2.5l upgrades for the NA I5

[Jukka Majanen]

Hi all

Mihnea wrote:

>I've just done some mathematics and geometry today to see if a 2.5 crank 
>coud fit in a 2.3 block.
>This 2.5l engine uses a 82.5 mm bore size with a 92.5 mm stroke. As opposed 
>to the 86.4 stroke for the 2.3.

Right on, if You want to reach 2.5/2.6 AAF engine You have to chance 
the crank to get that displacement. What I have heard; that engines
bore is 81 for 2.5 and 82.5 for 2.6 and the stroke is almost huge, S/D 
will be almost 1.2.

This 2.5/2.6 is just a tractor engine and the crank/wheel is too heavy to
run well, chancing them is not satisfactory, really. What You get with
10% extra displacement You will loose at the "move" and badly....

#1 An American Bighearted Audi was a disappointment
#2 Some 20vT guys found same thing and switched back to 2.2

>The problem that resulted was that either the stock block is 5mm too short 
>to accomodate for the longer stroke or stock rods are 5mm too long.
>The distance between the holes in the stock rods is 159 mm for both engines.
>What could be the solution?
>Cutting/rewelding the rods? "Prolongate" the block? The latter seems pretty 
>much like Sci-Fi :))!!!

Of course You can put there lower pistons with $$$$$, but still it is Sci-Fi.

jiipm at sci.fi :)))

j-pm