A number of people are shoehorning a 4.2 V8 lump into a B5, with the debate over a tuned 2.7T vs an NA 4.2. Is it possible to put an RS6 4.2T engine into a B5 or is the bay too small?
B5 S4 with 2.7T, 4.2 & 4.2T?
- Thread starter SonicDeathmonkey
- Start date
The RS6 engine WILL physically bolt to the 01E 6 speed, or 012 / 01A 5 speed in a B5, but it'll stick out a hell of a lot.
The RS6 block is shared with no other 4,2L V8 40V in the Audi range, the bellhousing bolt pattern is completely unique, so it won't bolt to a manual box, not without the use of an adaptor plate.
The spacer ring used between the AGB / AZR motor, and the 01E 6-speeder, is 11,2mm thick. The adaptor plate to mate the RS6 motor to the same box will be at a minimum, 30,0mm thick. More forward length, which you don't need.
The only way would be to build an RS6 into a regular 40V block, or start from scratch with a regular 4,2L n/a motor.
I'm going the S8 (4,2L V8 32V) route in my car, and once engine's in the car, and running, I'll decide what sort of exhaust manifolds I'll need to run a pair of turbochargers, in the available space.
I sold my modified S4 biturbo motor, in favour of the S8 one, as I'm a firm believer in not trying to reinvent the wheel.
Stick your hand in your wallet deep enough, and the V8 has far greater potential, as far as power goes. No substitute for cubic inches, regardless of what some sceptics may say.
The RS6 block is shared with no other 4,2L V8 40V in the Audi range, the bellhousing bolt pattern is completely unique, so it won't bolt to a manual box, not without the use of an adaptor plate.
The spacer ring used between the AGB / AZR motor, and the 01E 6-speeder, is 11,2mm thick. The adaptor plate to mate the RS6 motor to the same box will be at a minimum, 30,0mm thick. More forward length, which you don't need.
The only way would be to build an RS6 into a regular 40V block, or start from scratch with a regular 4,2L n/a motor.
I'm going the S8 (4,2L V8 32V) route in my car, and once engine's in the car, and running, I'll decide what sort of exhaust manifolds I'll need to run a pair of turbochargers, in the available space.
I sold my modified S4 biturbo motor, in favour of the S8 one, as I'm a firm believer in not trying to reinvent the wheel.
Stick your hand in your wallet deep enough, and the V8 has far greater potential, as far as power goes. No substitute for cubic inches, regardless of what some sceptics may say.
Blue_Thunder
Registered User
Some nutter in Greece is trying it at the moment:
http://www.audipt.com/forum2/index.php?topic=23422.0
He should get plenty of these if he gets it done
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siena: Wouldnt starting with a normal 4.2 be better for a turbo conversion? the S8 engine has raised compression ratio and probably wilder cams to get the extra power over the normal version and these generally dont go well with a turbo conversion?
do you plan to lower the compression ratio or try to turbocharge it with the 11:1+ that it runs stock?
do you plan to lower the compression ratio or try to turbocharge it with the 11:1+ that it runs stock?
Hi all , I'm putting a 6 speed manual in my rs6 .When in I'll have a spare 4.2 rs6 engine .I've also got a spare 4.2 fsi rs4 engine .
I'm developing new tubular manifolds and stage 1 hybrid turbos , then a nice set of big turbos when the 6 speed is on as there will be more space .
TBH i think the rs6 engine is look long to go in a b5 with out lots of work , the rs6 gets heat soak so i think it would be even worse in the b5.
I would tune a 2.7 tt insted of trying to fit a 4.2tt .
I'm developing new tubular manifolds and stage 1 hybrid turbos , then a nice set of big turbos when the 6 speed is on as there will be more space .
TBH i think the rs6 engine is look long to go in a b5 with out lots of work , the rs6 gets heat soak so i think it would be even worse in the b5.
I would tune a 2.7 tt insted of trying to fit a 4.2tt .
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siena: if your going to strip the S8 lump and fit the RS6 pistons and ABZ camshafts what benefit is to be had starting with the more expensive engine in the first place? Is the crank/rods/heads any better than the ABZ?
Also isnt the RS6 a 5v motor? do the pistons (valve cutouts?) fit ok with the 4v heads?
Are there any existing exhaust manifolds that will fit the ABZ and provide turbo mounting or is the best approach to modify the standard manifolds?
Me and a mate have been looking into turbocharging this engine so its good to be able to clarify some things we were wondering about!
i recon using an ABZ, keeping the boost levels sensible (~8psi max?) you could run two turbos (GT28RS?) on a stock ABZ and generate around 450hp pretty safely with mappable management. With proper boost control you could likely get more power at the stock compression ratio by keeping the midrange boost sensible as above and then increasing it as the VE of the engine starts to drop, proper mapping could generate a completely flat torque curve from the engine coming on boost to the rev limiter.
Also isnt the RS6 a 5v motor? do the pistons (valve cutouts?) fit ok with the 4v heads?
Are there any existing exhaust manifolds that will fit the ABZ and provide turbo mounting or is the best approach to modify the standard manifolds?
Me and a mate have been looking into turbocharging this engine so its good to be able to clarify some things we were wondering about!
i recon using an ABZ, keeping the boost levels sensible (~8psi max?) you could run two turbos (GT28RS?) on a stock ABZ and generate around 450hp pretty safely with mappable management. With proper boost control you could likely get more power at the stock compression ratio by keeping the midrange boost sensible as above and then increasing it as the VE of the engine starts to drop, proper mapping could generate a completely flat torque curve from the engine coming on boost to the rev limiter.
Aragon: I don't understand. Which more expensive engine?
I have 2 V8 engines: An ABZ, and an AHC, both 32V. The ABZ (300PS) is an engine I bought a while back, the AHC (340PS) is an S8 motor, I bought recently.
The RS6 pistons from the 5 valve motor can be used in the 32V version.
I am having S8 manifolds modified to take turbochargers.
I intend to lower the CR enough to run at least 12.5psi, still under a bar, and not over optimistic.
I have 2 V8 engines: An ABZ, and an AHC, both 32V. The ABZ (300PS) is an engine I bought a while back, the AHC (340PS) is an S8 motor, I bought recently.
The RS6 pistons from the 5 valve motor can be used in the 32V version.
I am having S8 manifolds modified to take turbochargers.
I intend to lower the CR enough to run at least 12.5psi, still under a bar, and not over optimistic.
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ah right! i presumed you only had the S8 motor, and was wondering why you'd have chose that over a stock ABZ when you'd need to swap out the cams etc anyway
if you were prepared to run on 98octane fuel you could probably manage the 12psi on the ABZ's stock 10:1 compression ratio?
if you were prepared to run on 98octane fuel you could probably manage the 12psi on the ABZ's stock 10:1 compression ratio?
Yes, 98 octane fuel would be my choice at that CR, running that much boost.
This sounds interesting! Are you also installing the 4,2L V8 into a B5?
This sounds interesting! Are you also installing the 4,2L V8 into a B5?
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My mate is looking at fitting the engine and the turbos to a B5 quattro, i was considering it as powerplant for my Land Rover 90 (without the turbos though) although money being the mega limiting factor at the moment for both of us.
My 90 is currently undergoing a ground up rebuild on a new galvanised chassis and i've been looking at the figures and realised the V8 is the better option: TDI will do around 30mpg with fuel being around £1.20 a Litre (and climbing fast), a Rover V8 on LPG will do 15mpg with fuel around 50p a litre. It currently has a TDI but seen as the audi motor is going to be much more fuel efficient than the crappy old rover engine then its going to be doing >>15mpg on gas while making twice the horsepower the rover engine made!
The only tricky part will be fabricating a bellhousing adaptor to mate the Landrover gearbox to the audi motor.
My perfect a4 would have to be a late model B5 quattro sport with a 4.2L V8 with or without the turbos, however until the missus finishes uni its going to have to sit on the back burner as i just dont have the spare funds at present.
My 90 is currently undergoing a ground up rebuild on a new galvanised chassis and i've been looking at the figures and realised the V8 is the better option: TDI will do around 30mpg with fuel being around £1.20 a Litre (and climbing fast), a Rover V8 on LPG will do 15mpg with fuel around 50p a litre. It currently has a TDI but seen as the audi motor is going to be much more fuel efficient than the crappy old rover engine then its going to be doing >>15mpg on gas while making twice the horsepower the rover engine made!
The only tricky part will be fabricating a bellhousing adaptor to mate the Landrover gearbox to the audi motor.
My perfect a4 would have to be a late model B5 quattro sport with a 4.2L V8 with or without the turbos, however until the missus finishes uni its going to have to sit on the back burner as i just dont have the spare funds at present.
