Hey
I have a few questions that are maybe easy for someone to answer if they've got a minute, and don't mind :)
I have a NF engine from 87 5000s Quattro, and a MC turbo from a 86 FWD Auto. I realize the heads are different, but is the lower part of my block the same as the MC block ? Ive pulled the head off the NF but not the MC yet. My pistons in the NF seem to have a little bit of play (about enough to slide my fingernail in) towards the left<-> right direction, but not front to back of block. (Can be felt by just pushing that side of the piston down). Anyways Im thinking of doing a Block swap if the blocks are the same, as the MC turbo block only has 138,000 Kms on it, and makes it a good choice.
Can anyone tell me if the blocks are identical, or if it will work ? I know the MC setup has a lower compression ratio, 8:1 , or 10:1? the Nf might be 12:1 ? I'm not sure exactly. Im guessing that they will not be, but Id like to check, as the NF head is used in some turbo cars, as Ive been lead to believe...

Thanks for any info,

But isn't that just in the head and the volume in the cylinders? (How far the head is raised up from the block, grind it down for more compression?) or the actual block has shorter piston travel ?

edit: what im getting at is that the head is whats responsible for the different compression?

Thanks

Why not take the whole MC motor, turbo and all, and put it in the quattro?

Seems like a much better / easier plan, no?

(In Dundas)

That was an idea I had, but I don't have the time to do the swap. I guess there is no time like the present to start rebuilding the turbo :D.

Thanks all :)

Hmm

What about boring out the engine. If Im going to do the rings, I may as well do this, as im in search of more power, without a turbo for the moment. Maybe to 2.5L ? Does anyone know the maximum size?

Ive also seen a little bit of talk about an ECU mod for the NA cars. Does anyone know much about this ?

Thanks

83mm is what Audi stops at for the NA engines. One or two people have gone to 83.5mm on turbo engines, which is quite a bit.

To get to 2.5L you have to get a different rotating assembly, and depending on that assembly a different block even (taller).

I find it hard to believe, unless your NF has well over 200k miles, that there was much side loading. Naturally aspirated 10v's have minimal side loading, unlike the turbo models. The NF I'm working on is out of my 180-200k mile range 5kq, NO ridge in the bores and no excess play. First owner was a woman, I was the 2nd and 3rd owner (was hit by a Jeep, ins buy back). Seeing as though I got the car when I was 17 (turn 26 in a few months), I was not easy on it but I have taken care of it...

Hmmm

Thanks for the reply. I'm not sure why its wearing like this then, like I said theres no ridge or scratches in the bores, just play when the piston is at TDC. Seems rather strange. I've got another block from a car that I'll check out and see if it acts the same. (with the play). I don't abuse the engine, at least not to me, anyone else here take their NF to 6000 rpm often ?

How much damage did the car take from the run in with the jeep ? They feel pretty solid, and have real bumpers. Just curious...

The pistons are ground tapered being smaller diameter at the top. The "slop" goes away when running at normal coolant temps.