Here's why:
* Different Bore & Stroke: The 1800 and 1600 engines have different bore and stroke dimensions. This means the cylinders are different sizes, and the head is designed specifically for the larger bore of the 1800 engine.
* Valve Placement: The valve placement on the 1800 and 1600 heads may also be different, even if the number of valves is the same.
* Port Size: The intake and exhaust ports on the 1800 head are larger to accommodate the larger airflow required by the 1800 engine.
Therefore, attempting to fit a 1800 head on a 1600 engine would result in a mismatch, leading to:
* Poor Combustion: The larger head will not seal properly on the smaller cylinders, causing combustion issues and potential damage.
* Valve Interference: The valves might not clear the piston due to the different design of the head and the engine block.
* Incorrect Manifold Alignment: The intake and exhaust manifolds would not match the port positions on the 1800 head.
It is crucial to use the correct engine head for your specific engine model. If you're looking to upgrade your 1600 engine, consider purchasing a 1600 head or finding a professional who can perform the modifications necessary for compatibility.
