The number of cylinders doesn't matter. What does matter is the number of valves. There is one valve guide per valve.
This depends on how many valves per cylinder. some have one Intake and one exhaust. some have two each per cylinder. I've even seen engines with two intakes and one exhaust........
So the answer is contingent upon the design of the particular engine.
What engine?
Usually between 8 and 20.
A simple engine will only have 2 valves per cyl.
My old Toyota had a 4AGE engine with 5 valves per cyl, 20 in total.
