A huge act of generosity involving at least 10 years of intricate engineering has resulted in Tauranga's Classic Flyers Museum becoming the proud owner of a unique collection of working scale model aircraft engines.
The 13 engines were donated by 82-year-old retired cabinet maker Bill Janes who has a passion for modelling that dated back to his early childhood.
"I am well versed in the idiosyncrasies of old machinery," he said.
He made everything that went into the engines except for the valve springs. "It took about nine months to make one engine."
His gift to the museum depicted the evolution of piston-powered aero engine design, from a 1909 de Havilland to a 1970s era Continental engine that powered Cessnas.
Classic Flyers chief executive Andrew Gormlie described them as a lovely acquisition.
"We are very pleased that Bill thought of us. We will look after them."
Viewing was by appointment although they were planning special displays where people wandering through the museum would be able to admire them.
"These engines almost defy description because of their complexity and accuracy."
Almost all the components were machined from scratch in Mr Janes' workshop with little more than a lathe and milling machine.
Mr Gormlie praised the painstaking detailing of each engine, saying Mr Janes was a rare man who achieved an engineering feat of huge proportions.
"It is a very generous thing that he has done."
Mr Janes' deep love of machinery has included restoring nine veteran and vintage cars from the ground up.
"I have been a busy boy over the years,'' he said from his Gate Pa home yesterday."
A huge amount of planning and preparation went into building each aircraft engine, with most involving meticulous research.
He finished making his last engine about five years ago and decided to donate them to the museum rather than risk seeing them split up. "It is the ideal place to exhibit the engines."
The international marketplace for working scale model aircraft engines put the value at between $8000 and $11,000 each, meaning his 13 engines could be worth up to $143,000.
Mr Janes suspects that few other people in the world would have made as many scale model working aircraft engines in the way he did.
He was now in the process of valuing a lot of his other scale models that included ships and boats, a railway engine, a steam truck and a traction engine, in preparation for selling some on Trade Me.