Forged or Cast Pistons - What's the verdict?

[nealtovsen at yahoo.com (Neal Tovsen)]

I'm in agreement with Ron. If you can get good forged pistons for the price of
cast, go for it! But in most engines, cast is more than adequate.

In my case, I decided I was going all-out. Besides the benefits of being
forged, I took advantage of the custom nature to change rod lengths and piston
shape. But those things may not be of use to your situation.

My block was prepared by BSI Racing and (after telling me that I had completely
wasted my money by going with forged pistons...Stu's nice like that) Stu
strongly advised going with tighter clearances than what JE had spec'd. I had
never heard of this before, and this is the first time I've heard of it since.
I was reluctant to risk all the time and money I'd spent on a last minute
suggestion to do something I'd never heard of, but I decided that Stu probably
builds more race engines in a week than I ever will in my life, so I went with
it.

I haven't regretted that decision yet. Also haven't regretted going forged,
either. The car has survived some stupid fueling tricks that might have screwed
with cast pistons in a forced-induction environment. So there, Stu :P

In fact, you can still hear a tad bit of piston slap when the engine is cold.
The head has been off twice since building the engine (most recently just about
a month ago), and the pistons and bores look great. I sure as heck can't
complain about the power...

I'm also a believer in using the spec rings. Forged pistons aren't exactly
"budget" items. People who buy them aren't interested in cutting corners. If JE
or Wiesco thought that gapless rings were the bomb, they'd use them with all
their pistons.

Neal
1977 Twin Screw Scirocco
235whp, 205wtq
Thanks SNS Tuning & Rotorcharged!

> 
> Don:
> 
> When is the last time you have heard of a cast piston failing in a NA VW
> street engine?  Or any VW
> engine?  Or producing less horsepower than a forged piston in a like-for-like
> comparison?
> 
> My point is that cast pistons are perfectly suited for your intended use.  If
> they are to be found
> cheaper, go for it.  If there are *no* downsides to a forged piston and the
> price is comparable,
> then I'd be comfortable with those too.
> 
> I'd also find a way to use no-gap rings if possible.
> 
> JMO
> 
> Ron
> 
> --- Don Walter <dswalterwi@gmail.com> wrote:
> 
> > So far No one has answered the question but you have managed to evade
> > it.  Please let's talk about the subject.
> > 
> > 
> > On Fri, 8 Oct 2004 11:58:54 -0700 (PDT), Anson Clement
> > <ansonivan@yahoo.com> wrote:
> > > 
> > > Have you put any thought into building an ABF? If you need to buy pistons
> > > anyway you might as well have JE make up a set of ABF spec pieces, pick
> up
> > > an ABA block, and build a real monster.
> > >  
> > > Have a look at Shannon Fenton's site for more info on the motor.
> > >  
> > > I just can't bear the thought of buying new pistons and not going this
> > > route.
> > >  
> > > Anson
> > > 
> > > Don Walter <dswalterwi@gmail.com> wrote:
> > > 
> > > 
> > > Had my 2L 16V block inspected by the machine shop. The cylinder walls
> > > are good and only have .001 taper but my pistons are worn beyond what
> > > spec allows. They are worn .004" and the spec only allows around
> > > .0028"
> > > 
> > > So now comes the choice Forged or Cast (stock). Both are in the same
> > > price range so that is not an issue. And I will most likely be going
> > > with 83mm over sized pistons. Mainly because the machine shop wants
> > > to straighten out the cylinders instead of just putting new stock
> > > sized pistons.
> > > 
> > > Public talk seems to favor WiseCo or JE pistons. Both are forged
> > > type. WiseCo seems to be regarded as a better piston and actually
> > > costs less. I talked to the manufacturer of WiseCo and they reassured
> > > me that the type of problems/noise were eleiminated by newer
> > > technology capabilities. My machinst favored forged pistons as well
> > > and said that the tolerances for a street machine would be tigher that
> > > a race engine which allowed the extra slop for expansion that caused
> > > the noisey slap heard on cold engines.
> > > 
> > > So has anyone actually used forged pistons and what has been your
> > > experience? Any other good suggestions?
> > > 
> > > -- 
> > > Don Walter - Waukesha, WI
> > > 1986 1.8 16V Black Scirocco
> > > 1986 2L 16V Toronado Red Scirocco (under repair)
> > > 1988 1.8 16V Toronado Red Scirocco (sold on 3/29/04)
> > > 1984 1.8 8V Pewter Scirocco (sold years ago)
> > > 1971 Karman Ghia (sold)
> > > 1969 Karman Ghia (sold)
> > > 1969 Beetle (sold)