History of the NOVA-1
by Roger J Schroeder
A Nova is an astronomical event, larger than life, a liquid fueled rocket that is larger than life, and a model diesel engine that is larger than life. This article is about the engine and the efforts of the Motor Boys to reproduce it.
The Nova 1 has a displacement of 4.5 cc (0.275 cu in) and was designed by a Dutchman named I. J. v. Leeuwon in 1943. His plans and a short history of the engine appeared in the Dutch model magazine "De Modelbouwer (The Model Builder) which continued to be published during the German occupation of World War II. As such, they were the first drawings of an auto-ignition engine to be published in Holland. Figure 1 is a copy of the drawings. We are indebted to Ron Chernich for finding the Nova drawings and history.
Piet de Klerk Jr. writing about the Nova in the May 1946 issue of the English magazine, "Model Aircraft" pointed out that during the German occupation, the Dutch modelers could not obtain petrol engines and thus turned to building their own. The Swiss had developed a compression ignition model engine, the Dyno 1, in 1941 and word of its existence spread among model builders. In December of 1943 I. J. v. Leeuwen designed and constructed his own compression ignition engine and called it Nova 1. He later followed it with a design called the Nelri of 5 cc capacity. It is assumed that other Dutch modelers built Leeuwen designs. The Nova drawing also appeared in the 1946 issue of Model Aircraft.
According to de Klerk, the fuel for the Nova is mixed as follows:
24 parts of petrol
24 parts of paraffin
27 parts of turpentine
15 parts of motor lubricating oil (SAE 70), and
13 parts of sulphuric-ether
This adds up to be 103 parts. I suspect that a pinch of bat wings would complete the formula.
De Modelbouwer is still published 10 times a year in Holland by the Nederlandse Vereniging van Modelbouwers (Dutch Model Engineers Society). However, the issue containing the nova is not in the magazineís existing archives, possibly because De Modelbouwer was under the control of the Nazis when the Nova drawings were published. The copy of the drawings came from a private collector. They have a web page and their e-mail address is : firstname.lastname@example.org
After looking at the historical information, some of the Motor Boys indicated an interest in building a reproduction of the Nova. Ron Chernich made detailed drawings with both English and metric dimensions. Don McClusky made the aluminum castings and carved 14 Ĺ " diameter hard wood props like the one shown in Figure 1. Bert Strigler built the brass tanks and valve bodies, and I built the cylinder heads, compression adjustment screws, and the needle valves. George Aldrich helped fit the pistons and cylinders.
Bert, Don, Ron and I have finished our Novas. Ron was delayed until this spring (of 1999) because his job required him to be away from his home and shop for about a year. My Nova is shown in Figure 2. A few years prior to the Motor Boys efforts, Ken Croft, the talented English engine builder, completed a Nova. His engine is pictured in color on the back of the Strictly I.C. issues for Dec. 1990 / Jan 1991 and for Aug / Sept. 1991.
The Nova is not an easy engine to build. First of all, it is big. It measures about 5 3/8 inches from top to bottom. It is the largest .27 cu in engine I have seen. Figure 3 shows my Nova with an Ohlsson 23 perched alongside.
The cylinder is a particular challenge. You start with a 1 Ĺ in dia. steel round about 2 3/8 in. long and machine most of it away. Bert saved the resulting pile of chips and provided Figure 4. We tried to think of short cuts like brazing on the fins and flanges, but it did not appear practical. Believe me, I held my breath during the later cuts and checked every set-up 2 or 3 times for fear that I would ruin the cylinder. Ron did have to start over on his. He will not discuss what went wrong.
All the Novas run. Bertís is shown in Figure 5 during the break-in. I saw 6000 rpm on mine swinging Donís prop. Don and Ron have had running demonstrations for interested groups.