[urq] Bottom end rebuilt

Louis-Alain Richard laraa at sympatico.ca
Wed Apr 9 20:49:21 PDT 2008

Hi everyone,

Since the explosion of my WX in January, I finally found and got delivered a
replacement engine, thanks to the Toronto Audi mob. 

Now, before dropping it in the car, we, Geraint and I, opened it and since
there was a bit of wear, we decided to replace the crank and rod bearings,
as well as the piston rings. Everything would remain standard, unless the
machine shop finds that the bores are too oval. I doubt so.

The pistons are still nice except that 2 had top rings stuck in grime,
probably from the bad turbo that made the engine drink oil a bit. A good
turbo was found and should be on my doorstep any day soon. 

The rod and main bearings are worn down to the copper, but the crank is
still mirror-polished. The head as no cracks, it was replaced recently and
it has the long injector inserts. I had the exhaust manifold broken studs
removed professionally, and it's clean and ready for install. The exhaust
manifold is straight as an arrow with only a very small crack, much smaller
than on mine.

Now, I have still a few questions before the rebuilt :

1 - Why Clevite/Mahle, in their catalogue, suggest only 1 part number, a 1st
undersize main bearing set ? Their only suggestion is MS1434P-.25mm, there
is no Standard or 0.50mm set. Other brands, namely Federal-Mogul and Audi,
propose std, 1st and second undersizes.  

2 - The old setup of the crank is 5 main bearings and a set of thrust
washers. Both Clevite and F-M propose bearings with the thrust washer
integrated into the #4 main bearing. Clevite says it would work with either
setup. Is this true ?

3- Is the oil pump a device that usually need replacement, as on the
'murican engines ? Is it replaceable in situ with the engine in the car if I
discover later that I should have replaced it now ?

4- WRT the rings, I have difficulties finding the correct set of 5, but
there is plenty of 4 cylinder sets (VW engines) that are identical
dimensionally. I may be able to buy two of these for less than the price of
one set of 5 ! Anyone needs 3 rings set for 3 pistons ?

5- Still in the Clevite/Mahle catalogue, a PDF downloadable, they propose 2
different part numbers for the rod bearings. They state that 1983 is one
style, and 1984-1985 is another. ETKA shows only one. I guess there is a
typo in the catalogue, there is other evidence of that elsewhere. The
difference is minimal, as in 1.8087/1.8094 for the 1983 and 1.8802/1.8810
for the 1984-85. Anyone has the precise measure before I order, just to
confirm ?

6- Should I loctite the exhaust manifold studs in the head ?

7- Was the oil pan painted black in the inside ? I cleaned it very well, but
there is still a black coating on the sides that looks like black paint.

That's all I can think of now, I'm gone reading the Bentley to see if there
is useful information in there...:_)

1983 Quattro, slowly resurrecting 

PS: Now that I have the engine open and dismantled, the only thing in this
car on which I didn't work is the transmission and the rear diff... I guess
I'll have to open them one day just to be able to say that no part of this
car was left untouched by me ! 

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