Weird crankshaft in my AAN engine

[AANton]

Thank you very much!

I'm now in a search for a forged crankshaft. Damn shame, but what can I do.

[K Simmonds]

Here's my NG block and crank, the NG has an 82.4mm bore and my 3B is 81mm. So they certainly used bigger pistons in the NG/NF. No part No on the crank, just the few cast numbers in the photo's.



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[K Simmonds]

Thank you very much and I would really appreciate your measurements and photos.

Yes, I know, NG is a rather common I5 engine, I have it in my Audi 90 B3 quattro and I surely hope it is forged and that it fits in my AAN engine.

Waiting for your reply.

I'll get you some measurements and photo's tomorrow as I'm going to be in the workshop trying to find a couple of obscure parts for other members, that block is hidden behind some other heavy stuff under my workbench so will take a bit of getting to.

I had to spend most of this afternoon moving firewood into the house otherwise I'd be cold this evening.

Yep the NG is a really common motor and the NF as found in C4's is pretty much identical, I didn't know that some NG cranks were cast as 'rxl' points out, I'm pretty sure the one in my old block that came from a 1992 Coupe is forged.

[rxl]

not all ng2 cranks are forged. i used cast one and its ok for a bit more power

[AANton]

How precise was your 6mm measurement? Could be an NM crank which has a stroke of 77.4mm vs 86.4mm of the AAN?

Very precise. You can see it on the photo.

The only logical answer is that it is from a NM engine.

For me, that is the only thing that makes sense.

I can’t see any other option.

[AANton]

I'm 99% sure the NG is also forged, I have a block and crank under my workbench without a sump on that I can check out for you, I'll try and find time this afternoon to have a look and take some measurements and photo's.

If it is the same then NG cranks are very common, I sold the bare block and crank for £150 which I was pleased with. The guy who purchased it is using it as the base for a 3B S2 engine build and knows what he's doing so I'm pretty sure the crank would be forged.

If not then a good 2226 crank is probably worth between 100-300 Euro's, I guess it depends on which country it's in.

Thank you very much and I would really appreciate your measurements and photos.

Yes, I know, NG is a rather common I5 engine, I have it in my Audi 90 B3 quattro and I surely hope it is forged and that it fits in my AAN engine.

Waiting for your reply.

[AndyP]

How precise was your 6mm measurement? Could be an NM crank which has a stroke of 77.4mm vs 86.4mm of the AAN?

[K Simmonds]

I'm 99% sure the NG is also forged, I have a block and crank under my workbench without a sump on that I can check out for you, I'll try and find time this afternoon to have a look and take some measurements and photo's.

If it is the same then NG cranks are very common, I sold the bare block and crank for £150 which I was pleased with. The guy who purchased it is using it as the base for a 3B S2 engine build and knows what he's doing so I'm pretty sure the crank would be forged.

If not then a good 2226 crank is probably worth between 100-300 Euro's, I guess it depends on which country it's in.

[AANton]

Yes, as far as I'm aware all the 2226 CC engines use the same forged crank.

It's possible the one from a 2301 CC 10 valve NG engine may also be the same as they used the same block casting as the 2226 engines, not sure if they used a different stroke or larger diameter pistons to gain the extra 75cc.

I can check the bore diameters as I have both blocks/cranks in my workshop, they're both already sold however.

I’m gonna need a forged one, but I would appreciate if you could measure this just to re-check some things.

Anyone knows what can I expect price wise, regarding forged crankshaft for AAN?

[AANton]

if your piston is 6mm under the top of the block at tdc i would ask some questions how it ran.
anyway the crankshafts are not the same in all 5 inline engines so there are some details that you want to pay antention. not all 7a, rr cranks are forged.
if your not planing running crazy power get a crank from ng2 engine its not forged but cost alomoast nothing.

It ran. I can post a video, I drove it. It lacked power, but it ran.

I’m gonna go for bigger power in the long run, I’ve already bought forged rods, so cast crank is a big no for me, but don’t know how can I know which one is forged, except visually, since they all have the same number.

And when you say that they are not the same, do you mean on forged/cast or something more?

[K Simmonds]

Yes, as far as I'm aware all the 2226 CC engines use the same forged crank.

It's possible the one from a 2301 CC 10 valve NG engine may also be the same as they used the same block casting as the 2226 engines, not sure if they used a different stroke or larger diameter pistons to gain the extra 75cc.

I can check the bore diameters as I have both blocks/cranks in my workshop, they're both already sold however.

[rxl]

if your piston is 6mm under the top of the block at tdc i would ask some questions how it ran.
anyway the crankshafts are not the same in all 5 inline engines so there are some details that you want to pay antention. not all 7a, rr cranks are forged.
if your not planing running crazy power get a crank from ng2 engine its not forged but cost alomoast nothing.

[AANton]

Anyone here has 7A, RR, 3B, ABY, AAN or ADU crank, forged (I guess all are?) for sale?

EU only.

Drop me a message.

[AANton]

did you run this engine or buy it used ?

I bough the car. I drove it a little. It worked, but had low compression.

[AANton]

A 2.0 NM crank would explain the shorter stroke...

It must seriously lower the compression being 6mm off deck height so unless you want a much lower compression ratio for some reason then I'd want the correct crankshaft.

7A, RR, 3B, ABY, AAN and ADU all use the same crank.

Yes, compression was low, around 4, but the compression rings were really bad too.

So, any of those engine codes can do? Are they all forged?

Because I ran into info that basically any crankshaft from I5 would work.