Diesel bore and stroke: 79.5mm X 95.5mm=2371c
Gasoline bore and stroke: 81mm X 95.5mm=2461cc


<img src="http://pictureposter.audiworld.com/41804/eurovan.jpg">

The AAF is the older 2.5L, the ACU was used in the final two production years in the USA. Low CR motors I think, they only made 110hp, but a fairly broad torque curve, peaking at 150-something.

regardless of being gas or diesel. So, that isn't a problem. However, the 2.4L AAB diesel has tiny holes, 79mm, so you'd want to punch it out to at least 81mm, which is where the AAF/ACU gas motors are at from the factory.

All of those blocks can take 82.5mm to 83mm pistons for even more displacement. You may want to have the head massaged a bit for the added displacement (more air flow), and run a different turbo. Going from 2226cc (81x86.4) to 2460cc (81x95.5) or even 2553cc (82.5x95.5) and the slightly bigger 2584cc (83x95.5) is a pretty big bump in displacement.

I'd get new rods (pauter, carillo, eagle, someone!) and pistons (JE, Wiseco, etc) to make sure things are turbo friendly.

I know we talked about this before: 034 EFI, with serious port work, 35mm ex, 7mm stems, 83mm 10.:1 custom pistons= 180hp and 200lb.ft of torque????????

does anyone know if a 20v head will bolt up? i wonder what the corresponding CR would be....

I'd maybe think about doing some stress relief on the rods, I may do so even on my MC-1 rods. Basically just clean them up, that way there are fewer places for cracks and such to start.

You'll be pretty darn happy with the results from a stroked 10v. I know someone who is just about ready to pull the trigger on a 2.5L 20v setup, shooting for 210hp "easily" according to the head/machine shop guru he's sending his 20v head to. He's just going to run some sort of piggy back controller, so we'll see what is going to happen power wise for him.

If you want to run 7mm stems, start rounding up bits from the AFC code 12v V6. That engine also has lighter hydraulic lifters, and a lighter valve train in general (single spring setup versus the older dual spring setup). One of the several reasons why they are so darn smooth and rev so easily.

Engine Specifications
2.5L 109 hp I5
Horsepower 109
Torque (lb-ft) 140
Valves/Valve Configuration No data
Displacement (cc) 2461
Bore X Stroke (in.) 3.19 X 3.76
Compression Ratio 8.5:1
Fuel Type/System No data
Turbocharger No
Supercharger No

How far can you go with a 2.3? I take it the 2.5 has a longer stroke.

I am back an forth beween a 20V N/A and a MC1 or 2.

And even turbo'd them. I wouldn't take that risk myself.

There are three 5cyl strokes:

86.4mm - stock, 136mm or 144mm rod lengths depending on engine

92.8mm - only seen it used in a very small handful of Audi Sport/Kolb 2.48L 20v "7A" motors, not sure of rod length

95.5mm - All 5cyl Eurovan motors use this, 159mm rod length

Pretty much all of the iron blocks can be punched to 83mm safely even with turbos. With a proper head, a 2.48-2.58L motor will work pretty well, lotsa torque and good horsepower. The 2.5L 10vt dyno charts I've seen were rediculus. HP was average, but the torque was insane.

if so i'm just curious how accurate they are....

now if we can find out combustion chamber volume....hmmm. i'd bet that you could turbo that engine with out lowering the CR since the MC2 is the same CR and damn near the same combustion chamber design, if not a little better since it's newer.

i better just go yank that engine at the yard...sinece they only want $130 for it complete! then i can just start playing with options..... :-)

engine? Shorty pistons to clear the lower block height obviously.

Better to just run the tall block and long rods.

Audi did manage to get the 92.8mm throw crank to work in the shorter, normal 5cyl block however...

AW would not have the specs on that motor, and if they did, I wouldn't trust them ;-)

$130 for the 2.5 gas motor is pretty good. The head is really goofy, and isn't designed for a lot of flow at all. You'll have to stick a ported 10vt head on it.

we'll see how this project goes....!!

included a crank/rods/pistons, and used a shorter block?
what did that kit accomplish?

<ul><li><a href="http://www.eurospecsport.com/stroker%20comp.htm">Stoker kit 4 Valve 5 Cylinder</a></li></ul>

I don't think it rev'd quite as well or quite as high, and I thought one kit had a spacer included?? They used to have different pictures up of it...

i'll go DL messenger..i used to have it because 1 friend had it, and he quit using it.

i gotcha added to my list....i'll try and catcha sometime when youre on.

Out of curiosity.