Differences between 2.8 30v / s4 engine

[205man]

Apart from the obvious turbos etc, how much different is the 2.8 30v engine to the s4?

Does it share any common components etc?

The reason ask is that I know that you can fit the crank from the the b6 a4 into the s4 making it then a 3l bi turbo, but will it fit the 2.8?

My mates garage had to order a new 3l crank but due to mix up got 2 so if it will fit then he will let me have it , if not he got someone with an s4 interested

Thanks Alan

 

[aragorn]

yep, the block is in effect the same.

You need "special" pistons afaik though designed for the 3.0 crank in your shorter block.

 

[205man]

Thanks for that ... Well it looks like a plan to me, so I will be tracking down some pistons then by the looks

 

[Talkwrench]

There is also a lack of oil squirter's & the crank main caps are also very different in the 2.8 when compared to the S4 motor. But if your just stroking the NA 2.8 to 3.0 it wont matter :icon_thumright:

 

[WickedA454]

what if you wanted to put a supercharger on your 2.8 which block would be better suited for a built supercharged engine

 

[aragorn]

Given the S4 motor was designed specifically for forced induction, its probably fair to say its a better basis for a forced induction engine.

That said, if you've gone out and baught an S4 motor, why bother supercharging it at all!

 

[WickedA454]

cause id rather go the other way on this and supercharge it.
buti know a couple yards that will only charge 100 bucks for the motor if i pull it myself saying that someone around here junked there s4

 

[Talkwrench]

Your gonna junk the turbos & supercharge an S4 motor? Why would you do that? Just supercharge the 2.8 it wont make enough power to warrant an S4 motor, if you went through the trouble to fit an S4 motor you would be better holding on to the turbo setup, much more power available.

 

[WickedA454]

so the s4 and 2.8 don't mount the same way i take
even if i built a 2.7
stroked it
special pistons
performance heads
a g1 supercharger
smaller pulley
and other good stuff
i could still have more potintial from the s4 motor

 

[Talkwrench]

They do mount the same way, they do use different gearboxes and rear differentials, drive & prop shafts, subframes etc. My point was if you want to supercharge the V6 just use the 2.8 you have in the car. If you wanted to go through the pain of fitting the S4 motor & drivetrain to your A4 then stick with the turbos as it will be more powerful, easier to tune, more aftermarket parts etc etc.

 

[WickedA454]

gotcha thats what ithought