE Intake Manifold
- IE Valve Train
- IE Piston and Rods (38mm)
- Eurocode Stage 3 Clutch

Those are the big ticket items as there will always me little odds and ends to this build. Once the warmer weather gets here I can strip the paint off the block and send it to the machine shop. My goal is to get this car back up and running by the end of the summer.

For some show and tell here are pictures of my car's life.




Empty Block



Found this treasure in a oil channel courtesy of my Audi dealer. This is from the cam bridge recall job. Finding this gave me an even bigger push to do the job myself.



Carbon buildup on the piston heads.



My cylinder 2 looks like it was running rich.



Please feel free to ask questions as I know I am missing details that I am sure will be valuable to others.
I'll keep updating as things move along on this build.

[LTopher]

That's quite the project you have going there. Looks great! Looking forward to future updates. Any idea what kind of power you'll have when finished?

I'd love to do something like that if I had more money/time/knowledge.

[linet90]

That's quite the project you have going there. Looks great! Looking forward to future updates. Any idea what kind of power you'll have when finished?

I'd love to do something like that if I had more money/time/knowledge.

Power is hard to tell, in addition to my new compression factor. My goal is to hit 350HP or better (at the motor).

I always dreamed of doing a build like this but never thought I could due to those same circumstances. After making some life adjustments I took on the challenge.
Knowledge is crucial and I cant keep track of how many countless hours I have spent researching the mechanics of everything. The home-run for me was getting the factory manuals and parts lists.
Here is where I purchased mine: https://www.emanualonline.com/

[linet90]

Here's some cool and interesting stuff.

The carbon buildup on the piston head is normal and probably mild in my case. What I found interesting was the wear on the piston skirt. It's normal in the majority of applications but ideally you would have none.



Some of this is due to the distortion in the cylinder once the cylinder head is installed. The difference can be up to .001" in circularity. To mitigate this I will be using a torque plate during the machining process.

As I was trying to disassemble the rods, and I say trying because I stripped a couple of the bolt heads, I was not able to find the parting line. Once I got one of the rods off the casting cracked and I thoughts I broke them. In actuality this is called a fractured-split. Lower cost to manufacture and always provides a perfect match.

[Spawne32]

lol first time rebuilding? that's actually not alot of skirt wear for a turbo engine. they are usually built to looser tolerances and have more skirt wear on the thrust side. fractured split rods are more reliable in most cases and significantly cheaper. i've always been curious to know what materials they use in both the rods and pistons given that they are factory turbo.

[Jason401]

You would think the fractured split lines would cause more stress and or fractures else where.

Hey I'm in RI also, following this build. Fairly new to Audi, made the switch from Vw with a B8 Avant.

LMK if you cant sourse a torque plate, I run a machine shop and can help with that.

If you need a hand wrenching or w/e LMK, I would def be interested in seeing this build.

[linet90]

lol first time rebuilding? that's actually not alot of skirt wear for a turbo engine. they are usually built to looser tolerances and have more skirt wear on the thrust side. fractured split rods are more reliable in most cases and significantly cheaper. i've always been curious to know what materials they use in both the rods and pistons given that they are factory turbo.

It is. I should also add that this motor only has 60k miles on it. From my understanding there is a correlation between boost pressure and gap. I haven't determined what my spec will be but for turbo longevity I don't plan to go over 20psi.

As for the rod material - I'm sure every manufacture has there own proprietary blend. High carbon steel per ASTM A29 seems to be most widely available and used in power trains.

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[Spawne32]

It is. I should also add that this motor only has 60k miles on it. From my understanding there is a correlation between boost pressure and gap. I haven't determined what my spec will be but for turbo longevity I don't plan to go over 20psi.

As for the rod material - I'm sure every manufacture has there own proprietary blend. High carbon steel per ASTM A29 seems to be most widely available and used in power trains.

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Not so much boost pressure as it is cylinder pressure/horsepower. Alot of aftermarket pistons now are using 4032 high silicon alloy's which are low thermal expansion compared to what used to be used, which was 2618. The piston to wall clearance when cold is alot looser compared to what you can run with 4032. As the cylinder heats up, the piston expands, which closes the gap on the rings, these are things you must account for with custom engine building. Along with bearing tolerances etc. Build it to factory spec and youll be fine.

[linet90]

You would think the fractured split lines would cause more stress and or fractures else where.

Hey I'm in RI also, following this build. Fairly new to Audi, made the switch from Vw with a B8 Avant.

LMK if you cant sourse a torque plate, I run a machine shop and can help with that.

If you need a hand wrenching or w/e LMK, I would def be interested in seeing this build.

Avoiding multiple fractures is the difficulty in the design/material processing. The key aspect is to have a brittle fracture opposed to ductile. In addition to strategically appling the stress load to fracture the rod.

Good to hear another member is in this small state. I appreciate the helping hand, I will PM you to discuss further.

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[linet90]

Not so much boost pressure as it is cylinder pressure/horsepower. Alot of aftermarket pistons now are using 4032 high silicon alloy's which are low thermal expansion compared to what used to be used, which was 2618. The piston to wall clearance when cold is alot looser compared to what you can run with 4032. As the cylinder heats up, the piston expands, which closes the gap on the rings, these are things you must account for with custom engine building. Along with bearing tolerances etc. Build it to factory spec and youll be fine.

I did some research on this topic. The IE Mahle pistons are made from 142P alloy, which seems to be the best of both 4032 and 2618. According to Mahle the ring gap plays the big role in boost pressures, found this on there site.



Looking over the factory manual the wall clearance is .0018" or .001" with the Grafal coating. This seems tight - do you have any knowledge around this?
I've heard about a thumb of rule that you need .001" for every 1" diameter.

[Spawne32]

That's an entirely new alloy I haven't dealt with before, I would reach out to IE as they should have the spec required for those pistons. Last time I built a boosted 4 cylinder I used supertech pistons which were 4032 low expansion. If I recall off the top of my head, it was somewhere around .0045" (so Bore x 0.0045" for your top ring) but this was on a B series honda. Skirt type, coating, application and horsepower ratings anticipated play a huge factor in this. That should translate to a .00146" top ring gap, and .0013 second ring gap.

[Spawne32]

I'm seeing suggested piston to wall clearances for those alloy types around .0025". Reasonable assumption should be that it should be slightly larger than factory given the alloy differences and expansion rates, but not by much.

[qmulus]

Plan on doing everything in the head if you plan on keeping it a long time or are doing a performance build. I have had six VW/Audi TSI heads apart now, mostly because of jumped chains bending intake valves, but ALL of them had pitted exhaust valves at the sealing surface. If you are going for a performance build, get upgraded exhaust valves and plan on doing at least the exhaust valve guides. If the car was chipped or even just high miles you will probably notice that the exhaust guides are pretty cooked and likely worn. I have seen some stock engines with 130k and good guides, and then one with 75k that the exhausts were trashed.

As for your metal shavings, if it is aluminum I would bet that a balance shaft bearing housing is coming apart, probably on the intake side. This is pretty common. I had one engine where the engine seized and the pan was full of metal. It was all from the balance shaft on the intake side. My _theory_ is that the screens on the balance shaft housing oil feed ports get clogged with debris (carbon, coked oil, etc.), cutting off oil to the balance shaft, which eventually leads to it overheating eating the aluminum housing. You are going to want to pull the balance shafts anyway, so it should be obvious it that is the situation once you get there. Regardless, if you are rebuilding the engine, I would go with a new set of balance shafts and a new idler gear to go with it. That has a graphite coating to set the gear backlash and gets worn in to match the balance shaft gear.

Replacing the rods is a good idea, if for no other reason than to get the bearings with locating tangs that keep them from spinning. I have seen three with spun rod bearings, all on #3 for some reason. The upgraded rods and bearings is probably the best thing to do on performance build.

The "wear" on the skirts is nothing. That is the Grafal (graphite) coating. It looks nice and evenly worn. Those are not the latest pistons. The newest have different oil control rings.

Finding the cam bridge screen there is pretty common. I also often find parts of them in the vacuum pump oil feed restrictor at the back of the head. Definitely check that screen (as well as the ones in the balance shafts housings) for debris.

What you are doing is overkill for just a K04 build, but should give you a fairly bulletproof engine. Well, as bulletproof as these things can be anyway. Oh, I would also recommend replacing the oil cooler. I have seen them get clogged on both the coolant and oil side. I only found that when I when to ultrasonically clean them and found that even after cleaning they didn't flow well. Compare it to a good one and you see a big difference.

FWIW, I am doing basically the same thing with an engine that I have. I bought the IE parts that were being sold in the classified here.

[linet90]

Great info. I haven't disassembled the head yet to know the condition of the valves. However, I do have some scoring on the intake cam journal and shaft, 4th cylinder. The car is still young in terms of mileage, 60k. I plan on doing more autocross which will drive high RPM conditions. Either way the valve train will be rebuilt.

I have the balance shafts out but no wear and tear observed. The shaft housing also looks fine. I haven't found any additional metal in any of the filters. The shavings look like machining chips, as if someone did a thread repair (which hasn't been identified either).

Luckily the rod bearings did not spin. Upgrading the pistons and rods was really a snowball affect. I knew the fix to the oil consumption issue was a redesign to the piston. Unfortunately, when buying the revised piston you also need new rods since the wrist pin was increased to 23mm. So going IE was actually a lower cost option.

It definitely is overkill. But the motor will be ready for the big turbo pushing 700hp, if I ever decide to go full race car. Great to hear about your build - what's the background story?

How would I know if I need a new oil cooler? I am also looking at adding some additional gauges, any thoughts? I currently have a boost gauge and am thinking wideband and oil pressure.

[linet90]

It has been a very long time since my last post and I have tons of scope creep to share.

First, what's been going on...

I did some paint work - engine block, sub box, and rotor splash guards.

The engine block was a pain and toxic. I highly recommend wearing a respirator, even when working outside. I started using an aircraft paint remover, purchased from my local auto parts store. This gave me very marginal results. I ended up getting POR-15 stripe gel which did the job quite nicely. With a SS wire brush, my garden hose, and multiple gel applications, I was able to get 95% of the paint off. After that exercise the block was off to the machine shop.

Image before paint removal:



Post machine shop:



Now I started prep for paint. I first used POR-15 cleaner degreaser followed by their metal prep. The metal prep did a great job etching the surface but significantly grayed out the surface (I call it dehydrated); this also discolored all of the shinny new machined surfaces.



After lots of masking, the primer was applied. I used a full can of Duplicolor etching primer as the metal was absorbing every coat, about 10 coats if I recall correctly.



To finish it off I Duplicolor engine paint enamel with ceramic:



Now to sub box. I build the box many years ago but I vinyl wrapped it instead. So...after some bondo, glazing, primer, base coat (matching my car color), and clear coat, I got this:



Crank and pistons are installed:





As for the scope creep. Beyond the engine work, I am not upgrading my brakes, rims, full suspension, headlight, LED tail lights, side blades, rain sensor, compass rear view mirror.

Brake upgrade: 345mm Front (Macan - Brembo), 330mm Rear (A6)

[dalmation53]

well you answered my question on the rods 23mm wrist pin to fit the updated pistons. looks like i'll be be buying rods as well.

Great info. I haven't disassembled the head yet to know the condition of the valves. However, I do have some scoring on the intake cam journal and shaft, 4th cylinder. The car is still young in terms of mileage, 60k. I plan on doing more autocross which will drive high RPM conditions. Either way the valve train will be rebuilt.

I have the balance shafts out but no wear and tear observed. The shaft housing also looks fine. I haven't found any additional metal in any of the filters. The shavings look like machining chips, as if someone did a thread repair (which hasn't been identified either).

Luckily the rod bearings did not spin. Upgrading the pistons and rods was really a snowball affect. I knew the fix to the oil consumption issue was a redesign to the piston. Unfortunately, when buying the revised piston you also need new rods since the wrist pin was increased to 23mm. So going IE was actually a lower cost option.

It definitely is overkill. But the motor will be ready for the big turbo pushing 700hp, if I ever decide to go full race car. Great to hear about your build - what's the background story?

How would I know if I need a new oil cooler? I am also looking at adding some additional gauges, any thoughts? I currently have a boost gauge and am thinking wideband and oil pressure.

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[linet90]

well you answered my question on the rods 23mm wrist pin to fit the updated pistons. looks like i'll be be buying rods as well.


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Glad to help. Here is also another source: https://www.ecstuning.com/b-genuine-...h/06h107065dm/

[EvolutionArmory]

How much material did the machinist take from the block? Make sure you add that measurement to the head gasket thickness or else your compression ratio will be higher than advertised. If he only skimmed .002 it won’t be a huge raise but if you deck a block, deck a head and use an aftermarket headgasket that is maybe thinner than stock, all those specs can add up to a noticeable raise in CR.

[linet90]

How much material did the machinist take from the block? Make sure you add that measurement to the head gasket thickness or else your compression ratio will be higher than advertised. If he only skimmed .002 it won’t be a huge raise but if you deck a block, deck a head and use an aftermarket headgasket that is maybe thinner than stock, all those specs can add up to a noticeable raise in CR.

I don't have the math to confirm what the delta is in CR. From what I know the deck was only skimmed to plane it, the head is new and the gasket is OEM. I will still be checking what my clearance is at TDC from piston head to deck.

[linet90]

How much material did the machinist take from the block? Make sure you add that measurement to the head gasket thickness or else your compression ratio will be higher than advertised. If he only skimmed .002 it won’t be a huge raise but if you deck a block, deck a head and use an aftermarket headgasket that is maybe thinner than stock, all those specs can add up to a noticeable raise in CR.

Your question really made me think this through. My pistons protrude past the deck as follows (values are an average):
1 - .0034
2 - .004
2 - .003
4 - .005

Found out that the OE head gasket is .035" thick which only leaves me .030" quench area. So, I need to get a head gasket .045" thick. Dodged a issue there. Thanks for the input!

[EvolutionArmory]

Don’t forget to account for any material that might have been taken from the head too.

[linet90]

Update:

Back to disassembly, I found a clearance issue on a main bearing cap nut. I am using ARP hardware; the nut flange was coming in near contact with the crank counter weight, see image below. As the thrust bearing wears it will create an undesirable interference. ARP was quick to respond and sent me a new set of nuts. I only replaced the outside cap nuts as I didn't want to replace the torque to yield side bolts for the center 3 caps. Plus, there is ample clearance on the inner caps and the extra surface contact is always nice. Now I need to reinstall the pistons and continue the build.

Clearance Issue Image


Clearance Fixed Image


On another note, my interior is almost entirely dismantled. I got some new-to-me sport seats and S4 trim panels for the headliner conversion. The fun part is getting the headliner out - I tried everything but the windshield needs to come out. Should be ordering the tools soon; lets see if I can do this without cracking the glass.

[linet90]

Need opinions on these head journals - this is a brand new head. Has anyone else encountered any recessed material conditions on the journal or casting seam line?

I'm hoping this is normal/ok to move forward with.



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