Race Against Time (novel series)

Race Against Time is a series of juvenile action/adventure books published from 1984 to 1985, by an author listed only as J. J. Fortune.
Background.
Most of the action are narrated through a young New York teen named Stephen Lane, who is a movie buff, who always get caught up in some madcap adventures of his uncle, Richard Duffy. Until mother's younger brother moved in with the family into their brownstone on 224½ East 61st Street one day, Stephen spent most of his weekends and other free time watching videos, from old movies to the latest action flicks.
The Lane family only know that Richard Duffy was an engineer who retired unusually young for someone in profession. What they did not know was that he was an adventurer who "blew up more bridges than he built", a highly skilled operative who worked with various government special agencies around the world, and incidentally, made many enemies in his past. His retiring young was due to his coming into ownership of what was thought to be a spent gold mine. Perhaps for the one and only time in his life, he actually managed to put his engineering knowledge into good use to continue extracting gold from the mine.
Plot Outlines.
Most of the adventures occur in the absence of Mr. and Mrs. Lane from the household. Mr. Lane is a successful stockbroker who always try to pry (but never successful) into the source of Richard's financial means. Mrs. Marion Lane (née Duffy) ran a health food store named "Oh Nuts!" Things usually happened when both parents went together on weekend business trips (either his or hers). They left Richard to babysit Stephen, expecting nothing more than a prosaic time together for the uncle-nephew duo. However, almost as soon as they left the house, someone or something from Richard's past appeared and sent the duo flying across the world (most of the time), to solve some difficult problems. Invariably, there would be a beautiful woman involved, sometimes from Richard's past, sometimes someone new.
The eponymous title of the series came from the time limit the duo had to reach their destination, solve the problem and be back at home before Stephen's parents return, without giving away the slightest hint of what they had been up to.
Crucial to their success, apart from Richard's skills and experience as an adventurer, was his practically unlimited finances, and their special Kronom K-D2 watches with technology far more advanced than was actually available in the 20th century.
The series was published by Dell (NY) for the US editions, and Armada (London) for the UK editions.
Titles in the series.
There were 10 books published in this series:
The order of publication in the US and UK differed slightly.
Kronom K-D2.
Kronom K-D2 is the model of a fictional computer-watch that played a significant role in the novel in solving problems.
Its initial mention was in chapter one the first novel of the series, but the name Kronom K-D2 only came up for the first time in chapter two of the second novel.
Background of the watch.
During their first adventure together, Richard Duffy gave Stephen his spare Kronom K-D2, and left it to Stephen to figure out the various functions. Later, he explained that there were only three models in the whole world, and he had two of them, the third being in the possession of a villain known as the Mole.
Richard revealed that the Kronom K-D2 was the brainchild of Karl Wolfmann, a genius Swiss watchmaker. After one of the prototypes was stolen by the maker's assistant, a number of crimes were committed which Wolfmann realized were done using the watch. Deciding to keep the watch a secret, he destroyed all the notes related to its creation, but could not bear to do the same to the remaining two models. These were entrusted to Richard who promised to only use it for good, and to hunt down the Mole, the thief of the third watch and who was responsible for these crimes.
Some of Richard Duffy's past adversaries realized his was not an ordinary watch. The villain known as the Shark from the third novel knew it well enough to seize it from Richard when he had the chance (chapter seven).
In chapter eleven of The Secret of the Third Watch, Richard and Stephen were held captive by the Mole, who told them that it was his idea, as Wolfmann's assistant, to introduce many features into the design of the Kronom K-D2, which he would later use in his crime spree.