7A Audi 90 engine - what's the lineage?

So Jolfa's just bought this J-reg Audi 90 Quattro for the princely sum of 255.

This latest photo just looks like a 16v engine:



Ok the oil cap's in the wrong place and the plenum is different, but it's got me looking.

Next thing, quick re-read of the thread and drunkenalan's pointed to a 7A turbo kit.

So this engine looks like a 6A/ACE, and it has an extra cylinder and is called a 7A

Seriously, have VAG got any imagination when it comes to engines, or are they actually all made in Norfolk?

Now that I think about it more, I'm wondering if some 10v 5-potters looked eerily similar to an 8v. Oh dear - are they related too?

Am I on the right lines, or completely making this up?

 

5 pot ?

edit. More gash design by the looks of it, this time with the cam chain at the front, by the looks of it.

 

I was under the impression that the Audi 5 pots were essentially just VAG 4 pots with an extra cylinder.. bore, bore spacing, stroke are shared to some degree between them all.

It's normal procedure.. why redesign something from scratch when you can grow it from an existing, proven format? Less design time, more common parts etc..

As an aside, the 3.6 Audi V8 also shares the same bore, spacing and stroke as the KR, and I think the KR head and one of the V8 heads are interchangable

 

Yep, I know about this one, but didn't realise how widespread it already was across other models!

 

Did you miss the picture of the 10v engine on the first page? []

 

is head design same too? valve angles/sizes etc?

 

The 10v heads are like golf 8v heads but with an extra cylinder. Valves and ports are the same as the golf heads.

The LT 6 and 5 cylinder diesels are similar to the petrol 5 cylinder engines too.

TSRs old catalogue had pics of the 10 and 20v 5 cylinder heads showing how similar they are to the 4 cylinder stuff.

 

what about the 20v turbos? same head design as valver then? always imagined it would have been a bit special compared with other stuff

 

The KR and ADU (20V 5 cyl Turbo from the RS2) share the same valves, followers and timing chain.. it's possible that the valve angles and port dimensions could be different, but I doubt it.

IIRC the S2 lump is about 230bhp out of the box - around 100bhp/litre and not a huge step up from the KR's naturally aspirated 77bhp/litre. Quite easy to achieve with forced induction and the same port geometry, I'd imagine.

Yay for parts bin engineering

 

the five pot stuff is just that chris a 4 pot with an extra cylinder, port spacing are the sames thats why the cut s2 manifold is popular for 16v turbo setups, the rods are the same length 144m cranks have the same stroke. the WR engine has a smaller bore making it a 2144cc rather than the later 2226cc which is 81mm.

I have never seen a 8v turbo setup using audi parts, altho im tempted to have a go !

 

very different!

EDIT Misread the post, actually they are very similar!

 

Comparing like for like. ie 2.0L catalysed engines:

ABF 16V = 148 bhp @ 6000 & 130 lbft @ 4600 - rev limit approx 6400

NM 20V = 160 bhp @ 5800 & 140 lbft @ 4500 - rev limit approx 7400

You need to also consider this catalysed power versus the then Motorsport Super Car ( suposedly).

The M3 E30 gave 84 bhp per litre, with 'Motorsport' writ large on the engine!

I don't think the Audi 20Vs, 2.0 and 2.3, were too bad with 80 bhp/l!

 

20V blocks are of a lighter construction, with external stiffening ribs.

Crank nose oil pumps. Internal water pump. External knock-in breather, a la VW small blocks. No ancilliary/balancer shaft.

 

Audi 90 20v. Beautifully quiet to 7800 rpm!

[YOUTUBE]UKLtD-Nvc2w[/YOUTUBE]

http://www.youtube.com/watch?v=UKLtD-Nvc2w

 

So what's the timeline of the Audi 90 20v n/a vs 20v turbo engines? Created at similar times, or completely different starting points?

 

Pretty sure that the S1 20V came first. 20V n/as use the same distributor, at the back of the head, as the S1. Pretty sure that the other turbo 20Vs use a trigger wheel on the front of the camshaft. Don't know much about the turbos other than S1s.

 

The lineage is why you can take S2 manifolds, chop off a runner and bolt it to your 16v for an easy turbo conversion .

Con rods in the KR are supposed to be the same part no as the s2 too?

Gurds

 

Not necessarily easy.

 

All making sense now. This is why I've heard of S2 conrods being used in 4 potters?

So all these engines have got 144mm rods in them?

 

Also why KR's had sodium filled exhaust valves. You didn't really think an NA engine needed such high temp exhaust valves?

Tshirt2k: well a little easier than a full custom manifold job.

Gurds