2.5l conversion

[Firebird69]

Anyone drive a 2.5l conversion in an 2.2 S2- or UrS Block? (AAN, ADU, ABY, 3B).
I plan to build an engine like that...can I use a 2.5l diesel crank out of an Audi 100 or Volvo or do I need a race-crank...I think they are pretty much to same?

what is your experience?

are there any threads on here about that which I just didin't see

[Rusty]

There are quite a few stroker threads. Start with RWD19T's, Jamo's and AndyP's and I'm sure yo'll find plenty of links from there. Crank is diesel for 95.5mm, race for higher, you'll also need to decide whether to use the OE block or diesel block and that will affect most of the rest of the build... until you get to turbo choice and then mapping... it's a nice dream and most on here will have had it at some point but it usually stays in the 'if I won the lottery' part of the brain. Good luck if you do go down that road, I'm sure it'll be fun

[Jamo]

The 2 must read threads are:

http://www.s2forum.com/forum/showthread.php?t=4910

http://www.s2forum.com/forum/showthread.php?t=6797

Then you have mine, AndyP, RWD19T, Audi_CQ there are a load of them on here.

[Firebird69]

thanks a lot Rusty...the thing is mostly I'm woundering if it is a good Idea to use the nice AAN that I already have??

[Jamo]

Using AAN 220mm block? It can be done things to be aware are high piston ring wear rate, steep rod angles and short compression height required on the pistons

If you can source a 92.8mm crank that is the best route for 2.5/2.6 l in the AAN block

[Firebird69]

thaaaaaaank you so much...

[Firebird69]

Thanks Jamo...I already got JE-pistens reg. compression for my AAN 81.5mm bore. Do you think I should get diffenert pistonsrings for them or use original? Pistons should work I believe......... so finding a 92.8mm crank and some good rods are the mission now I suppose? and get a stiffener plate for the block...

[Jamo]

You need custom pistons for either setup you cant use OEM pistons, some claim you can but the CR is too high

[Firebird69]

hm...ok...I need to talk to my mechenic about that...so your saying lowering the compression with the head gaskat could not get low enough?

[Jamo]

That's going to be a big gasket

[Firebird69]

oh...you are right...I was planning on using shorter rods as well

[Billman]

about stock pistons and diesel block and crank

http://www.s2forum.com/forum/showthread.php?t=34352&highlight=stroker+rods

[Jamo]

He's not using a diesel block, he want to use the AAN block

[Billman]

aha! Then Jamo is right. This engine will not live very long.

[caterpillar]

92,8 crank are NOT so commen in audi cars... but in some eurovans with 2,5 l 10v petrol; the may have this item; not always...in some 4pot audis you have this in some audi 80 fx... but the crank doesnt fit 5 pot....8-))