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techtalk:miscres:miscres51 [2021/08/09 23:16]
hippysmack [How you can use casting numbers]
techtalk:miscres:miscres51 [2022/03/14 06:15] (current)
hippysmack [Circle Date Codes]
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 And HD may add their own stampings also before the part is fitted to a motorcycle. \\ And HD may add their own stampings also before the part is fitted to a motorcycle. \\
 So the casting or stamped numbers / letters / symbols etc. found in a part will denote many things other than part numbers. \\ So the casting or stamped numbers / letters / symbols etc. found in a part will denote many things other than part numbers. \\
 +Basically a casting number details a certain main design of a part. \\
 +That design may require other machining (holes, slots etc) before being classified as a part to be used in production. \\
 +The main design may simply require different finishes or colors for different models before being used in production. \\
 +The main design may also require other parts added (bearing race, sleeve for holes etc) before being used in production. \\
 +When the main design changed, so did the casting numbers, but not until then. However, the part number may change several times. \\
  
-Some parts will be identical when they are originally made by the vendor or whoever. \\+Some parts will be identical when they are originally made by the Moco or vendor or whoever. \\
 Then, one step toward the part's final production state may be adding a mounting hole for one model. \\ Then, one step toward the part's final production state may be adding a mounting hole for one model. \\
 But another model may not require one or may require the hole drilled in a different location. \\ But another model may not require one or may require the hole drilled in a different location. \\
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       * **Example 1**: 1957-1969 models use casting numbers to identify certain parts of the frame for year / model ID. \\ 57-69 models did not have a VIN number stamped in the frame. A serial number was stamped into the motor. \\ The only way to ID what year and model frame you have is to find and decode the casting numbers and known frame features. \\ [[techtalk:​ih:​body01w|Reference Ironhead Frame Identification]]       * **Example 1**: 1957-1969 models use casting numbers to identify certain parts of the frame for year / model ID. \\ 57-69 models did not have a VIN number stamped in the frame. A serial number was stamped into the motor. \\ The only way to ID what year and model frame you have is to find and decode the casting numbers and known frame features. \\ [[techtalk:​ih:​body01w|Reference Ironhead Frame Identification]]
       * **Example 2**: Casting numbers can be important when buying a used carb with the correct internals for your year model. \\ Keihin CV carbs have casting numbers and also the part number is on a sticker attached to the carb. \\ The stickers make it relatively easy to match the carb to what year model it was fitted to from the factory. \\ But sometimes the sticker goes missing (common after the carb sits in carb cleaner) or is unreadable. \\ Then you'll have to depend on the casting numbers and / or internal inspection. \\ However, casting numbers (only) were cast or stamped into early carburetors. \\ These markings identify type, body, jetting, motorcycle used for or modifications done to them. \\ [[techtalk:​ih:​carb01|Reference Links from the main IH Carburetor Page]]       * **Example 2**: Casting numbers can be important when buying a used carb with the correct internals for your year model. \\ Keihin CV carbs have casting numbers and also the part number is on a sticker attached to the carb. \\ The stickers make it relatively easy to match the carb to what year model it was fitted to from the factory. \\ But sometimes the sticker goes missing (common after the carb sits in carb cleaner) or is unreadable. \\ Then you'll have to depend on the casting numbers and / or internal inspection. \\ However, casting numbers (only) were cast or stamped into early carburetors. \\ These markings identify type, body, jetting, motorcycle used for or modifications done to them. \\ [[techtalk:​ih:​carb01|Reference Links from the main IH Carburetor Page]]
 +
 +====== Circle Date Codes ======
 +Many parts have a circle date code cast into them. This refers to the date the part was made (not the year model is was made for). \\
 +Generally the date code will be inside a cast-in circle with equal division blocks around the date in the center. \\
 +The division blocks will (most of the time) have dots stamped or blotted into the blocks to represent the month with the center number being the year. \\ 
 +Knowing the year season helps a lot. Generally you can look to June or July being the start of the next year season for production parts. \\
 +There most likely will be a layover between ending season and new season parts however. \\
 +So those two months are just a general point. \\  ​
 +
 +**Example**:​
 +If you have a cam cover with a circle date code (90) for the year 1990, it could have been made for either 1990 or 1991 model applications. \\
 +A circle date (90) and three division blocks blotted would indicate the part was cast in March, 1990 (late 1990 model season). \\
 +The part will generally be made for a 1990 bike. \\
 +A circle date (90) and eight division blocks blotted would indicate the part was cast in August, 1990 (early 1991 model season). \\
 +The part will generally be made for a 1991 bike. \\
 +Then compare features or known casting numbers, if applicable, for a positive year match. \\