[V8] Spectral analysis V8 ABH and PT blocks

[Bastian Preindl]

Dear list,

as a follow-up on our discussion two years ago regarding the "real" 
cylinder coating and/or block alloy in the Audi V8 engines PT (3,6) and 
ABH (4,2) I can now provide you with some new details and - finally - 
facts. As you may know there were always rumours going on that the ABH 
blocks may be NiKaSil coated which shall explain the large oil 
consumption of some 4,2 V8s, even though it didn't make a lot of sense. 
We now have the results from the spectral analysis of both the ABH and 
the PT blocks and they are as follows:

1) PT and ABH are made of completely identical alloys
2) Both blocks are AlSiCu alloys
3) Both blocks have etched cylinder walls
4) The common name of the alloy is G-AlSi12 and is a "standard material" 
for strong requirements on solidity and strength - a typical alloy for 
combustion engines
5) Additionally vestiges of iron ( Fe, approx 0,67%) have been detected, 
supporting the solidity as stated as requirement in 4)

For most of you all this is probably no surprise - but back in Europe 
this has busted a myth which was spread around since ages and caused 
numerous V8 owners to sell the car as they thought its engine is 
irrepealable broken (this includes myself). Still, the question is given 
why some ABH need more oil than fuel (>3 liters is not exceptional) even 
after the heads have been overhauled but it is at least proven that it's 
not cause Audi has used NiKaSil for some strange reason on this and only 
this engine...

Credits to Manfred M. from Augsburg for his efforts!

Best regards

Bastian

PS.: I've sent this also to the 200Q list as this might interest future 
and past V8 owners as well and the V8 is usually also a lively topic in 
the 200Q circles