Re: Cast pistons VS. Cast Pistons LOL!!

[Tom Jennings <tomj@xxxxxxx>]

On Tue, 2004-09-21 at 21:19, biljoh@xxxxxxxxxxxx wrote:

>    If the stock pistons lasted 35 years why wouldnt an equal or
> slightly better set last just as long? 

If they were of equal-or-better, then true, but there's enough anecdotal
evidence that maybe the Badgers aren't.

> The stock pistons are cast aluminum, the badgers are cast aluminum
> with the addition of the reinforced skirts. I used to rev with the
> stock OE pistons to 55-5800 RPM from 1st to second pretty much on a
> daily basis from rest. I still havent heard why the cast pistons that
> I have that are going to replace the cast pistons that I "had" are
> only going to last a year under the same conditions? 

It might be that back-in-the-day that the quality of the casting was
more consistent -- mix, thickness, porosity, cooling rate, cooling
evenness, alloy used, etc. Manufacturing is a tricky process, there's
lots of room for variation; really high quality manu's more readily
throw parts back into the scrap bin if something is out of spec; lower
cost manu's like Badger might accept them.

There's a calculus for this, but we don't have access to it. When
there's just one of you, and you're making one motor, paying out of
pocket, saving $500 cast vs. forged pistons probably isn't worth it.
YMMV.

>  What about the people that use badgers and don't have problems with
> high performance durability?  

They may have got a really solid set from badger that day. The next day,
pinholes.

Pinholes in castings are caused by bubbles and pockets of gas, implying
poor quality control, when the part is machined the top half of the
bubble is removed leaving a pit. You have to wonder if there aren't
other bubbles in the metal, say in the skirts, or near the top ring
groove...

They're "good enough" parts for "good enough" rebuilds, eg. a repair
shop does a rebuild on an older car, it lasts long enough to be way out
of the warranty of the repair shop. It can even be the most honest shop
in the world; if an engine fails years later, how would the shop know?