Is it late (July) to plant a lilac shrub and
Would it grow in part shade on the west side of property
The recommended sun exposure for lilacs is full sun, but they can grow with a minimum of 6 hours of direct sunlight. The lesser the light, the fewer blooms you will see, and the more susceptible lilacs will be to powdery mildew.
Lilacs also have a strong preference to well drained soil. Heavier wetter soils will also contribute to powdery mildew and other issues.
The preferred planting time is in the springtime, but if planted correctly at this time , and weather pattern remains not too hot, they can still be planted successfully. Some nursery stocks may become limited at this time, so be judicious in choosing healthy looking stock.
Good luck in your selection.