Editors note: In the age-old British tradition of building specials from available components Richard Scaldwell put together this remarkable GN Cycle Car over fifteen years ago. It has been a crowd-pleaser at VSCC and other events ever since. The GN was the forerunner of the well-known Frazer Nash. Most of the photos in this post are courtesy of Stefan Marjoram, who took these images on a journey from England to France this past summer. Also on the trip was the 1905 Darracq 200 HP Land Speed Record Car of Mark Walker covered here earlier, and Duncan Pittaway’s Curtiss OX5 V8-powered Monarch.



JAP V8-powered GN Cycle Car – 200 HP 1905 Darracq – 1913 Monarch.

By Richard Scaldwell: My GN JAP is constructed around the rebuilt remains of what was originally a belt drive pre-World War I GN V-twin using only original parts and technology which were available in period. Now upgraded to four-speed dog clutch-shifted chain drive like the post war cars; it does however retain a wooden chassis, GN clutch and tiny rear wheel brakes.

What many people find to be the most amazing part of the car is the air cooled V8 JAP engine. It was built towards the end of 1908 as JAP decided to build a range of engines aimed at the budding aeroplane industry. The firm already had a very good knowledge of building engines for motorcycles and industry. John A. Prestwich’s keen interest in early flight made this a perfectly reasonable next step, and both V8 and V4 engines were constructed.



1908 JAP 305 c.i. (5 litre) V8.

The engine in the GN is one of four known surviving overhead valve JAP V8 engines and is in fact the prototype V8 which was re-acquired by the factory at some point to be kept on display along with a small collection of their most innovative and interesting projects. This collection of engines was still on display after the demise of JAP and their acquisition by Villiers Engineering, and subsequently fell into private hands after the closure of that manufacturer.

As for the others, the Shuttleworth collection has an overhead valve V8, which powered the famous Willows Dirigible airship on its 1910 flight from Bristol to London. The London Science Museum has the JAP monoplane with its side-valve V8 and a partially sectioned overhead valve V8. The Belfast Aero Museum has one in a replica of the first Fergusson flying machine.

The car as it exists today still runs tiny 400 x 19 inch wheels and tires, but weighs only 1039 pounds (470Kg) complete, so with the lazy 305 c.i. (5 litre) low-compression engine running quite happily up to 2500 rpm with the high gearing, the performance is quite remarkable.

We have regularly used the car for road trips to the south of France, but have also raced and hill climbed with great success; 37 seconds at Shelsley Walsh is quick by any standards! But the great thing about this car, and one of the greatest pleasures, is the ability to drive to and from events and still be very competitive.

Although the original multi-jet JAP carburetor has now been changed to a twin-choke Zenith made for an early Curtiss V8, the engine is almost entirely original and is an extraordinary work of engineering of the period. The original flat-plane crank is one piece and drilled right through the journals and runs in five babbitt (white metal) main bearing shells. The side-by-side one piece rods (more like a racing motorcycle or a GP Bugatti) are assembled by threading them along the crank. Next the big end ball bearings are pressed through the opposite rod into split-ball races which are machined and pinned onto the journals.

The attention to detail and weight saving of the crankshaft present an amazing work of industrial art, but it also makes it extremely delicate and spindly, seeming as much like a beautiful flute as a crank shaft. As it is now well over 100 years old, I have elected to admire it on my library shelf. It has been replaced with a new crank, so as to ensure the safe preservation of the engine in its current competitive life.

Driving the car is of course, like any good GN, an experience to be savored, more like a powerful motorcycle than a car. It is extremely responsive to the throttle and all cornering is conducted sideways because of the solid rear axle, drifting beautifully as it was designed to do. It looks a handful but is really a delightful predictable pussycat!

When I first put the car together in the late 1990s it still had its open auxiliary exhaust ports drilled in the cylinder barrels, so the complete chaos of oil, smoke and flame was quite hilarious. Many period flying magazines had letters from young pilots acclaiming the marvelous engine, but bemoaning the impossibility of flying for more than about 20 minutes. By that time, the oil soaking they received in the propellor wash forced them to descend and mop themselves down! To address the problem and pass modern pre-race inspection, small copper bands now close the drilled barrels and a nice period JAP oil pump is used to run a dry sump lubrication system.

One of the main reasons why the engine is so lovely to look at is the fact that everything, you’d expect to be inside, is actually outside on display. The camshaft is completely exposed (in the vee) with its lever type followers and pushrods. The cam, the rockers and the timing gears are oiled with an oil can before running and seem to be surviving amazingly well. No discernible wear is showing after the many thousands of miles exposed to the road dirt and rain. A quick oil squirt is always entertaining to the inevitable audience that the car attracts…… I like to allow my beautiful wife to do this while I watch the amazement on the faces around!

I made the body loosely based on the first few GN racers which Ron and Archie Nash built in their youth. It has the flavor and feel of these cars, but you can’t tell exactly which one! It certainly captures the excitement of the great cycle cars of the period.

For those of you who have asked, you can watch a short video of Richard running the car up the Prescott Hill Climb during the 2010 La Vie en Bleu event below. The video is courtesy of razorlight.