* 4.2L Inline-Six: This was the standard engine option, producing around 220 horsepower.
* 3.6L Inline-Six: This was a smaller, less powerful option, offering around 175 horsepower.
It's important to note that these are just the basic engine sizes. There were also various different versions of each engine, with slightly different horsepower outputs and other variations.
To find the exact engine size of your specific 1986 Jaguar XJ6, you'll need to check the vehicle identification number (VIN) or the engine compartment.