The Secret Engine (1) - S1.E5

Speed, Spritle, and Chim Chim take the Mach 5 out for a test drive. The radio announces that Tongue Blaggard has escaped from prison. The Racers meet a girl and her grandfather whose Model T has broken down on the road. Speed offers to help, but the old man declines.

Later, the Racers find the broken down Model T again. This time, the old man accepts Speed's help. While the Racers dine with the old man, the granddaughter, and his adopted children, Blaggard steals the Model T, hoping that it is the one that once belonged to the crook Light Fingers Clepto. Speed vows to recover the stolen vehicle. The old man, unashamed, tells who his father was. Trixie spots the Model T from her helicopter and brings it into Pops' garage for repairs. Before long, a line of Model T's has formed, all with engine trouble. Speed finds this peculiar and uncovers the old man's original engine, finding a secret code number etched on it by Light Fingers Clepto (the old man's father).