Audi B5 420-R: The Build

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 12:56 pm

And here's how the Santorin Blue car now looks, wearing the same OEM 16" wheels as the Pelican Blue Audi:

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 12:57 pm

Thanks for keeping up so far guys.

Today I finally liberated the 4.2 V8 40V from my old 2005 Audi A8 D3. It's on the bench now, I've removed the automatic flexiplate.

It's quite different from the V8 from the D2 A8/S8, C5 A6/S6. It has more in common with the V8 from the B6/B7 S4, just without the nasty multiple chain set-up that is so failure prone, worse because the timing chain is at the rear of the engine, and replacement requires an engine pull. Urrrrgh!

A lot of chassis plug mods will be required. I'm going to build a hybrid section to plug into the B5. Pictures to follow, once I've had a shower to rid myself of the grease and grime, and had something to eat too.

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 12:59 pm

Update 04th July 2015:

So the D3 A8 V8 engine is out at last.

I'm going to do some basic maintenance. I replaced the timing belt less than 2 years ago, together with the thermostat, all tensioners / idlers and the water pump, so these will remain.

However, I'll pull the valve covers, and renew the gaskets, probably get them painted. I'll also remove the timing belt covers, and clean them up. Generally all aluminium components will be thoroughly cleaned, and painted the same colour as OEM - aluminium. I've ordered a new engine stand, so I'll wait till it turns up, so at least the motor is easy to rotate.

For flywheel, I can either use my stock 30V one, or order a solid steel B5 S4 item, and run a B5 RS4 clutch. This car is being built for the street, so luxury and comfort are important. Unlike my other B5 which will be a stripped-out racer, possibly with forced induction.

Some pictures of today's progress. It took me 3 hours from start till wrap-up time:

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:01 pm

My A8 D3 4.2 V8 (BFM) electric wiring diagram PDF turned up. I now need to build a hybrid harness between the D3 engine harness, and the B5 chassis plugs.

I don't intend to cut off the D3 chassis plugs, I'm removing the D3's receiving connectors with a reasonable length of harness, to which I will solder the B5's plugs to on the free ends, moving the wires to the relevant pins.

It's PDF time!

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:02 pm

Although I can run the D3's ECU, I have decided to go with a 2002 C5 S6 ECU. It has a more aggressive tune as standard, when compared to the milder, comfort-oriented D3.

To this effect, I've just pulled the trigger on an S6 ECU.

The S6 ECU also has the added advantage of being able to accept a manual soft code, which the D3 A8 never had the option for.

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:04 pm

Update 16th July 2015:

I did some minor maintenance on my BFM motor. The left bank valve cover gasket had a slight oil leak at the rear, so I decided to replace both.

Both valve covers are in great shape, with just the smallest hint of the usual aluminium corrosion on the inside, close to the last retaining bolts. I am considering getting both painted in a body shop, but I'm kind of debating whether I should stick with the OEM Audi silver, or go with Pelican blue. Both will contrast well with the red coilpacks.

It's surprising how clean an engine can look in the bay. Mine looked great, but lots of hidden grime became evident once it was pulled, and bolted to my engine stand. I obtained some engine degreaser - the professional stuff used by auto valet / detailing shops, rather than the rubbish foam in a can. 40 minutes later, it came up pretty good.

Now that it's all clean, I'm tempted to keep the valve covers grey, just get them refreshed. Could anyone photoshop them Pelican, or close to Pelican blue? It'll give me an idea how the engine would look.

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:06 pm

Since I have opted (as always) to run an 01E 6-speed, there is one vital ingredient missing. I've got a built 01E from a 2001 S4, B5 RS4 propshaft, shifter from the same car. However, I don't have the correct rear differential.

My 2.8 rear differential is a 3.89:1. The 01E final drive is 4.11:1. The only B5 gasoline model this side of an S4, with the correct final drive is a 2.6 V6 12V Quattro. So that's where I'm concentrating my search. A B5 S4/RS4 single mass flywheel has been ordered, with a hybrid clutch set-up. RS4 pressure plate, with a sprung hub 240mm friction disc.

To begin modifying the D3 A8 engine harness, I would prefer to purchase an engine harness from a 2.8 30V DBW (same as mine). This is mainly because I don't want to ruin the harness in my car, as I would rather sell my APR 30V motor complete with the ECU and harness. This will also allow me to build the hybrid harness without taking my car off the road.

This weekend, I'm going to pull the receiving harness from my D3, the section the engine harness plugs connect to. At least, I can start labelling the wires, ready to solder to the APR connectors.

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:07 pm

Just a quick photoshop, courtesy of MetalMan, from another forum. My mind's pretty much made up to have the valve covers painted in Pelican blue, to match my car:[/color]

What do you think guys - have the valve covers repainted in the standard grey / silver, or Pelican blue?

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:09 pm

In the past, when I have carried out V8 swaps, with the exception of just 1 (I have done 4 since 1999) my method has been to throw the motor into the engine bay, then sort out the wiring later. The exception has been the one swap I carried out, with aftermarket ECU and custom built harness.

This time, I am doing things differently. I am building a hybrid engine harness. Remember, I am using a different motor to what I'm used to - a 4.2 V8 40V from a 2005 Audi A8 (BFM). And as such, the factory harness has absolutely no relationship with a B5 chassis. Neither is it remotely related to the harness in a B6/B7/C5, which are closer to that of the B5. At least, the C5 is.

To this end, I have just purchased an engine wiring harness, from a 2000 B5 S4. This should be with me by the 21st July 2015. I will then cut it up, using it as an "adapter" to mate the D3 harness to the B5 chassis connectors. The D3 harness plugs also mate to the chassis connectors on the left, while the same in a RHD B5 are on the right. I will be using the D3's chassis connectors and a length of the harness to make up the desired length. So making the hybrid harness plug and play into a full facelift B5.

Some may ask, why not simply use my APR 30V harness, instead of buying an S4 harness? The answer is to avoid what most of us don't like - excessive downtime. I can keep my Pelican blue B5 30V Quattro as my daily, right up until the time comes to install the BFM V8 in the bay. In theory, I could bench run the V8, before the swap, since there's no immobiliser to contend with. I could have used any 2000-2001 B5 harness, the S4 one just came up at the right price.

I have purchased the correct black cloth electrical tape, to match the Audi's OEM insulation, and I'll post pictures as the harness work commences.

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:19 pm

I pulled my valve covers last night, and dropped then at the paint shop this arvo. They should be ready by Thursday.

In the meantime, I'm going to start cleaning up the aluminium components. I would normally have to sand down rusty steel components, and then paint them. Or even replace if badly pitted. In this case though, there's no rusty steel, the engine is pretty clean. The only steel parts that need attention are the crank pulley, and a couple of the idlers.

Even the starter motor looks like new.

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:21 pm

Update: 24th July 2015.

I got a call from the paint shop, whilst still at work, that my valve covers were ready. So it was a bit of a crazy rush to drive there during my lunch break, to pick them up.

I'm pleased with the finish and colour match. These will be refitted tomorrow at some point. I am going to start on the aluminium components on the engine. I figured if I buffed them to a clean state, it won't be long before they go dull again. So I have opted to paint them in the original aluminium silver once they're cleaned.

I was also lucky to stumble upon a set of front and rear brake rotors and pads. The rears are no good to me, being for a FWD A4, with bearings, ABS rings and pads. I'll sell them on.

However, the fronts are a bit more interesting - the rotors are D2 A8 312mm items. I just need to purchase a set of Audi A6 C5 or TT 1st gen. front caliper carriers, then they're ready to bolt up to my B5. These are temporary, as I will be running B5 RS4 360mm front rotors, with Brembo 4/6 piston calipers.

Some pictures:

D2 A8 312mm front rotors, and OEM B5 V6 pads:

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:23 pm

Update: 26th July 2015.

I have just installed my freshly-painted valve covers, cleaned and painted some of the aluminium. I have not bothered polishing the air con compressor, as I won't be using it. The D3 A8 aircon compressor is the variable displacement type, while the B5 A4 V6 is fixed displacement with a conventional magnetic clutch. So I will be installing the B5 compressor in the same location.

The same goes for the D3 A8's combined oil cooler and filter housing. The D3 runs a paper oil filter element, while the C5 A6/S6 is a conventional metal spin-on canister, which I prefer. More importantly, the C5 V8 A6/S6 housing integrates the right hand side engine mounting bracket, so I'm going to use one of these.

Some pictures:

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:26 pm

Colour matched pretty well, considering the car is 15-years-old, and it's never had a respray:

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:31 pm

Update: 27th July 2015.

Today, I discovered how different the 4.2 V8 from the D3 A8 Quattro (BFM) is more different than I thought.

It IS an 077 series V8, on the surface, it appears to have more in common with the 079 series V8 in the B6 S4, obviously without the B6's garbage multiple chains. Similar intake plenum, fuel rail, coil packs, exhaust manifolds.

But this is where the similarities end.

The 4.2 V8 block from the D3 A8 is actually based upon the 4.2 V8 Biturbo from the C5 RS6. The RS6 V8 has a block which is unique to it's application. At least it did until the D3 cars were produced.

The RS6 C5 V8 has a larger block, where it bolts to the transmission bell housing, to accommodate the much larger torque converter, which is shared with the W12 Audi A8 and Volkswagen Phaeton. I spent the day comparing the RS6 and D3 V8 motors, and the rear ends are the same. Down to the casting marks on the sides of the blocks, they came from the same cast. Same bell housing bolt patterns that need some fettling to mate them to an 01E.

I will be posting pictures as I proceed, this will be of help to someone else here who is also looking to run a BFM V8 in his B5.

Nollywood · Post by **Nollywood** » Sat Oct 03, 2015 1:33 pm

Update: 04th August, 2015.[/color][/b]

I ordered an engine cradle, and it arrived today. My A8 4.2 V8 has been on my engine stand. Fine for working on just the motor, but it sucks if you wish to bolt the transmission to the engine.

I need to bolt the engine and transmission together, to sort out some of the bolts. Remember, the BFM motor shares its basic block structure with the 4.2 Biturbo from the C5 RS6, meaning some work is required for 3 bolts that don't line up with the mounting holes in an 01E 6-speed manual.

I also purchased a scissor transmission lift, and it was delivered today too.

Engine cradle: you can actually use it as a test rig, if you wish to run the motor out of the chassis.

Transmission scissor lift: