With two-cylinder compounds used in railway work, the pistons are connected to the cranks as with a two-cylinder simple at 90deg out of phase with each other (quartered). When the double expansion group is duplicated, producing a 4-cylinder compound, the individual pistons within the group are usually balanced at 180deg, the groups being set at 90deg to each other. In one case (the first type of Vauclain compound), the pistons worked in the same phase driving a common crosshead and crank, again set at 90deg as for a two-cylinder engine. With the 3-cylinder compound arrangement, the LP cranks were either set at 90deg with the HP one at 135deg to the other two, or in some cases all three cranks were set at 120deg.[citation needed]
In a 4-cylinder compound engine, what degree were the individual pistons balanced at?
180deg
When the double expansion group is duplicated, producing a 4-cylinder compound, the individual pistons within the group are usually balanced at 180deg, the groups being set at 90deg to each other.
the individual pistons