Stampings are found on several parts of the Cosworth's body and drivetrain. By stampings we mean letters and/or numbers that are physically "stamped" or "impressed" into metal parts of the vehicle. These stampings are many and varied, and we confess that we do not know the origin or purpose of many.
What follows is a non-exhaustive list of the stampings we have found on the Cosworth Vega.
If you locate and can identify any additional stampings, please document them and forward an explanation and some high resolution images to the WebCrew.
One traditional "use" of certain stampings on collector cars is to verify that the vehicle contains the parts that were installed by the factory or that would have been installed. Narrowly defined, a "numbers matching" car is one in which the engine and often the transmission are marked with a portion of the body VIN--i.e. a partial VIN. When the partial VIN stampings on the engine and transmission in such a car match the VIN on the body, the car can be touted as a "numbers matching" car. But the numbers matching concept traditionally extends beyond that simple rule. It more often means that all date coded parts, e.g. the differential, were manufactured prior to the production date of the vehicle. In the most extreme cases, where there are identical stampings (or, as in the case of the Cosworth Vega, identical stickers) on several parts, then those numbers must all agree in order for the car to be a "true" numbers matching car. With these concepts in mind, the WebCrew offers the following as standards for determining whether a Cosworth Vega is or is not a "numbers matching" car.
There are two footnotes to these proposed standards. First, the EFI stickers do not correlate to any other vehicle component. Accordingly, they must only match among themselves. Second, only the 5-speed transmissions contain a partial VIN, and they were only available in 1976.
The "Tonawanda Number", also known as the "Engine Number", is the number that is stamped into the rear faces of the cam carrier, cylinder head, and cylinder block. While many believe that all Tonawanda Numbers are 4 digits, in fact instances of two and three digit Tonawanda numbers have been documented. For example here is a three digit number:
Presumably there are, or at least were, single digit Tonawanda numbers, but none have been located by the WebCrew.
Below is a photo of the rear faces of the cam carrier, cylinder head, and engine out of #3371, the White Tornado Cosworth, a 17k mile car that was photo-documented as it was carefully dismantled. This is an atypical example! This engine sports not one but two Tonawanda numbers, and not one but two different (and three altogether) stamps embedded by two engine testers: one is a Triangle Q stamp and two are Square 2 stamps. While the WebCrew does not know the reason for the plethora of stamps on this head, they suspect that the head was originally installed on another engine that did not survive the engine test procedure and was re-used on a different engine built later in the production run. While it may or may not be siginificant, this engine was assembled by Carl J. Kooken, the first worker assigned to assemble these engines, and, by seniority, the last worker to assemble them as well.
Here is the photo of the rear face of the engine. The Tonawanda Number of this engine is the four digit 3935 number stamped into each of the components.
Cosworth Vega engines were test-run at the factory before being shipped to Lordstown for installation. When an engine passed this test, the engine tester used a hammer with a geometrical shape surrounding either a number or a letter to indicate that he had tested it and that it had passed the run-in test.
Below is a chart containing the Tonawanda Numbers of various cylinder heads and the geometrical shapes and the numbers/letters they surround that are found on each head. The WebCrew is looking to add to this list, so if you have your engine out or head off, please send us a photo of or an email describing the back of the head so we can add your data to this chart.
|Head Stampings Per Tonawanda #|
The engine block of installed engines contains a stamping of part of the VIN. If your Cosworth block does not contain a partial VIN, then it is most likely a replacement block.
Not all partial VINs were clearly stamped into the block. As of this writing the exact method used to stamp the VIN into the block is unknown. From the uniformity and registration of the partial VIN characters, it appears that a tool containing the entire partial VIN was used. If anybody has any specific information on this technique, please send the WebCrew a Feedback.
The partial VIN was stamped into the bellhousing flange just above and inboard of the opening for the starter. Check out this photo.
As you can see from this photo, the partial VIN is in the format 16UXXXXXX, and the stamping is uneven. In the case of the pictured VIN, 16U226195, the "6" represents the 1976 model year. The 1975 model year blocks should be in the format 15UXXXXXX.
The coded stamping that evidences the build date of the engine is also located atop the bellhousing flange, in the neighborhood of the 12:00 position, directly in the center of the block.
The stamping is coded. It is in the format TXXXXZCX, where "X" is a variable, either a number or a letter. In practice, there were only two formats, TXXXXZCA and TXXXXZCB. The difference between "A" and "B" is the difference between a 1975 model year engine and a 1976 model year powerplant.
Further decoding the stamping, the T represents Tonawanda. The WebCrew once knew the significance of the ZC, but alas has temporarily forgotten. If anyone can refresh our recollections, please send us a Feedback.
Finally, the four middle characters are digits and represent the month and day of the engine build. Check out this photo of the build date stamping. It reads T0420ZCB, although the "B" is not well indented and is difficult to read through the corrosion on the bellhousing flange. Translated, this means that this motor was completed on April 20, 1976 at the Tonawanda, NY factory. What is not revealed, but what is known according to the build sticker, is that the motor was built and signed by none other than Carl J. Kooken.