Tuning topics

For some time now Crayford Auto Developments in Kent have been involved in marketing a new breed of vehicle to this country—the amphibious four-, six- or even eight-wheeled all-terrain (ATV) machines. Recently Crayford formed an offshoot of the main company called ATV Ltd. at 1 Godstone Road, Oxted, Surrey, to deal with the “go-anywhere” type vehicles, which are manufactured mainly in Canada for an enormous recreational market in that commonwealth country, and in the United States.

The general principles behind these vehicles are similar in most cases, such as all chain drive to split axles via a centrifugal clutch. Fat BF Goodrich tyres, which act as paddles on water and as chunkies on land, are inflated to 1 1/2 to 2 lb. per sq. in., their ample proportions and low inflation pressures letting the rubberwear act as a very effective suspension medium over rough ground.

We tried ATVs with both two- and four-cycle engines, all giving less than 20 b.h.p. All but one of the ATVs that we tried had twin-lever steering, a rearward pull actuating one side of the vehicle’s brakes, thus forcing it to turn very sharply if required, The most popular model, the Amphicat, with manually engaged centrifugal clutch and 12 b.h.p., costs £895 (£10 less without an electric starter), but by selecting the 20-b.h.p., 45 m.p.h. “racing” engined model the customer can push the price to £995: an eight-wheeled Argocat would cost comfortably over £1,000.

Being rather more specific, we were able to try the four-wheel Got’cha and six-wheeled Scrambler, made by Action-Age, the eight-wheeled Argocat by Argo, and the the popular Amphicat by Beehoo (yes, realty!) Industries near Montreal. We also watched whilst Crayford’s own Polecat four-wheeler, with unique swivel-action body for covering rocky terrain and jet propulsion for water travel, was put through its paces on the comparatively huge wheels it utilises from a Land Rover.

Even the biggest eight-wheeled ATV is only about half the size of a Sprite, vacuum-formed Cycolac bodies helping to keep the weight down and shattering strength up, compared to glass-fibre. At first we found our progress was very jerky, tending to always apply too much braking effort at low speed. However, a 20-min. session with the Argocat had us feeling confident enough to tackle our host’s steep and slippery test track without getting stuck. We also enjoyed our spell with the Scrambler, which differed from the rest of the test vehicles in having a steering wheel, connected up to an hydraulic braking system, and acting in the usual ATV manner. However, the most impressive choice in terms of cost and effectiveness is probably the Amphicat, which skims over the ground at an impressive rate and offers very precise directional control by means of the usual twin levers, which are pushed forward individually to engage drive, and pulled back through neutral to apply left- or right-hand side braking. The hand throttle gets in the way a bit when one is learning to drive the vehicle, and a foot control would probably be better for most users. Judging the ATV breed as a whole, we found that the most impressive facet of their character is their behaviour over wet, uphill twists, where they will squirm up seemingly impossible gradients and still respond to the braking control levers with halting.

…And from the same team, an Alpina BMW 2800

The Crayford side of the business is much as it ever was, being primarily occupied with bodywork conversion (Mercedes estates, Cortina convertibles and r.h.d. Porsche 914s), but we were invited to go for a ride in a BMW 2800 saloon which had just been built up by the firm, using the Alpina parts for which they are the sole UK concessionaires. One of the Crayford directors, David McMullan, owned four BMW saloons in a row (he’s currently using a Mercedes, but one gets the impression it’s very much a stop-gap), and it was this period of ownership that made him consider marketing the Alpina parts in this country.

McMullan commented that he couldn’t recall selling any Alpina BMW derivative to anyone under the age of 40, and so they had ensured that the Weber carburetter jet settings were altered from Alpina’s rather rorty settings to give a flexible fuel delivery throughout the engine r.p.m. range. The Alpina part of the business is a new departure from Crayford’s normal policy, as the German parts do invalidate the maker’s guarantee in this country (though not in Europe we gather), and thus the firm deal direct with the public, should there be any problems. Most customers have the Alpina modifications done when the car is new, and usually one car a month is completed, racing bits being supplied only to order.

The car we passengered in would cost about £500 over the normal list price. For that sum of money the engine is modified to give an extra 50 b.h.p. or so at the rear wheels, the new suspension coil springs give a 1 1/4 in. lower ride height, scoops are fitted to the bonnet and the whole job topped off with a coachwork bodyline. Power unit modifications consist of triple Weber 45 DCOE carburetters, converted manifolding culminating in a new twin-pipe exhaust, a 300 deg. Alpina camshaft, cylinder head inlet ports have the “flute” gas splitting channel removed, 0.4 mm. is removed from the head face and the pistons need notches machined into them to clear the Alpina valves, the latter boasting special springs to allow the regular use of 7,000 r.p.m. from the straight six engine. Incidentally the exhaust system on r.h.d. cars is not as good as those installed for I.h.d., and customers who want the ultimate would have to specify the left-hand steering layout.

In action the car appeared to be extremely impressive, pulling away cleanly from less than 1,000 r.p.m. in top gear and even running without snatch on a 500 r.p.m. tickover in top! Running briefly up to 5,000 revs. in the lower gears provides phenomenal acceleration, accompanied by a hearty note from the exhaust. The suspension modifications seem to remove a little lean while the ride is still very comfortable. The only snag we could see was the spitting back from the carburetters when the engine is cold: there is no choke, and with that bank of carburetters it is unlikely that one would ever need one, so the procedure is to run the car for a while before setting off from a cold start.

Crayford Auto Developments Ltd., live at High Street, Westerham, Kent, and any interested readers should contact them at that address.

J. W.