Though the B6 S4 headers are very similar in construction to those fitted to the D3 A8 V8, they are different internally. The D3 headers are geared more towards comfort, and quieter operation. The B6 S4 headers are sportier, which is one of the reasons the B6 S4 has a gruffer V8 rumble, the D3 4.2 V8 is almost silent in comparison.

B6 headers were in good shape, just needed some of the "treatment" to get the stainless steel gleaming. Damn A1 A2 German! Now everything on this engine's got to be either polished, or painted, haha.

B6 headers, as delivered. A bit discoloured, but at least being stainless, they polish up good:





I clamped the first header in my bench vice, and got to work with a selection of rotary brass wire wheels / cups:













The partially finished result of one header versus the untouched one. I say partially finished, as I'm picking up some stainless steel polish, to get them to the same mirror-like finish as my B5 S4 stainless exhaust system:

















A close-up:

 

I have been looking at clutch options for my B5 420-R.

Whilst I don't want to install a clutch that will slip when driven in anger, I don't want a clutch combination that will make the car nasty and snatchy to drive, especially in traffic. Remember, this is a street car, at full weight. The heavier a car is, and the greater the torque the engine generates, the less compatible a race-style, or paddle clutch will be.

Paddle 6/8 PUK friction discs are grippy, but they're not kind to flywheels, it's not unusual to find a flywheel chewed up pretty bad after 30,000 miles of driving.

Heavy cars are not nice to drive either with lightened flywheels, or crankshaft pulleys, which is why though my flywheel is lighter than that of the B5 S4/RS4 or 30V, it still has a decent weight to it. Aluminium flywheels are bad news - not only due to the extreme light weight, but the very construction.

A steel insert against aluminium, secured with rivets. We're talking 2 different metals against each other, with different expansion rates. There have been quite a few cases with B5 RS4's, S4's and big-power 1.8T's, where there has been slight slip, enough to generate heat, causing the steel insert to warp, pulling the rivets out of the steel.

I have ordered a genuine B5 RS4 clutch from my local dealership. Like most modern Audi models, the clutch is NOT available from Audi as a kit, you purchase the parts individually. So pressure plate, friction disc and throw-out bearing.

The B5 RS4 runs the same components as the B5 S4, with the only difference being the pressure plate. Same construction in both cars, same profile. However, the B5 RS4's pressure plate has a stiffer diaphragm, meaning the clamping load is significantly higher. I'll have the lot with me by Tuesday. I can then complete the necessary modifications to allow the 01E transmission to mate properly to the D3 BFM V8 motor.

Just in case anyone's interested, the part number for the B5 RS4 clutch pressure plate is 078 141 123 G.

 

I got my second B6 S4 header cleaned up today. Then gave both of them a polish with a proprietary metal polish. My favourite brand has always been Autosol, and was my weapon of choice here.





















B6 S4 headers, de-cat downpipes and B5 S4 cat-back exhaust:

 

Update: 16th September, 2015.

My clutch turned up today, together with a pair of exhaust manifold gaskets.

The beauty of Audi selling most current model clutches as individual parts rather than as kits, is you can pretty much mix and match. I went with a B5 RS4 clutch pressure plate, but opted for a friction disc for the B6 3.0 TDI Quattro, though it is listed for some other models. The TDI friction disc is marginally thicker than a stock B5 RS4 one, and more heavy duty.

The throw-out bearing will be with me tomorrow at some point.

Pictures!





With single-mass V8 flywheel. I'll measure the stack height once I purchase a set of bolts from Audi, and it's all bolted together:







The standard flywheel bolts from the A8 are obviously too long, so I need to get a new set. The ones for my 30V flywheel will work, but given the torque that needs to be applied when tightening these bolts, I would feel more comfortable knowing they were new, and unlikely to let go at 7000rpm.

Gaskets:

 

My low-coolant level warning came up on my DIS this morning. A check showed the coolant was indeed low, and I topped it up.

On my return from work, I noticed a dripping underneath the engine area. Too far forward for it to be the climate control drain, or water pump. Some of you guys may have guessed it - a bust radiator. After 15 years of service, it finally sprung a leak from the lower left-hand end tank.

One thing is certain - I'm NOT pulling the bumper to replace it with an aluminium one. Looks like my V8 swap will happen much sooner than I originally planned.

 

I bolted my B5 RS4 clutch assembly to my bespoke V8 40V single-mass flywheel, so I could measure the stack height. Very comparable with that of my DTM car, which will be running a different set-up, an OEM European D2 S8 flywheel and clutch.

D2 S8 flywheel and clutch stack height, 85.0mm:





Bespoke V8 40V flywheel and B5 RS4 clutch stack height, 85.5mm:

 

I began work on my BFM V8-to-01E mating this morning.

Some parts have been ordered, and by next weekend, I should be able to bolt the engine and transmission together. Just working on the starter motor.

It's looking good.

 

Update: 24th September, 2015.

I originally planned to retain my original 30V radiator, but it sprung a leak a few days ago. It's sealed for now, but do I truly want to cool a big V8 motor with a 15-year-old radiator?

I had previously purchased a B5 aluminium radiator for my 32V S8 motor, which was installed in my old 1995 B5 2.6 V6 12V Quattro, but that was adapted to that engine.

This time, with my 40V D3 BFM engine going into an '00 B5 2.8 30V Quattro, I intend to keep the coolant hoses in their stock positions, on the right-hand side. So I ended up pulling the trigger on another B5 aluminium radiator. Unfortunately, there's no B5 that has both upper and lower coolant hoses on the right.

I could flip the radiator, but then that messes up the lower mountings, as well as the integral brackets for the air conditioner condenser. I could also run aluminium radiators for the VW Golf MK5, or probably a B6 S4, but again, these solutions are pretty gash. I've gone for a different, and dare I say cleaner look.

I'm getting the radiator coolant inlet and outlet pipes cut off, and transferred to the right-hand end tank. The holes left will then have aluminium discs welded in place. This arrangement will keep the original coolant hoses of the D3 40V stock, for a more OEM look.

I should have the radiator with me sometime next week.

 

Update: 26th September, 2015.

A big box arrived today, via DHL:



Containing my aluminium radiator. Very well packaged, it's actually a branded item, FENIX. The build quality is streets ahead of the one I purchased for my 32V, and is reflected in the price, 4 times more expensive. The one I purchased previously is a Chinese-made item.

As I previously posted, I am getting the inlet / outlet connections moved to the right hand side, to match the D3 V8 40V hoses. The plan was to have the original connections cut off, circular aluminium discs welded over the redundant holes, then get the stubs welded into the right hand end tank.

Looking closely at the radiator, I have decided to just cut down the inlet and outlet connectors, leaving a generous stub. My reasoning is simple - aluminium welds are fairly substantial, so going with a flush cut may not be the best solution. This means the stubs may be too short to install on the opposite end tank. I opted to order a new pair of aluminium inlet and outlet connectors, in the same size. These will be with me sometime next week.

Radiator pictures. The radiator manufacturer actually supplied a catalogue, listing their other products. They also produce heater cores, intercoolers, condensers and lil coolers:

















32mm aluminium inlet and outlet connectors:

 

Update: 29th September, 2015.

My starter motor turned up today, along with my flywheel bolts and a B5 A4 I4 front crossmember.

Anyone who has tried mating a C5 RS6 V8 Biturbo to an 01E will know it's not a bolt-on job. Only 4 bolts from the upper block will mate to the corresponding bolt holes on an 01E, the automatic flexiplate is much larger than any flywheel that will fit within the confines of any Audi manual gearbox. And of course, the RS6 starter motor will not work with the correct size flywheel.

So complications is an understatement.

There is the chunky adapter option, and a custom starter motor, options that don't interest me in the slightest.

I now have a factory starter motor that fits the D3 V8 / C5 RS6 block. Is the starter motor modified? No. Is the block machined to accept the starter motor, and extra holes drilled to match? Yes. Is this safe? Absolutely.

I shall bolt the flywheel and clutch to the engine over the weekend, do the last bits and pieces, then mate the motor to my built 01E.