found these on a surplus site, says for B-17 & B-24s

[JOHN MILLER]

http://www.sciplus.com/new.cfm

B-17 & B-24 Motors

These small, new motors for oil-heater louvered doors were made for, but never installed in, WWII-era B-17s and B-24s. High torque, low rpm, these collectible 12VDC 1.5A motors measure 5-1/8" long x 3-1/2" dia on the shaft side and 2-3/8" dia on the other end, in a blunted bullet shape. The 15-tooth output shaft is 3/4" long x 1/2" dia, centered on the large end with a trim screw offset for some speed control, and a 4-pin Amphenol connector. Will take up to 26VDC. These are of particular interest to us because the sample, at least, was manufactured right down the road from us in Rockford, Illinois, by the Barber-Colman Company!
39972 WW II B17/B24 AIRCRAFT CONTROLLER MOTOR
$24.50 EAC

[Rod Schneider]

Hmmmm.......they resemble the electric motor used in the B-17 to select filtered or non filtered air for the engines. Should be for a 28 volt system though.........

[CrewDawg]

I agree with Rob, they look like the filtered/non-filtered air door motors, but the voltage isn't right........ The number 39972 is not in the B-17 Illustrated Pars Catalog Numerical Index. Figure 36 item 23 lists P/N AYLC5091 Motor (Barber Coleman) ad the carb air motor for all B-17G's. Perhaps this is for an earlier model B-17? I wonder if the 26 VDC is a typo?

With that said, I don't see a big demand for these. Most B-17's fly all the time using filtered air because they rarely go over 10,000 feet. Per the manual they are to use filtered air below 8,000 feet because there is more dirt and debris in the air at lower altiitudes, and switch to non-filtered air above 8,000 ft.

[Chuck Giese]

In addition, the oil-cooler louver doors are not electrically activated.