On Tue, 30 Mar 2010 10:22:34 -0700, Tim Wescott
wrote:

Fred the Red Shirt wrote:
On Mar 17, 2:32 am, Tim Wescott wrote:
...

With some pretty fancy metallurgy you can use an aluminum cylinder wall.
It's how the Chevy Vega was done, and it worked great -- except when
it didn't.
...

Which I thought was all of the time. I never heard of a Vega engine
that
lasted past 50,000 miles, or Vega body that wasn't rust perforated
after it's
second winter in the rust belt.

Had it been built to last the Vega would have been a great little
car.

There's an interesting Wikipedia article on the origins of the Chevy
Vega. Apparently it was designed by GM corporate engineering, and
shoved down Chevy's throat. Chevy wasn't allowed to make _any_
engineering changes, they were very grudging about building the thing,
and that was a huge part of the problem.

Apparently the wear point on the Vega engine wasn't the cylinder walls
at all -- it was the valve guides*. But the oil leakage** got blamed on
the cylinder walls because who could believe in an aluminum cylinder
bore? For it's size it's certainly a damn strong engine.


Totally not true. The only fix for the extreme oil burning was to
sleeve the block - and that is not required for valve guide problems.
When they were running well they WERE very torquy engines, giving the
impression they were a lot bigger and "stronger" than they were.


* Which were as new and innovative as the rest of the engine, just
wrong. If you're going to make something that's new and innovative,
identify the parts that _need_ to be new and innovative, and do the
_rest_ of the thing with old reliable technology. Then when that works,
go back and innovatize the rest of the thing, one system element at a time.

** "Fill er up and check the gas while you're at it!"