Automobiles Forum banner

1988 90Q AAN Swap Project

16K views 55 replies 8 participants last post by  Spooky Quattro 
#1 · (Edited by Moderator)
Hello all, Im new on the forum and wanted to start a build thread to get some advice and hopefully connect with some people who might have parts I need.
Back in December of 2018, I acquired a 1988 90q 10v that has somewhere near 200k on it, the odo stopped working at 156k (I've never owned an Audi before this car btw). I drove it around for about a month or two before it blew the head gasket and I decided it was time to tear it apart. I took the engine and transmission out and my plan was really just tom clean everything up and replace/fix anything that needed some attention along the way. I took everything off the block but left the pistons and crank in it because it didn't look like it needed a rebuild just yet, the cylinder walls looked fine and so did the crank journals (I've also never taken a block apart so I wasn't really comfortable doing that). After the tear down, I cleaned everything up and I recently started putting the engine back together and getting everything ready to go back into the car. Here's a bunch of pics I took along the way:
IMG-1906.JPG

IMG-1907.JPG

IMG-3709.JPG

IMG-3711.JPG

IMG-3716.JPG

IMG-3493.JPG

IMG-3715.JPG

IMG-3713.JPG

IMG-3714.JPG

IMG-3499.JPG

IMG-3500.JPG

IMG-3712.JPG

IMG-3704.JPG

IMG-3705.JPG

IMG-3708.JPG
 

Attachments

See less See more
15
#3 · (Edited by Moderator)
So, along with sharing the build on this forum and telling the story and such, I came here to ask for some advice and look for parts. The other day I was tightening down the cam into the head, starting with bearing caps 2 and 4 as my manual says, and the base where the stud for the bearing cap is started cracking on the right side of the number 3 and 4 studs. Along with that, a whole chunk of my number 4 bearing cap came off. Here are some pics:
Stud for cap #3:
IMG-3700.JPG

Stud for cap #4:
IMG-3698.JPG

Bearing Cap #4:
IMG-3717.JPG

If anyone happens to have a NG cylinder head along with its bearing caps, please let me know.
Regarding the build, I'm planning to pretty much just restore the car and give it the OEM+ kind of look and I want to refurbish these Borbet Type Ts and keep them on the car. Would like to get an S2 bumper and maybe turbo it with the NG head on it as opposed to going with the 20vt swap. But it will be a while before that happens since I'm still in college and don't currently have the funds for such modifications. I've already scored a set of 2bennett coil overs for a really good price so those will be going on the car after I get it back up and running and daily drivable. Also, if anyone has a black b3 dashboard or knows of one currently for sale in decent condition I am looking for one. Let me know what you think of the car/build and feel free to give me any advice and share your thoughts.
 

Attachments

#4 ·
Looks pretty good! Sux about the head! I'd post a WTB = wanted to by add up here in swap meet. You will find everything you need. Most put a DOHC 20v turbo engine from a 91' 200q 20v also known as the 3b engine. Then there's the AAN 20v turbo engine from the 1st s4/s6. Also known as the urs4/urs6. So you'll find the 10v stuff very plentiful. I chose the AAN because of the better timing belt tensioner design and there is no distributor but a cam sensor behind the cam cog pulley. If you knew any of this already sorry to bother you. Where are you at anyway? I'm in south Florida.
 
#5 ·
RennenMsports said:
Looks pretty good! Sux about the head! I'd post a WTB = wanted to by add up here in swap meet. You will find everything you need. Most put a DOHC 20v turbo engine from a 91' 200q 20v also known as the 3b engine. Then there's the AAN 20v turbo engine from the 1st s4/s6. Also known as the urs4/urs6. So you'll find the 10v stuff very plentiful. I chose the AAN because of the better timing belt tensioner design and there is no distributor but a cam sensor behind the cam cog pulley. If you knew any of this already sorry to bother you. Where are you at anyway? I'm in south Florida.
HEY! NO PEER PRESSUR! :lol:

Nice to see you here. I wish I hadn't scrapped the head the cam came from. Overall the car looks pretty nice. As for putting a turbo on an NG, dont bother. The compression on an NG is something like 10.5:1, so way to high for a turbo. You can always drop in a 10vt from a 5000/200 pretty easily. That what I did, and then went kind of crazy... The original plan was to put the engine and MAC11 into my 80q, but I decided to go EFI, along with a ton of other things. It's a deep rabbit hole, so be careful.

Look forward to updates, hopefully someone here can help out with the needed parts.
 
#6 ·
No peer pressure? Me. Nahh :D But he was already talking about replacing the dash. Hahahaha. You have to remove the dash to put a turbo harness in correctly no? Or you can lay the ecu portion of the harness along the floor up to the drivers seat like I did. Unfortunately I don't know much about mechanical injection systems and the 10v.
 
#7 ·
Lol the peer pressure is welcome! I don't know much about all the engine swap options but I have read about how easy it is to swap around the engines from later models and such. Also Im in Chattanooga, TN but I have a question about those swaps. I'm hearing you out about not trying to put a turbo on my 10v Dave and thanks for that info, but how plug and play are the 3B and AAN options? Is it possible to buy just the head and swap it over or would I need to get a full engine. I'm curious because if I could swap the head over and don't need a full engine to do the swap, I could go ahead and do that right now instead of trying to find another NG head. If I'd need the full engine though, that's a no go for me. I've seen partouts and such with the full engines costing $1000 and up, which I simply don't have money to blow on that right now, thanks college. But also what about the 7A 20vt? Ive heard the 7A and NG have the same block so would it be a plug and play swap with a 7A 20vt head and a respective harness? Im just trying to feel out my options here. Im totally fine with just finding an NG head and slapping it on just so I can get it running and driving but if its possible to somehow get a turbo on this baby without spending more than I payed for the car, that'd be pretty spectacular. 130 hp is pretty measly lol.
 
#8 ·
It is possible to put a 7A head on a NG bottom end and create a "ghetto 20vt". The problem is there is a lot more involved than just slapping on the 20v head. Your best option would be to put in a complete engine and harness. You can also put in a 1.8t with some descent upgrades for about the same price as putting in a 3B or AAN. You would need to fabricate or purchase mount arms for that swap though.
 
#9 ·
The 7A doesn't come turbo but there's a kit to turbo it. To go 20v you need to swap over the engine harness which goes through the firewall under the brake booster to the fuse block and over to the passenger side where the computer(s) are. All the 20v's are electronic fuel injection. You would have to remove the dash to do it properly. 10v turbo I'm not sure. If I was in your position I would get an NG head and finish the project and get the car the way you want it. These cars can be money pits. Then I would start collecting parts to either put a 7A in it then turbo that or do it all in one shot with a 3b, AAN Either way you have a great car to start with! I put an AAN in my 91' 80q and it all comes down to the engine harness. I was going to make one but the time and effort into tailoring a turbo harness to that of a b3 then grafting the appropriate connectors onto it seemed excessive at the time. So I sourced a left hand drive S2 ABY harness for my project made things go smoother
 
#10 ·
Alright thanks for the info guys, I think im gonna go with a 3b or AAN depending on what pops up first once I have enough money saved up. I posted up a wtb for a 10v head in the swap meet section on Saturday so now I'm just playing the waiting game, right now there isn't much to do to the car other than mounting the subframe (my precious time in the garage is now over because my dad's project is coming back from the shop in a couple days). I'll keep this updated.
 
#11 ·
Finally found a head! I'm actually on vacation in New Jersey right now and a guy who was located up here about an hour away from where I'm staying messaged me about an 80 he was parting out that had a 10v ng in it. Super coincidential but the head seems to be in great shape, thanks Joel! I'm gonna post some pics soon as well
 
#13 ·
No is a good guy. I'll be heading out to see him soon myself.
 
#14 · (Edited by Moderator)
Lol, it's a small world. It was great meeting you as well man, If I can get this thing running real nice by the summer I was planning on driving back up to go to Atlantic City with some family. If you're up there maybe I'll stop by again. Anyways, I'm back home now and about to clean up this head, here's what it looks like at the moment:
cylinderhead.jpg
 

Attachments

#16 ·
I appreciate the hospitality man, I've got the head as clean as I could get it and just finished removing a broken bolt for the coolant reservoir. As soon as my head bolts get here which should be no later than Monday, I'll put it on the block, change the tranny fluid and tie up a few odds and ends here and there and then the engines goin back in the car. I still don't know if I want to time it myself or take it to a shop to get it timed, but I'll figure that out after I get the engine back in the car.
 
#18 ·
I hear you. I'm kind of worried about doing it myself but at the same time it'd be nice to learn how to do it and also to not have to pay money for the job. I've just never done it before and I know that it is possible to destroy an engine if you do it incorrectly. Ive got an emanual that has some guidelines but the pictures are somewhat blurry and so its hard to see the demonstration. Im gonna do some research and possibly ask around if im not satisfied with my research and well see what happens. I got some parts last night so I'll be swapping the old head with the uncracked one and changing the tranny fluid tonight. Since its been such a prolonged process with the engine out im sure im gonna find a bunch of things I have to do before I can put the engine back in the car. Hopefully I can just remember them all before I put it back in.
 
#19 · (Edited by Moderator)
Time for an update:
Over the past two weeks I've finished reassembling the engine and cleaning remaining parts and working through the things I forgot to do earlier and things I never thought about. I also timed the engine. This week I changed the tranny fluid and mounted the tranny onto the engine, as well as the subframe and I'm currently in the process of getting the engine and trans back in the car. It's halfway in as of last night but my Dad and I ran out of time and today I have absolutely no time to work on it. The method I'm using to put the engine/trans back in requires two people, otherwise I would have had them both in by now. Here are some pics.
10v engine on tranny.jpg

10v going in 1.jpg

10v going in 2.jpg

I'm confident I'll have the engine running and driving by Friday, unless I can't get my friend or my dad to help me tomorrow. I'll post an update once I do get it running and maybe before that as well.

Right now I'm just hoping I don't find some other issue with the coolant once I do get it running. Before I pulled the engine last year, I had some problems with the coolant system or so it seemed. Sometimes after or during driving (only when the car was running though), coolant vapor would come out of the overflow tank enough to where you could see it if the hood was closed, even while driving if you looked closely enough. I may have already stated this previously on this build thread but anyways, one night when I was about to go somewhere, I started up the car and a bunch of white smoke started coming out of the tail pipe. I decided to let it run for a couple minutes to see if it could have just been some water that got into the engine. The white smoke persisted for maybe 5 or 10 minutes until I started hearing some weird noises and I turned it off. I suspected a bad head gasket but when I eventually got to taking the head off I found that there was no coolant in the cylinders, like there normally would be with a failed head gasket.

I'm mentioning this only because I don't know if Ive even solved the main problem I meant to solve in the first place. I don't know if Ive maybe accidentally fixed the problem during this engine refresh process Ive just finished or if Im still gonna have this weird overheating coolant problem when I do get the engine back in. I'll just have to wait and see I guess.

Aside from all that I have a separate thing to say. Just today, I closed a deal on an AAN and a 01E. The buyers gonna pack it up and ship it down this weekend, so if it turns out my 10v runs totally fine then I will still be posting more updates on this thread which will mostly just include cleaning and painting parts, finding parts I'll need for the swap etc etc. I'll also still post updates regarding other tlc my 90 needs (interior, paint and more).
My apologies if this post is unnecessarily large.
 

Attachments

#21 ·
I appreciate it, and I haven't gotten anything other than the AAN and the trans. I need to refresh myself on what I'm gonna need for the swap. Off the top of my head I know I'll need the fuel injection system since the AAN is efi and then the things you said, harness and ecu. At least I wont have to buy a new clutch. Anyways, I'm not exactly in a rush and that's for three reasons:
1. I'm not rich lol
2. I plan on going through the whole engine and refreshing stuff and buying new parts if need be etc etc and this will take time. I understand that there is some aftermarket support for the AAN (especially compared to the NG) so I'd like to figure out how big that market is and explore it a little. Also, after working on the NG I found out that I'm quite fond of the process of going through an engine and fixing it up nice. I might even do a full rebuild if the engine needs it and if I can find a good shop to help me with some of the process (and of course if it won't break the bank) but mainly just if it needs it.
3. The NG is healthy (I think at least, lol) so I won't have that pressure on me to finish up the swap so I can get back in the car, because I'll already be able to drive it. So ill just take my time and do it right. If something catastrophic does happen to the NG though, I'm not gonna spend another penny on it most likely.

Am I missing anything in terms of what I'll need for the swap? If anyone knows a really good thread that outlines the AAN swap that would be a better answer. I'm gonna try and find a good one.
 
#23 ·
Spooky Quattro said:
3. The NG is healthy (I think at least, lol) so I won't have that pressure on me to finish up the swap so I can get back in the car, because I'll already be able to drive it. So ill just take my time and do it right. If something catastrophic does happen to the NG though, I'm not gonna spend another penny on it most likely.

Am I missing anything in terms of what I'll need for the swap? If anyone knows a really good thread that outlines the AAN swap that would be a better answer. I'm gonna try and find a good one.
I'm in the same boat with my CQ. I found the 3B right after I got in running with the 7A. Just taking my time getting it torn down and cleaned up and collecting the parts to complete the swap.

There are lots of project threads on here where they have swapped an AAN into the B3 chassis (coupes and sedans). There are things that can make it easier, like using some 3B parts or sourcing some euro pieces, but nothing is impossible if you can fabricate. I think the biggest challenge with using all AAN stuff is figuring out the radiator and intercooler stuff, since the AAN has the radiator up front.
 
#24 ·
jbrentd said:
Spooky Quattro said:
3. The NG is healthy (I think at least, lol) so I won't have that pressure on me to finish up the swap so I can get back in the car, because I'll already be able to drive it. So ill just take my time and do it right. If something catastrophic does happen to the NG though, I'm not gonna spend another penny on it most likely.

Am I missing anything in terms of what I'll need for the swap? If anyone knows a really good thread that outlines the AAN swap that would be a better answer. I'm gonna try and find a good one.
I'm in the same boat with my CQ. I found the 3B right after I got in running with the 7A. Just taking my time getting it torn down and cleaned up and collecting the parts to complete the swap.

There are lots of project threads on here where they have swapped an AAN into the B3 chassis (coupes and sedans). There are things that can make it easier, like using some 3B parts or sourcing some euro pieces, but nothing is impossible if you can fabricate. I think the biggest challenge with using all AAN stuff is figuring out the radiator and intercooler stuff, since the AAN has the radiator up front.
dont use aan intake unless you want headache.
 
#25 ·
Ok, so unless your block is cracked, the over pressurizing of the coolant tank is a bad head gasket. I had the same problem with my 10vt swap. Mine got to the point of blowing coolant all over the engine bay. Mine never blew smoke from the tail pipe though.

You will want a 7A oil pan for the AAN, which are honestly getting harder to find, and on the expensive side now. As for the 01E swap, you can either modify the 01A linkage, or use a B5S linkage and shift box. As for the rear diff, you are just fine there. Both the B3 and the UrS use a 4.11 final drive. As for the clutch, most people change over to the 7A flywheel and clutch over the AAN's dual mass flywheel and clutch. It's just a simpler setup.
 
#26 ·
jbrentd said:
Spooky Quattro said:
3. The NG is healthy (I think at least, lol) so I won't have that pressure on me to finish up the swap so I can get back in the car, because I'll already be able to drive it. So ill just take my time and do it right. If something catastrophic does happen to the NG though, I'm not gonna spend another penny on it most likely.

Am I missing anything in terms of what I'll need for the swap? If anyone knows a really good thread that outlines the AAN swap that would be a better answer. I'm gonna try and find a good one.
I'm in the same boat with my CQ. I found the 3B right after I got in running with the 7A. Just taking my time getting it torn down and cleaned up and collecting the parts to complete the swap.

There are lots of project threads on here where they have swapped an AAN into the B3 chassis (coupes and sedans). There are things that can make it easier, like using some 3B parts or sourcing some euro pieces, but nothing is impossible if you can fabricate. I think the biggest challenge with using all AAN stuff is figuring out the radiator and intercooler stuff, since the AAN has the radiator up front.
I hear you, Ive just found a couple threads and they confirm what youre saying. I've been reading that 3b manifolds are a good way to go due to their flow and clearance, and also that I may have to cut my bumper in order to fit the radiator and just have it stick out the bottom. Do you have a thread on here of your build?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top