You might ask why do I need to measure my piston. Here at Emmark we are often asked the question how do I know which piston is in my engine when I don’t know the engine number.
Assuming we know what type of engine i.e. Ford, Perkins, John Deere, Case-IH then the bore size needs to be determined, this will focus the engine type within a certain range, but then it is more than likely there will be several different engines made by each manufacturer with the same bore size, this is where we need to dimensionally measure the piston to identify the correct piston for your engine.
1. Compression Height
The compression height of any piston is the measurement from the centre of the gudgeon pin or wrist pin as the Americans call it to the top of the crown of the piston, see below.
The easiest way to measure is with a pair of digital Vernier gauges, measure from the top of the pin hole to the top of the piston. Make a note of that measurement, then measure the pin diameter and half it. Add half the pin diameter to the first measurement you made a note of. This will give your compression height. This does not provide 100% accurate value but is close enough to assist in identifying your piston. Check out our next technical blog coming soon.
2. Length
3. Combustion Bowl
4. Combustion Bowl Type
5. Pin diameter
6. Number of Rings
7. Oil Cooled Crown
8. Skirt Type
All of these points we will deal with in following blogs.
Check out our Technical blogs for any other help you may need and feel free to ask us.