{"id":136,"date":"2010-03-28T23:53:04","date_gmt":"2010-03-29T06:53:04","guid":{"rendered":"http:\/\/specialtyz.com\/blog\/?p=136"},"modified":"2013-09-15T15:18:11","modified_gmt":"2013-09-15T22:18:11","slug":"piston-selection-alloys","status":"publish","type":"post","link":"http:\/\/blog.specialtyz.com\/?p=136","title":{"rendered":"Piston Selection (alloys)"},"content":{"rendered":"

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This isn’t an end all on which piston is the best or a detailed discussion into piston design.\u00a0 This is just something to be aware of when selecting pistons.\u00a0 A big misconception on “built” engines or more precisely speaking piston selection can be misinterpreted.\u00a0 A forged piston is by far stronger than a factory cast pistons but there’s more to it than just that.\u00a0 What do you realistically plan to do with your engine? Will you be daily driving the car?\u00a0 Can you put up with a noisier engine?\u00a0 Carefully think about what you plan to do.\u00a0 If your planning on competitively racing, run very high boost pressures and\\or nitrous and can deal with servicing your engine more frequently;\u00a0 than a 2618 forging would be up your alley.\u00a0 Most factory aluminum pistons are eutectic and hypereutectic.\u00a0 What’s important to know about this is that these pistons have a higher silicon content which allows the piston to have tighter clearances for a quiet, long lasting engine.\u00a0 The amount of silicon is directly proportional to how ductile the piston is.\u00a0 Meaning just how “hard” or “soft” the alloy is.\u00a0 Pistons that have high silicon are technically strong since their alloy has a tighter bond at the molecular level, BUT they’re also much more brittle and don’t stand up to detonation as well as a forged piston with less silicon content.\u00a0 Your piston also isn’t the only part of your engine that’s taking abuse from detonation.\u00a0 More on that some other time.<\/p>\n

Something in between a 2618 and a factory piston alloy would be the 4032 alloy.\u00a0 These have more silicon content than a 2618 alloy but no where near as high as a factory piston.\u00a0 The clearances on these engines can be tighter than a 2618 for less noise and wear than a 2618 alloy.\u00a0 A majority of the wear seen on a forged engine is when the engine is warming up.\u00a0 You may have heard of the term “piston slap”.\u00a0 This is the term used for a piston rocking around in the bore until it gets up to operating temperature and expands.\u00a0 This rocking causes wear on the rings and of course on the pistons themselves.\u00a0 Clearances on a 2618 and 4032 alloys need to\u00a0 be “looser” to accommodate the piston when it expands as it gets hot.\u00a0 This would be when it finally warms up, sees boost, etc….\u00a0 Its best to allow a forged slugged engine to warm up until piston slap can no longer be heard before driving.\u00a0 The popular Wiseco pistons use a 4032 alloy for best of both worlds.\u00a0 It still won’t last as long as a factory piston but it is stronger and won’t wear out as fast as a 2618 alloy.<\/p>\n

Typically, Japanese engines have very tight tolerances from the factory to have a “sewing machine” like operation.\u00a0 Nice, quiet, and reliable (long lasting).\u00a0 Hopefully this has helped some of you make an educated decision when selecting your next piston forging, instead of simply choosing the strongest “best” piston.\u00a0 The term best has a relative meaning.\u00a0 What’s “best” for your application?<\/p>\n","protected":false},"excerpt":{"rendered":"

This isn’t an end all on which piston is the best or a detailed discussion into piston design.\u00a0 This is just something to be aware of when selecting pistons.\u00a0 A big misconception on “built” engines or more precisely speaking piston selection can be misinterpreted.\u00a0 A forged piston is by far stronger than a factory cast […]<\/p>\n","protected":false},"author":1,"featured_media":138,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,1],"tags":[],"class_list":["post-136","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-builds","category-general"],"aioseo_notices":[],"_links":{"self":[{"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=\/wp\/v2\/posts\/136","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=136"}],"version-history":[{"count":11,"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=\/wp\/v2\/posts\/136\/revisions"}],"predecessor-version":[{"id":2417,"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=\/wp\/v2\/posts\/136\/revisions\/2417"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=\/wp\/v2\/media\/138"}],"wp:attachment":[{"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=136"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=136"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.specialtyz.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=136"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}