compression ratio? aaz 11mm pump holset turbo?

[mk3pete]

ok so im building my aaz up from scratch! it was originally going to be a basic refresh but turns out my bores were flogged and had a bent rod.
il be running 1mm oversize nural pistons
roston h beams
Dieselmeken 11mm pump
holset he200wg
arp everything
ported head
hoping to make 30 to 35 psi

what would a recommended cr be? i know il be lowering from standard but how much lower?

[theman53]

You will be fine at the stock levels for aaz, I think that was around 22:1 for that engine. Cutting the dish out in the piston, porting the prechamber, or undercut valves are the only way I would take compression down.

[libbydiesel]

That build will not last long unless you have a crank girdle.  Otherwise you will break a main.

[vanbcguy]

I wonder what it is about the AAZ blocks that seems to make them so much more prone to breaking mains. Seen more than a few now. The TDI blocks don't seem to have as much of an issue despite being virtually the same.

[theman53]

65mm main bolts came in some aaz, the others had 80mm like the tdi. I would guess that is a part of it.

[mk3pete]

I was thinking about a girdle but wasnt sure if I need longer bolts to torque it down? If so anyone know where to order. Or any other requirements I need to run one.
Roston do a girdle and that's where im buying most of my parts.
Might have to throw him an email.

[mk3pete]

Maybe someone might be kind enough to release a drawing of one so I can machine it up myself?
Dads got a milling machine at home so il get some 6 mm plate! Bright steel would be best as theres no mill scale on it to worry about cleaning up.

[Gizmoman]

Sandblasting will remove scale as well  ; - )

Not sure what you goals are but make sure the rest of the vehicle is up to the increase if your goal is reliability.

[mk3pete]

Im already running o2a and bigger clutch also g60 brakes, I have another built box on my vr6 im thinking about swapping into the td 3.94 rp peloquin and tdi 5th.