One of the truly great engines of all time, a supercharged Miller 91 will hit the auction block in Milwaukee next month as part of the Mecum auction happening in conjunction with the Millers at Milwaukee event. This engine, completely hand built from the oil pan to the valve cover still stands today as an incredible piece of engineering. Think about it. In the 1920s, this 91ci mill was making more than 280hp with a Miller centrifugal blower strapped to the front of it.

The man whose name graces the engine, Harry Miller was an absolute titan in auto racing during the first half of the 20th century. His cars dominated the Indy 500, board tracks, and dirt tracks from coast to coast. Their engineering was lightyears ahead of anyone elses and virtually all of the innovative ideas and thought sprang from Miller’s fertile mind. Books have been written about the man.  

If you are engine dweebs like us, you’ll view Miller’s “91” as one of his crowning achievements. The mill eventually evolved into the world beating “Offy”, but even in the early stages of it’s life, the engine was a marvel. In many ways, it still is.

To think that these were all totally hand made by true craftsmen is pretty neat. The fact that it was making more than 3hp per cubic inch in an era where most of the world still rode horses is (in a vastly overused term) epic.  

Here’s what the guts of a Miller 91 look like:

Cylinders: 8 (in line configuration)

Bore/Stroke: 2.18×3″

HP: 285 @ 8100RPM (supercharged)

Compression Ratio: 9 to 1

Engine weight: 330lbs

Block: Two piece cast iron with integral cylinder head

Camshaft: Dual overhead

Valves: Two valves per cylinder in hemispherical combustion chamber

Valve size: Intake – 1.25 inches — Exhaust – 1.18 inches

Bearings – Connecting Rods — Poured white metal — Mains — Bronze bushing in front and all the rest poured

Oiling system: Dry Sump with 4.5 gallons of capacity

Carbs — Winfield

Blower: Miller Centrifugal with 8-inch impeller (blower is 20% overdriven)

Want to buy it? Read the release from Mecum Auctions below and get your bidding cash ready!

MARENGO, Ill. – Mecum Auctions has announced it will offer motors, parts and memorabilia from the collection of David Uihlein during the 17th Annual Millers at Milwaukee Vintage Indy Car Event taking place July 8-9, 2011, at the Milwaukee Mile Oval Track, Wisconsin State Fair Park.

The auction will be held from 8-11 a.m. on Saturday, July 9, and will feature hundreds of items all offered at no reserve. Headlining the sale is a Miller 91 supercharged engine, and items will be on display for preview on Friday and Saturday in the Media Center at the Milwaukee Mile.

David Uihlein Sr. was well known in the vintage Indy car circuit as the founder of The Harry A. Miller Club. Each year, the club hosts the two-day Millers at Milwaukee event, which attracts collectors and enthusiasts of antique race car engine designer Harry A. Miller and features front engine pre- and post-WWII Indy cars, Champ cars and Roadsters. The gates at the Milwaukee Mile will open at 11 a.m. Friday, July 8, with cars running the oval track from 11 a.m.-4 p.m. On Saturday, gates will open at 7 a.m. for auction participants with cars starting on the track from 11 a.m.-4 p.m.

Attendees can pre-register to bid for the auction for free by visiting www.Mecum.com or calling 815.568.8888. General admission to the event is handled by The Miller Club, and the $25 per person ticket covers both days and includes parking. For complete details, visit www.harrymillerclub.com.