Perhaps it’s a little premature to call it “priceless,” because you can rest assured that by the end of the day on Saturday, July 9, somebody will have cut a weighty check for this piece of American racing history. It’s a perfectly authentic 91-cu.in. supercharged Miller straight-eight engine, from the collection of the late David V. Uihlein, founder of the Harry Miller Meet at the historic Milwaukee Mile, where Mecum Auctions will sell the engine.

The auction of Uihlein’s trove of Miller pieces, some of them irreplaceable, will take place throughout the weekend of July 8-9. It is even more rare for a complete Miller engine of this vintage to become available, especially at absolutely no reserve, as this one is. Miller stunned the racing world when he unveiled the tiny, screaming engine to meet a change in rules for championship-level racing. The little straight-eight had a gear-driven centrifugal blower and four valves per cylinder. Frank Lockhart used a Miller 91 to set a one-lap speedway record on the Atlantic City board track in 1927 that stood until Jim Hurtubise broke it in qualifying for the 1960 Indianapolis 500. There’s no official pre-auction estimate, but a six-figure guess for this is probably reasonable. Find out more about the sale, and the Miller Meet, at www.harrymillerclub.com.