31 Jul
2001
31 Jul
'01
4:28 a.m.
At 09:48 PM 7/30/01 -0700, Fred wrote:
GM saved a lot of money by making an aluminum block
with a friction
reducing coating (Teflon??). It worked well for a limited time.
Actually they didn't add a coating to the cylinder wall. What they did
was to make the engine out of high silicon aluminium, then they chemically
etched away some the aluminium in the cylinders to leave high-silicon
content for the pistons to ride on. This was GM attempt to get away from
having to add steel cylinder sleeves to an otherwise aluminium engine
block. (You CAN NOT run aluminium against aluminium.) Needless to say this
design was highly dependent on high quality oil, frequent oil changes and a
GOOD oiling system. Unfortunately the oil pump and oil system were a joke
and Americans aren't known for frequent car maintainance.
Joe