{"id":75539,"date":"2020-10-22T10:03:46","date_gmt":"2020-10-22T17:03:46","guid":{"rendered":"https:\/\/www.racingjunk.com\/news\/?p=75539"},"modified":"2020-11-25T05:00:00","modified_gmt":"2020-11-25T13:00:00","slug":"jesels-new-steel-sportsman-rockers-part-1","status":"publish","type":"post","link":"https:\/\/www.racingjunk.com\/news\/jesels-new-steel-sportsman-rockers-part-1\/","title":{"rendered":"Jesel&#8217;s New Steel Sportsman Rockers Part 1"},"content":{"rendered":"<p class=\"jetpack-slideshow-noscript robots-nocontent\">This slideshow requires JavaScript.<\/p><div id=\"gallery-75539-1-slideshow\" class=\"jetpack-slideshow-window jetpack-slideshow jetpack-slideshow-black\" data-trans=\"fade\" data-autostart=\"1\" data-gallery=\"[{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2020\\\/10\\\/rocker-1-min-scaled-e1603386110689.jpg&quot;,&quot;id&quot;:&quot;75540&quot;,&quot;title&quot;:&quot;Jesel\\u0026#8217;s New Steel Sportsman Rockers Part 1&quot;,&quot;alt&quot;:&quot;&quot;,&quot;caption&quot;:&quot;Roughly five years ago, we ran a series on shaft rockers.\\u00a0 That series explained why and how shaft work rockers work so well in race (and street-strip) applications.\\u00a0 In that series we mentioned how Dan Jesel (www.jesel.com) pretty much invented the new breed of rockers:\\u00a0 \\u201cIn something like a small block Chevy application, the stock rocker has a relatively short pivot length.\\u00a0 This means the arc it travels in is comparatively small, particularly in contrast to other pushrod engines (Jesel notes that a stock small block Chevy has a rocker pivot length of 1.45-inches.\\u00a0 In comparison, a big block has a pivot length of 1.65-inches).\\u00a0 What this all means is the stock small block rocker arm tip more or less scrubs across the tip of the valve as it opens.\\u00a0 This isn\\u2019t much of an issue at lower gross valve lifts such as those experienced with stock or mild camshafts (such as those used in production engines).\\u00a0 But when you increase the lift dramatically (as seen in today\\u2019s race engines) and simultaneously increase the spring pressure you\\u2019re soon faced with another quandary:\\u00a0 An increase in friction.\\u201d\\n\\nEssentially, the new Jesel shaft rockers were a means to improve upon the rocker geometry of a small block Chevy. The shaft rocker system wasn\\u2019t bound by the rocker stud location on the cylinder head, and it allowed Dan Jesel to move the rocker in a position on the head where it wasn\\u2019t scrubbing.\\u00a0 Over the decades, that line of thinking expanded to function on all sorts of engines and all sorts of cylinder heads.\\n\\nThere was also a bit more to the equation:\\u00a0 Replacing a conventional rocker setup\\\/stud girdle combination saves a lot of work when you\\u2019re performing simple maintenance such as lashing the valves.\\u00a0 Here\\u2019s an excerpt from that older series and it still holds true today:\\u00a0 \\u201cTypically, the drill (valve lash) went like this:\\u00a0 First you loosen the stud girdle, and then you lash the valves. The girdle is re-tightened and finally most folks check the valve lash once more.\\u00a0 If the studs are the least bit out of alignment, tightening the stud girdle changes the valve lash. Not fun.\\u00a0 But you also have to be extremely careful with clearances on some combinations \\u2013 the rockers and girdle can touch, which obviously spells more (and bigger) trouble.\\u201d\\n\\nNow that\\u2019s the backstory. Over the years, Jesel has refined their complete line of rockers considerably. They offer all sorts of combinations for an almost dizzying array of cylinder heads (as a sidenote, Jesel pretty much keeps in stock, a complete selection of sample heads from which they engineer and manufacture rockers).\\u00a0 Many of those rocker combinations offer multiple options too.\\u00a0 And one of the latest rocker combinations available from the folks at Jesel is the steel body Sportsman Rocker.\\n\\nAccording to Jesel:\\u00a0 \\u201cJesel Engineers have combined all of the features of our Pro Aluminum Rockers with the durability of our Pro Steel Rockers. Jesel Sportsman Steel Rockers provide engine builders with the option of high strength steel rockers at an extremely affordable price and can be ordered separately or as an upgrade to certain Pro Aluminum rocker systems.\\u201d\\n\\n\\u201cThe Jesel Sportsman Steel Rockers are assembled with all of the proven components of our Pro Aluminum rockers. Featuring a 0.625\\u0026#8243; wide body with an ultralight slot to reduce weight and moment of inertia. They\\u2019re designed to be a direct replacement for the current Pro Aluminum bodies and will bolt to existing stands. Featuring a 0.360\\u0026#8243; wide non-needle valve tip roller and cup style tool steel adjuster, the rockers can be optioned with needle bearing nose rollers and ball style lash adjusters for high lift \\\/ high spring pressure applications. The rocker geometry is designed to minimize roller movement on the valve tip and each rocker body is manufactured from premium alloy steel. A through hardened heat treating process along with a black oxide coating will provide for years of dependable service and corrosion resistance.\\u201d\\n\\nWhat didn\\u2019t change with the steel rocker option for the Sportsman rocker kits was the fact they allow for longer pivot length rockers, various rocker ratios,\\u00a0 adjustable stand heights and they still incorporate easy to adjust valves that maintain lash adjustment, race-after-race.\\n\\nNext issue, we\\u2019ll dig deeper into the Jesel Steel Sportsman Rockers.\\u00a0 You\\u2019ll find the innovations are considerable.\\u00a0 Watch for it and in the meantime, check out the accompanying slide show:\\n\\nClick Here to Begin Slideshow&quot;,&quot;itemprop&quot;:&quot;image&quot;},{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2020\\\/10\\\/rocker-2-min-scaled.jpg&quot;,&quot;id&quot;:&quot;75541&quot;,&quot;title&quot;:&quot;Jesel\\u0026#8217;s New Steel Sportsman Rockers Part 1&quot;,&quot;alt&quot;:&quot;&quot;,&quot;caption&quot;:&quot;One of the major benefits found in the Jesel shaft rocker system is that design isn\\u2019t constrained by the rocker stud location.  The stand locates the rocker, not the location of the rocker stud threads.&quot;,&quot;itemprop&quot;:&quot;image&quot;},{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2020\\\/10\\\/rocker-3-min-scaled.jpg&quot;,&quot;id&quot;:&quot;75542&quot;,&quot;title&quot;:&quot;Jesel\\u0026#8217;s New Steel Sportsman Rockers Part 1&quot;,&quot;alt&quot;:&quot;&quot;,&quot;caption&quot;:&quot;The way a rocker arm contacts (or scrubs across) the tip of the valve has a huge effect upon horsepower, efficiency and reliability.&quot;,&quot;itemprop&quot;:&quot;image&quot;},{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2020\\\/10\\\/rocker-4-min-scaled.jpg&quot;,&quot;id&quot;:&quot;75543&quot;,&quot;title&quot;:&quot;Jesel\\u0026#8217;s New Steel Sportsman Rockers Part 1&quot;,&quot;alt&quot;:&quot;&quot;,&quot;caption&quot;:&quot;The method to mount the rocker is important.  Here, we\\u2019re setting up a shaft system on a Brodix big block Chevy cylinder head.  We\\u2019ll dig deeper into this down the road.&quot;,&quot;itemprop&quot;:&quot;image&quot;},{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2020\\\/10\\\/rocker-5-min-scaled.jpg&quot;,&quot;id&quot;:&quot;75544&quot;,&quot;title&quot;:&quot;Jesel\\u0026#8217;s New Steel Sportsman Rockers Part 1&quot;,&quot;alt&quot;:&quot;&quot;,&quot;caption&quot;:&quot;The ultimate weight of the rocker arm is important, but there\\u2019s more to it than overall weight.  Here you can see a 1.7:1 ratio Jesel Sportsman rocker for a big block tips the scale at 192 grams.&quot;,&quot;itemprop&quot;:&quot;image&quot;},{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2020\\\/10\\\/rocker-6-min-scaled.jpg&quot;,&quot;id&quot;:&quot;75545&quot;,&quot;title&quot;:&quot;Jesel\\u0026#8217;s New Steel Sportsman Rockers Part 1&quot;,&quot;alt&quot;:&quot;&quot;,&quot;caption&quot;:&quot;In comparison, a 1.7:1 ratio Jesel Steel Sportsman rocker weighs 246 grams. Mass Moment of Inertia (MMI) is likely more important, and we\\u2019ll look at that in the next issue.&quot;,&quot;itemprop&quot;:&quot;image&quot;}]\" itemscope itemtype=\"https:\/\/schema.org\/ImageGallery\"><\/div>\n","protected":false},"excerpt":{"rendered":"<div class=\"mh-excerpt\"><p>Wayne Scraba goes over what you need to know about some new rockers. <\/p>\n<\/div>","protected":false},"author":20,"featured_media":75540,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[5028,3697,5008,17,11,3470,4879,22],"tags":[281,5380,41,8085,4102,4888,321],"class_list":["post-75539","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-fuel-delivery","category-galleries","category-engine","category-guest-column","category-how-tos","category-news","category-slideshow","category-event-coverage","tag-how-to","tag-jesel","tag-news","tag-rockers","tag-shaft-rockers","tag-slideshow","tag-wayne-scraba"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2020\/10\/rocker-1-min-scaled-e1603386110689.jpg","jetpack_shortlink":"https:\/\/wp.me\/p42YSK-jEn","jetpack_sharing_enabled":true,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/75539","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/users\/20"}],"replies":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/comments?post=75539"}],"version-history":[{"count":1,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/75539\/revisions"}],"predecessor-version":[{"id":75546,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/75539\/revisions\/75546"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media\/75540"}],"wp:attachment":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media?parent=75539"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/categories?post=75539"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/tags?post=75539"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}