The Hart Company supplied an optional grain cleaner attachment for various Allis-Chalmers combines. It was inserted into the grain flow between the clean grain elevator and the bin or bagger. Installing it required some minor duct changes and an additional drive chain run from the top sprocket of the clean grain elevator. It works by fanning the grain around the inside of a cylindrical screen; material that passes through the screen is augered off to a bag, and the remainder is blown into the grain bin (or bagging setup).
Hart seems to have supplied several different versions of Scour-Kleen over the years, differing in the diameter and length of the cleaning cylinder. My two late Model 66s have a cylinder about 12" in diameter and 30" long. Older Model 66s I've seen had smaller cylinders. The Scour-Kleen applied to the smaller Model 40 All-Crop was only 7.5" in diameter and about 15" long. The only document I've found that describes this attachment is a dealer's repair manual for the Model 40. I've reproduced a couple of tables from it here:
| Size | Punching | Hart No. | Repair No. |
| 0.165 | Triangular | 1 | 504505 |
| 0.171 | Triangular | 0 | 504506 |
| 0.140 | Triangular | 2 | 504507 |
| 0.125 | Triangular | 3 | 504508 |
| 9/128 | Round | 4 | 504509 |
| 5/64 x 1 | Slotted | 4-1/4 | 504510 |
| 3/32 x 3/4 | Slotted | 4-1/2 | 504511 |
| 1/8 x 3/4 | Slotted | 5 | 504512 |
| 5/32 x 3/4 | Slotted | 6 | 504513 |
| 11/64 x 3/4 | Slotted | 7 | 504514 |
| 5/32 | Round | 8 | 504515 |
| 1/20 | Round | 9 | 504516 |
| 1/25 | Round | 10 | 504517 |
Quoting from the Model 40 manual:
"In the case of small seeds, if the dockage is larger than the seeds, it is sometimes desirable to reverse the cleaning process and to put in a large enough screen so that the seeds will pass through the screen and be delivered into the sack which is ordinarily for the dockage...."
"The Scour-Kleen Attachment for both the Grain Bin and Bagger Attachment is equipped at the Factory with the No.1 screen, which you will note from the chart is used for the common varieties of grains such as Wheat, Oats, Barley Etc."
| Kind of Grain | Used Most | Special Condition |
| 1 - Alfalfa | 9 | 4 - 10 |
| 2 - Barley | 1 | 0 - 2 - 3 |
| 7 - Beans, Soy | 5 | 4 1/2 - 6 - 7 |
| 9 - Buckwheat | 3 | 4 - 2 |
| 14 - Clover, Birdsfoot Trefoil | 10 | 9 - 4 |
| 21 - Clover, Red | 9 | 4 - 3 - 8 - 10 |
| 26 - Corn, Pop | 4 1/2 | 5 - 6 - 7 |
| 29 - Flax | 4 | 4 1/2 |
| 31 - Grass, Blue or June | 9 | 10 |
| 33 - Grass, Brome | 4 | |
| 45 - Grass, Sudan | 4 | 9 |
| 49 - Lespedeza, Korean | 9 | 4 - 10 |
| 54 - Millet, Common | 9 | 4 - 10 |
| 58 - Oats | 1 | 0 - 2 - 3 |
| 62 - Peas, Austrian Field | 4 1/2 | |
| 65 - Rice, Common | 1 | 0 - 2 - 3 |
| 67 - Rye | 1 | 0 - 2 - 3 |
| 69 - Spelt | 0 - 4 1/4 | 1 - 2 - 3 |
| 72 - Sunflower | 0 | 1 - 2 - 3 |
| 74 - Timothy | 9 | 4 - 10 |
| 76 - Vetch | 4 1/4 | 8 |
| 77 - Wheat | 1 | 0 - 2 - 3 |
| 79 - Beans, Bountiful | 7 | |
| 85 - Beans, Great Northern | 5 | 4 1/2 - 6 - 7 |
| 90 - Beans, Pinto | 6 | 7 |
| 95 - Peas, Table | 4 1/2 | 5 - 6 - 7 |
Sorry, I haven't gotten around to typing in the rest of the values.
I hope this has been useful - I would be quite glad to hear from anyone who has found a source of replacement screening - the screens themselves would be fairly easy to make given the punched raw material.
Maintained by James VanBokkelen.