buying pistons - maybe...

[jdbubb at ix.netcom.com (Dan Bubb)]

This is some data I posted to the list back in April:

<snip>
there are two common alloys used in forged pistons.
2618 is, I believe, the alloy that is not suitable for street use and has given forged pistons their
reputation for piston slap when cold and wearing out rings prematurely. It is a high strength alloy
that has a higher coefficient of thermal expansion than cast material requiring sizeable piston to
wall clearance.
4032 is a more recent alloy. It's not as strong as 2618, but still stronger than cast. It's
coefficient of thermal expansion is also between cast and 2618 so it can have cylinder clearances
approaching that of a cast piston. I've heard some people say this is entirely streetable.
I think the big issue with forged is simply the bigger cylinder clearance and if the manufacturer's
recommended clearance is close to stock, then there is no downside.
<endsnip>
JE Pistons seems to be the most common supplier for our engines.
As far as rods, the stock rods are forged. If you want aftermarket there is Pauter, TT carries a
couple different aftermarket rods, Carrilo......
Maybe just use a set of ARP rod bolts in the stock rods. That should be good for the occasional
burst to 8000 RPM ;^)
Dan

----- Original Message -----
From: "koabi" <saracornelous@mcleodusa.net>
To: "'Scirocco-L@Scirocco.Org'" <scirocco-l@scirocco.org>
Sent: Friday, July 23, 2004 8:16 AM
Subject: buying pistons - maybe...


> Hey all,
>
> I'm going to get my block inspected next week and I want to be prepared
> if I need to get oversized pistons.  I've been looking around for forged
> pistons (and rods, which seem to be impossible to find) for my ABA and
> I've found a few places but I don't know the reputation of any of these
> dealers.  Any leads are appreciated especially if they are priced well.
>
>
> Also, I recall there are two types of metals commonly used in forged
> piston application which have different heat properties.  One has
> properties which may cause some cold start piston slap.  Does anyone
> have experience with that?  I'm just curious if it's as bad as some
> claim it is.  If you know which metals do which I'd appreciate that too!
>
> Off to work,
>
> koabi
>
>
>
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