http://www.ret-monitor.com/articles/940/a-load-of-hot-air/ Specific mission-critical info for professionals Mon, 21 May 2012 23:01:21 +0000 http://wordpress.org/?v=2.7.1 hourly 1 http://www.ret-monitor.com/articles/940/a-load-of-hot-air/comment-page-1/#comment-6160 Terry Thu, 20 Jan 2011 06:36:51 +0000 http://www.ret-monitor.com/articles/940/a-load-of-hot-air/#comment-6160 With very high speed racing engines, the pump volume scavenge/pressure ratios are probably closer to 4:1. Keeping dry-sump crankcase pressure below ambient with high scavenge ratios benefits ring sealing and helps reduce ring flutter. But more importantly, with very high rpm engines like in F1, keeping the crankcase as free from oil as possible is important for efficiency. Hydraulic windage losses due to crank webs, crank pins, and conrods churning through an air/oil mixture at high speed can be significant. Additionally, those windage losses produce heat loads into the lube oil. With very high speed racing engines, the pump volume scavenge/pressure ratios are probably closer to 4:1. Keeping dry-sump crankcase pressure below ambient with high scavenge ratios benefits ring sealing and helps reduce ring flutter. But more importantly, with very high rpm engines like in F1, keeping the crankcase as free from oil as possible is important for efficiency. Hydraulic windage losses due to crank webs, crank pins, and conrods churning through an air/oil mixture at high speed can be significant. Additionally, those windage losses produce heat loads into the lube oil.

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