Anyone running the Arias pistons from O'Connor's?

[Scott Walters]

Hi all,
I have some new pistons care of O'Connor's http://honda600shop.com
They're Arias customs: http://ariaspistons.com
I had the cylinders rebored, but one thing I missed is that Arias pistons are
forged, not cast, and forged pistons specify more cylinder to piston clearance.
Anyone on here running pistons from O'Connor's?
What did you do in terms of cylinder to piston clearance?
Anyone running factory spec (0.0012") clearance with those?
I ordered 1mm oversized (per previous discussion) and had the cylinders
rebored to match. I missed this though:
http://ariaspistons.com/pdf/motorcycle-installation.pdf
Arias recommends 0.003" clearance versus Honda's specified 0.0012".
When I had it rebored, I gave the machine shop a copy of the factory
specs page from the service manual so I'm guessing that it's to Honda's
specs, not Arias'.
I found this explanation of the problem here, which claims that forged
pistons tend to distort, especially if not carefully broken in:
http://www.hardcoresledder.com/forums/2 ... -cast.html
Maybe suggesting that I'm okay is this FAQ by another forged piston
maker, which says that 0.001" min is fine for 3.000-3.624" bore, and
larger bores require more clearance:
http://www.probeindustries.com/Articles.asp?ID=161
75mm (74 + 1) works out to about 2.9".
The pistons are installed in the cylinders and I'm in the process of
bolting things down and *then* I decided to start researching more and
doubling checking things.
Insights and experiences welcome!
Thanks,
-scott

[Bill]

So, what does Mike say?

[Scott Walters]

I'm primarily curious if people have generally away with running
0.0012" on these. Failing that, I am interested in what's recommended
and you're right that I could ask Mike about that.
Thanks,
-scott
On 5/9/14, 'Bill' billmyong@... [2cylinderhondas]
wrote:

> So, what does Mike say?
> _____
> From:
2cylinderhondas@yahoogroups.com
> [mailto:
2cylinderhondas@yahoogroups.com
]
> Sent: Friday, May 09, 2014 4:41 PM
> To:
2cylinderhondas@yahoogroups.com
> Subject: [2cylinderhondas] Anyone running the Arias pistons from
> O'Connor's?
> Hi all,
> I have some new pistons care of O'Connor's
http://honda600shop.com
> They're Arias customs:
http://ariaspistons.com
> I had the cylinders rebored, but one thing I missed is that Arias pistons
> are
> forged, not cast, and forged pistons specify more cylinder to piston
> clearance.
> Anyone on here running pistons from O'Connor's?
> What did you do in terms of cylinder to piston clearance?
> Anyone running factory spec (0.0012") clearance with those?
> I ordered 1mm oversized (per previous discussion) and had the cylinders
> rebored to match. I missed this though:
http://ariaspistons.com/pdf/motorcycle-installation.pdf
> Arias recommends 0.003" clearance versus Honda's specified 0.0012".
> When I had it rebored, I gave the machine shop a copy of the factory
> specs page from the service manual so I'm guessing that it's to Honda's
> specs, not Arias'.
> I found this explanation of the problem here, which claims that forged
> pistons tend to distort, especially if not carefully broken in:
http://www.hardcoresledder.com/forums/2 ... le-piston-
> info-forged-vs-cast.html
> Maybe suggesting that I'm okay is this FAQ by another forged piston
> maker, which says that 0.001" min is fine for 3.000-3.624" bore, and
> larger bores require more clearance:
http://www.probeindustries.com/Articles.asp?ID=161
> 75mm (74 + 1) works out to about 2.9".
> The pistons are installed in the cylinders and I'm in the process of
> bolting things down and *then* I decided to start researching more and
> doubling checking things.
> Insights and experiences welcome!
> Thanks,
> -scott

[Bill]

Hi Scott;
    I would check the ring gap.  If the pistons are already in the cylinders this will meaning pulling them out and removing the rings unless the shop that did the work gave you specs.  Going back and redoing the bore will mean new rings.