[AMC-list] 360 pistons

[Nick ALFANO <71amx@xxxxxxxxxxxxx>]

Hi Bruce,

The D shaped dish is similar to my pistons and will make them more efficient than some of the stock designs.  They will most likely charge more when all is said and done to do something different than a standard dish.  Typically flat tops are the cheapest, then standard dish, with dome and custom dish being the most expensive designs.
 
The stock 5/64 rings are readily available for all of the AMC gen II and III engine bores sizes so I am not sure I would go to the 1/16 rings for a street engine.  They are better suited for higher rpm race engines where you are concerned with ring flutter and tension.  The 5/64 rings will have better heat transfer to the water jacket and will wear better in the long run for engine that will see more than just Sunday driving to the local show.  Unless you plan on constantly spinning 7000 rpm and are looking to build an engine with really fine tolerances to get the most hp possible (kind of defeats the purpose of a lower cost engine build), the thinner ring won't be a benefit over the stock size.  Even at higher rpm, there are design ways when making a piston to get thicker rings to work as well as thinner rings.  I build engines spinning 7 grand with the 5/64 and they run great.  Cars in the 11s on pump gas that can drive anywhere with
 no power adders.  

As for the piston specs, the mfg should be asking for things like bore, stroke, rod length, deck height, head chamber and desired compression..... instead of going off of a old piston blank.  If you tell them you want a compression ratio of X at a specific spec below stock 9.208,  it shouldn't matter how far below that is.  The dish volume and pin height will decide that.  This is not the same as saying I want a piston made with a deck height of 9.198 to be 9:1.  With the spec you have listed below, a stock bore 360 should have a compression height of 1.603 with about a 27.2 effective volume to get 9.0:1 with a common style head gasket.  

You might want to also ask them about pin diameter.  It is hard the find the exact pin size for the AMC pin to run as the stock pressed fit of our rods.  Most often you are either forced to go with a Chevy .927 pin or if they have a .930 available, it is still typically right at .930 which is just slightly under the proper pressed spec forcing you to bush your rods.
 
Let me know if I can help.  Diamond said they don't make any hyper pistons to even be able to make them for me and I didn't go looking anywhere else since I knew you were looking into it.  
 
Thanks,
 
Nick

 Alfano Performance
4849-76 st.
Kenosha, WI. 53142
262-308-1302
262-942-8271 after 6pm central and weekends 


Message: 2
Date: Tue, 2 Mar 2010 17:15:59 -0500
From: "Bruce Hevner" <scramblr@xxxxxxxxxxx>
To: <amc-list@xxxxxxxxxxxx>
Subject: [AMC-list] 360 pistons
Message-ID: <004001caba55$f19c9dc0$d4d5d940$@charter.net>
Content-Type: text/plain; charset="us-ascii"
>Would it be of benefit to send him a STD bore 1970
high-compression?360?piston, as opposed to a low-compression dished piston?

My thinking is the best fit ALL AROUND would be a D-dish (with compression
distance moved up to maybe .010 in the hole). To allow honest 9-1 with 57cc
head. Would like to see 1/16 rings but I haven't looked to see if there's
any shelf stock that bore size.
9-1 with about a 220'@.050 cam should be about right for an automatic street
machine.
REALLY wake up those 360's !!!!! WITHOUT spending a lot of $$$$
I need to do some math for dish size,,,
But HEY,,, that's just ME!
Bruce Hevner
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