im trying to figure out if the 20V inline 5 in the 90' 91' year model's of the 90 quattro is the same engine as the AAN or the 20V inline 5 that is in the S4 or S6. if anyone knows please help me out here.

 

if you are talking US spec, the 90/91 CQ and 90q20v used the 7A. normally aspir. 2.3L 20v. related to the 3B/AAN/ABY, but definately not the same. you can get the IM, EM, turbo, ECU, cams, and other misc pieces and convert the 7A to any of those engine specs though...

europe got the 2.0L 20v (NM), 2.3L 20v (7A), and the 2.2L 20vt (3B then replaced by the ABY) in the B series chassis.

 

what is the engine that is in the s4/s6's. in about 6 months i'm planning on starting my RS2 project and i need to know what engine i need, or what car i need to buy. i have a 94' 90s right now, but its not quattro and its a V6 and an automatic so im planning on getting rid of it to get a 5 spd and a quattro. but i need to know where i can get the AAN engine, or the closest thing to it so that i can get the RS2 engine kit for it.

 

AAN only came in ur-s4 and s6. closest thing to it is 3B from '91 200tq

 

Don't even think about putting an AAN in your FWD Audi

 

You said you can convert between them, meaning I assume that they have the same (or very similar) engine blocks. I always figured they were pretty different, since I'd never heard about converting a 20v 7A to a turbo AAN or equivalent. That's good to know, although it must be a major PITA (or more expensive than buying a whole AAN) to do so, since I haven't seen anybody that's done that yet . . .

 

the AAN would be the closest thing to the ADU, at least for the US market. however, you will want some S2 (ABY) and RS2 (ADU) parts to make it go in easier. things like various ancillary brackets, front x-member, etc to facilitate both the IC as well as the AC system. going with S2 parts for these may be cheaper than getting the RS2 bits, but then again, they may be the same parts...

definately get a better base car to start with (sounds like you are going for a different B3 or B4 quattro), then start looking for a donor car. if you want to get the 3B (most likely cheaper in the get go), then look for the '91 200q. otherwise, any S4 or S6 will do. one thing to consider is the drivetrain. the S2 and RS2 both used different axles (bigger) than the CQ or B4q. also, the better tranny would be the 01E from the S4/6.

the big differences between the 3B and the AAN/ABY/ADU is their ingnition systems. the 3B is a system similar to the CQ (single coil + disttributor) vs the Axx Coil-On style, where the coil packs are over each spark plug. you can update the 3B to this style, but at that point, why get a 3B (unless thats all you can find).

definately talk to brandon hull, tom vandervoort, or jimmy pribble (sp?), or various other people that have done (or are doing) the conversion.

 

bore spacing is the same (bores different by 1.5mm), the head of the 7A has a couple fewer oil passages (or are they water? however, the NM and 3B use the same head gasket, and the 7A and NM use the same head but different cams), and obviously the cams and CR is different. put a set of 3B or AAN/ABY cams in the head, and drop the CR, and you'll be set to bolt up the 20vt externals.

a few people have done it. TAP did it (but they uh, had problems), Mark Nelson (Sierra Motorsports) did it to his CQ several years ago, and Bernie Benz is working on a project that will not have to swap out pistons to drop the CR (doing it with the cams).

it's actually about the same cost to do either, i think... custom JE pistons with a 8.5:1 CR are like $150/ea, and you'll want different rods to cope with the higher stresses (the 3B pn ends in 401A, the 7A ends in 401, so difference is???). cams are, well, depends on where you get them. you'd have to get the IM, EM, turbo, vac stuff, etc, as well as the ECU and harness from a 3B, since the 7A's hitachi doesn't know what the heck to do with boost.

so, depending on what you want to do with the car, it may be more cost effective to start with a 7A long block, since the bits you have to replace, you'd do so anyway to break the 300hp mark with a 3B or AAN. also depends on how cheap you can get a 20vt complete engine for...

 

Since I don't already have 7A, I think I'd just look for a complete turbo anyway . . thanks though!

 

Re: The UrS-cars had the ANN 20vt...some of the '91 200s came with the 3B 20vt....the 20v N/A is 7A