[V8] Alusil/Nikasil oil burner? WAS:Engine rebuild options
Etdmail at cs.com
Etdmail at cs.com
Fri Aug 29 10:32:41 PDT 2008
Hi all ..
On some of the early hi-mile 928's etc.
It was not the bore or the rings that were usually
the cause of high oil consumption - it was the oil rig
groves in the pistons that got worn out of tolerance
over time ..
Date: Wed, 27 Aug 2008 21:13:51 -0500
From: "Sean cole" <v8coupe at gmail.com>
Subject: Re: [V8] Rebuilding options
To: v8 at audifans.com
Ladies and Gentlemen
Here is the deal Audi used CHEAP rings in the V8 engines. Here is one of
the main issues with Alumisil blocks. Silicon bores are abrasive, think
about it silicon is tougher then iron and wears stuff out. The stock rings
to the best of my knowledge are plasma coated Iron rings (CHEAP) the plasma
coating is required to prevent premature wear. What happens in abused and
high mileage engines is this coating wears and you start getting excessive
ring wear. The only solution to this is new rings. My suggestion is
chromoly rings with a low friction coating if you would like.
Here is a picture of my 4.2L ABH code engine as the PO rebuild it. (if your
reading this Pasha thank you for the fine work ;-) )
The rings are available and out there. Heads are also a known issue on the
newer and older VAG motors. I plan to rebuild a 4.2L ABZ code engine with
new rings, new guides, new seals, etc. The smoking issues is a know issue
and is not limited to Audi engines. There are other alumisil engines that
have the same problem. Also honing this is an option find any one that does
944/968/928 Porsche stuff same exact technology (trust me BTDT) most should
be able to help you out.
As for torque specs I can't help you there at the moment, but I'd guess use
whatever a 2.7tt uses for the rod bolts, the mains I can't help.
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