RE: Rings vs. Liners

["Jason Ball" <madmac@domain.elided>]

> My Alfetta '81 suffered  uneven compression, oily cylinders (spark plugs
> turned black after 2 days of use). My mechanic advised new rings but he had
> end putting in new pistons and liner. The old pistons had a thick layer of
> carbon on top but otherwise still looks good. A number of questions come to
> mind.

> 1. Am i duped? Under what conditions do you normally replace pistons?
Normally replace when either pistons or liners have worn "out of round", or
out of spec.  Not too surprising on a motor that was losing compression.

> 2. Any advice on running-in of new liners+piston.
When I rebuilt my 2.5 V6 (re-honed liners, new rings and bearings, rebuilt
heads) I changed oil/ filter every 500 miles for first 2000 miles.  I used
non-detergent oil on recommendation of my alfa shop. Non-detergent oil was
hard to find and some say its use really isn't necessary. (Any one care to
comment?)

I broke my motor in using very light throttle and gradually increasing the
RPM's from 3000rpm @ mile 0 to the redline @ mile 2000.  (I don't have the
kilometer numbers but the shop manual should.)

I started the break in process with a few long drives into the hill country,
making sure to very the RPM's.

I re-torqued the heads @ 500 miles

Make sure fuel injection or carbs are in proper tune.... any raw gas
spilling in the cylinders will upset the ring's "seating".

Enjoy!

Jason Ball
87 Milano Gold
Austin, Texas

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