[{"id":284382593137,"handle":"all-parts-and-engines","title":"All Products","updated_at":"2026-03-19T15:20:08+11:00","body_html":"\u003cp\u003eAll Atomic Performance Products\u003c\/p\u003e","published_at":"2024-12-30T19:16:03+11:00","sort_order":"best-selling","template_suffix":"","disjunctive":true,"rules":[{"column":"variant_title","relation":"not_equals","condition":"0"}],"published_scope":"global","image":{"created_at":"2025-01-16T20:22:01+11:00","alt":null,"width":3000,"height":4000,"src":"\/\/atomicperformanceproducts.com\/cdn\/shop\/collections\/20241008_155351.jpg?v=1737019322"}},{"id":280910168177,"handle":"block","title":"Block","updated_at":"2026-03-18T22:14:49+11:00","body_html":"\u003cp\u003eAtomic engine block parts including standard and destroke cranks, billet conrods, pistons, main caps, girdle, main studs, oil system componens, sump\u003c\/p\u003e\n\u003c!----\u003e","published_at":"2024-08-05T23:32:10+10:00","sort_order":"best-selling","template_suffix":"","disjunctive":true,"rules":[{"column":"type","relation":"equals","condition":"Conrods"},{"column":"type","relation":"equals","condition":"Crank"},{"column":"type","relation":"equals","condition":"Girdle"},{"column":"type","relation":"equals","condition":"Pistons"},{"column":"type","relation":"equals","condition":"Sump"},{"column":"type","relation":"equals","condition":"Oil System"},{"column":"type","relation":"equals","condition":"Main Caps"},{"column":"type","relation":"equals","condition":"Engine Block"}],"published_scope":"global","image":{"created_at":"2024-08-06T00:00:07+10:00","alt":null,"width":1305,"height":813,"src":"\/\/atomicperformanceproducts.com\/cdn\/shop\/collections\/550_gta_short.png?v=1723016162"}},{"id":292910465137,"handle":"featured","updated_at":"2026-03-16T22:16:05+11:00","published_at":"2025-09-23T18:22:42+10:00","sort_order":"manual","template_suffix":"","published_scope":"global","title":"Featured","body_html":"","image":{"created_at":"2025-09-23T18:22:41+10:00","alt":null,"width":1596,"height":591,"src":"\/\/atomicperformanceproducts.com\/cdn\/shop\/collections\/Atomic_Barra_1000hp_Capable_Parts_Package.png?v=1758615761"}}]
Made out of a high grade 4140 which is preferred for Barra main caps. Costs more but it's ~45% stronger but essentially, not too hard! This is important because if the caps are harder than the block is becomes very difficult to get perfect roundness on the tunnel bore. The hardness of 4140 is just right to make them strong but avoid making the caps brittle.
Fixed the offset tunnel found on other options which makes machining harder and cost more
Fixed the depth and width of the bearing tang groove so that bearings aren't being pinched and distorted or twisted
Made by a repetition style machinist with custom fixturing to ensure great dimensionality and consistency
Clearly marked with a window to engrave the blank caps once assigned
Please note that that hardness listed for 1045 represents the brinell value. HRC value is roughly 8-10.
