When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Do you mean cranking speed by "tick over"? If so, not much. My needle would just bounce off the bottom when last I was building pressure from scratch. S/B ~30 @ idle & ~60 @ 3k+.