Standard for allowed overbore is 0.042" last I looked.
On the other hand Bob, if you are trying to be fast and cheap, TRF has
some +0.010" racing pistons on sale at the moment.
iii
> -----Original Message-----
> From: R. Kastner [mailto:kaskas@earthlink.net]
> Sent: Friday, January 07, 2000 12:07 PM
> To: Ted Schumacher; Bob Lang
> Cc: fot@autox.team.net
> Subject: Re: Piston Question
>
>
> I always made more power with cast pistons ( good quality)
> for the reason
> that you could run a closer bore clearance and generally they
> were quite a
> bit lighter. Problems only when the ignition timing was
> neglected ( checked
> carefully) But then, this was in the days of old when they
> had just invented
> dirt. By the way most regulations allowed a .040" overbore .
> ----- Original Message -----
> From: Ted Schumacher <tedtsimx@q1.net>
> To: Bob Lang <LANG@isis.mit.edu>
> Cc: <fot@autox.team.net>
> Sent: Thursday, January 06, 2000 4:34 PM
> Subject: Re: Piston Question
>
>
> > Bob Lang wrote:
> > >
> > > Hi,
> > >
> > > I'm getting ready to start building my next motor. This would be
> > > semi-ironic in that I actually haven't started the
> primary motor yet...
> > > but I never do things in the general linear fashion
> anyway.... so...
> > >
> > > This one will be around 12.5:1 compression ratio. I've
> got the block at
> > > the shoppe, and there's a slight taper to the bore - so a
> re-bore seems
> to
> > > be in order. Seeing that I'm boring anyway - I might as
> well "open it
> up"
> > > to a .030 overbore or whatever.
> > >
> > > I'm looking for the collective list wisdom regarding
> whether I should
> use
> > > cast or forged pistons for this job. I'm also seeking advice about
> > > ceramic coating etc.
> > >
> > > If I need forged pistons, I'll also need a source of new income...
> unless
> > > someone can elighten me on an inexpesive source of forged
> pistons. I'd
> > > also like to hear any experience with hyper-utectic
> (sp??) pistons, as
> > > they are sort of in-between cast and forged, cost wise as
> near as I can
> > > figure from reading my books on the topic.
> > >
> > > Thanks in advance.
> > > rml
> >
> >
> --------------------------------------------------------------
> ------------
> -----
> > > Bob Lang Room N42-140Q | This
> space for rent.
> > > Consultant MIT Computer Services |
> > > Voice: (617)253-7438 FAX: (617)258-9535 |
> >
> >
> --------------------------------------------------------------
> ------------
> -----
> > bob, forged are not that expensive. we supply custom built forged at
> > $120 a piston plus rings. these are made to your specs or
> a standard
> > design. since 12.5 is fairly low compression for a race
> engine, probably
> > sticking with a flat top design is fine. ted
> > --
> > Ted Schumacher
> > TS Imported Automotive
> > 404 Basinger Rd.
> > Pandora, Ohio, USA 45877
> > Ph. 800/543-6648 USA/Canada FAX 419/384-3272 24 hour
> > Ph. 419/384-3022 - tech./general information
> > Web page http://www.tsimportedautomotive.com
> > New-Used-Rebuilt-NOS-Performance British car parts.
> > 200 - 300 parts cars in our British-only salvage yard.
> >
>
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