Compression

[Jcarrick]

Hey guys,
What kind of compression should i be seeing in an AAN?

[Flat on my back]

.

9-13 bar, 7 bar lower limit, 3 bar max. difference between cylinders.

Hth

[Jcarrick]

So would about 10.3bar in every cylinder, even, be good??

[Flat on my back]

.

Yep, how many k's on the engine.

[Jcarrick]

180000 miles, not kilometers. Do you think i have anything to worry about?

[Flat on my back]

.

It's just showing it's age...the bores on these beasts wear out very slowly and i mean very slowly.

As long as the pressure is about the same over all pots nothing to worry about, unless you're thinking of starting on an engine tune and bigger turbo.

[Jcarrick]

The pressure is perfectly equal in each pot. I was hoping to do a new turbo, injectors, etc. and get between 350-375 whp without doing anything to the internals yet.

After that i will put some H-Beam rods in it and new rings and bearings

[Flat on my back]

.

Personally i'd do it the other way round...then you know the internals are up to scratch and good for the later work...cos that will just escalate to madness...

[UrS4boy]

Compression Test Requirements as per section C15-7 of the Bentley

Hey guys,
What kind of compression should i be seeing in an AAN?

Compression Pressures:

Specified Value: 9.0 to 13.0 Bar (131 to 189 psi) (ED: 1 BAR = about 14.5 psig)

Wear Limit: 7.0 Bar (102 psi)

Maximum permissible pressure difference between individual cylinders: 3.0 Bar (44 psi)

The above is in the AAN workshop manual pdf (in Bar only) that you can download. See link: Link to AAN workshop manual download:

http://s2-audi.co.uk/workshop/aan/aan.pdf

[caterpillar]

http://s2-audi.co.uk/workshop/aan/aan.pdf VERY nice pdf.... !!!!! thanks