Identifying an unknown camshaft in your engine can be a challenge. Without knowing the camshaft specifications, it’s impossible to optimize engine performance. This article outlines the steps to effectively identify your camshaft.
Degreing the Camshaft
The most reliable method for identifying an unknown camshaft is by “degreing” it. This process involves measuring the precise timing of the camshaft’s opening and closing events relative to the engine’s crankshaft position. You’ll need a degree wheel, a dial indicator with a magnetic base, and a piston stop tool.
Gathering Necessary Measurements
- Top Dead Center (TDC): Determine TDC for cylinder #1 using the piston stop.
- Intake and Exhaust Valve Events: Using the dial indicator, measure the exact crankshaft degrees at which the intake and exhaust valves begin to open and close. Record these measurements as degrees Before Top Dead Center (BTDC) for opening events and degrees After Top Dead Center (ABDC) for closing events. You’ll need to rotate the engine manually and observe the indicator movement as each valve begins to lift and return to its closed position. Key measurements include:
- Intake Opens (IO): Degrees BTDC
- Intake Closes (IC): Degrees ABDC
- Exhaust Opens (EO): Degrees BBDC (Before Bottom Dead Center)
- Exhaust Closes (EC): Degrees ATDC (After Top Dead Center)
- Lobe Lift: At each valve’s maximum lift point, record the measurement from the dial indicator. This will help determine the camshaft’s lift profile.
Comparing Your Findings
Once you have collected the camshaft timing and lift data, you can compare it to known camshaft specifications.
Resources for Comparison
- Camshaft Manufacturer Catalogs: Many camshaft manufacturers publish catalogs with detailed specifications for their products. Look up camshafts with similar duration and lift numbers to your measured values.
- Online Camshaft Databases: Various online resources and forums dedicated to engine performance often have databases or discussions about camshaft identification. You can post your findings and ask for assistance in identifying your camshaft.
- Engine Building Forums: Engine building forums are a valuable resource for connecting with experienced enthusiasts and professionals who may be able to identify your camshaft based on your measurements.
Visual Inspection and Identifying Marks
While less precise than degreing, a visual inspection might provide clues.
Checking for Markings
- Casting Numbers: Examine the camshaft for any casting numbers or identifying marks stamped on it. These markings can sometimes be cross-referenced with manufacturer catalogs.
- Lobe Profile: Observe the overall shape and size of the cam lobes. Compare these visual characteristics to known camshaft profiles.
Conclusion
Identifying an unknown camshaft requires careful measurement and analysis. By degreing the camshaft and gathering accurate timing and lift data, you can compare your findings to known camshaft profiles and potentially identify the specific camshaft in your engine. While visual inspection might offer some clues, degreing provides the most accurate and reliable method for identification. This information is crucial for understanding your engine’s performance characteristics and making informed decisions about tuning and modifications.
