Vintage Thing No.157 - Vat 69

VAT 69 caught my eye in the car park of our hotel after the 2022 Exeter Trial

The 92nd Exeter Trials people's choice for Spirit of the Event went to Hughie Walker and Angus Frost with their Austin 7 special VAT 69. Their climb up Simms was a tremendous crowd pleaser and finishing one of the wettest Exeters in a machine without roof, doors, sides and windscreens was nothing short of superhuman.

From a distance, VAT 69 could be mistaken for a GN special that had eaten its greens. Through the trees and rain it sounded a bit like a vee twin but those cylinders are at the widest vee possible - 180 degrees. This is an engine whose barrels have fallen out. They dislike each other so much they can't be in the same engine compartment. They are horizontally opposed.

That power bulge down the side is for the driver's feet

I like flat twins. The layout is still relevant today in modern cars for packaging reasons. The term horizontally opposed sounds earnestly belligerent but 180 degree flat twins are actually well balanced engines and just have a slight rocking couple due to the staggered cylinders and crankpins.

The chassis and running gear on VAT 69 is all Austin 7 apart from the engine. The narrowed Austin 7 grille - there is no radiator - recalls the outline of a GN but bears the Austin logo of the winged wheel. The rest of the bodywork consists of a bonnet and side panels, all quickly detachable in case any nosy passers-by want to see the gubbins inside. this happens a lot so VAT 69 is often in a state of undress. There are mudguards and seat pans but VAT 69 enthusiastically embraces the concept of added lightness.

VAT 69 is short for Vintage Australian Transport 1969 in recognition of this Austin 7 being driven to and then round Australia in 1969 by Graham Rankin. Of course, back then there was more Austin 7 about it.

There's not a great deal of storage space in VAT 69

Many years later it fell into the hands of Hughie Walker who saw the benefit of more cubes and fewer cylinders and spark plugs to argue with.

The powerplant is what really grabs the attention. Aero-engined monsters and Austin 7 specials have appeared on Engine Punk for years. I suppose it was only a matter of time before their love child came long.

Originally Hughie fitted a Cleone two stroke flat twin engine and this became an internet sensation backalong among my excitable mates on Youtube. 

Dating from 1930, the 1200cc Cleone engine was not a success in its day. As Hughie told me, "It converted hydrocarbons into noise but not power." 

I can just imagine the two argumentative horizontally opposed pistons trying to kick each other with their conrods and the crankashaft in between gleefully going "Another power stroke! And another power stroke!"

Such a shame - how many flat twin two-strokes do you know?

The only one I can think of is the Velocette Viceroy engine. These 247cc (54 x 54mm) two stroke flat twins powered an ill-fated attempt at a UK scooter and went on to powering hydrofoils later life. 

Without valve gear in the cylinder head, two-stroke flat twins are more compact than four-stroke motors and in a parallel universe I like to think Velocette produced world beating two stroke 250 flat twin world beating motorcycles - but back to this universe which still isn't such a bad place to be.

The engine bay of VAT69 is a triumph of packaging. Much of the engine is outside

Hughie's policy is one of continuous improvement and specifications may change but the current engine is an ABC Scorpion of 1921 vintage. ABC stands for the All British Company. It enjoyed a brief flowering around World War 1 with lusty flat twin engines that powered motorcycles, cars and aeroplanes. The designer was Granville Bradshaw who used overhead valves operated by long pushrods. He was a great flat twin enthusiast and some historians credit him with inspiring the layout of the first BMW flat twins.

The ABC engine mates up to the Austin 7 gearbox

ABC went out of business in 1923 but not before offering the Scorpion engine for the post war interest in lightweight aircraft. Bore and stroke are quoted variously as 87.5 x 91.5mm or 3.6 x 3.7 inches. These dimensions are not quite the same - as Bradshaw worked in inches I reckon the metric equivalent of 91.44 x 93.98mm is more precise. Displacement would then be 1234.3cc instead of 1100.5cc. These things matter to me and there's no substitute for cubes. On a compression ration of 4:1, claimed power output was 30bhp.

Knitting needles of power!

Hughie used parts of an Austin 7 crankcase to mate up engine and transmission. He made a propshaft out of the contents of the Austin 7 torque tube but dispensed with the torque tube to make the prop take the bending loads.

This cylinder head layout might have good swirl for a 1920's design. Electrickery is provided by an alternator from a little Kubota diesel driven by that blue pulley on the flywheel.

He originally intended to go racing with VAT69 but it's natural habitat seems to be in mud. Hughie and Angus had campaigned it on the Lakeland Trial in 2021 and think nothing of driving to Exeter or the Lake District from their home in the midlands.

Lighting and other electrical niceties are cunningly taken care of by a little alternator liberated from a Kubota diesel. This lives on an adjustable pulley with a rubber wheel running off the outside of the flywheel. When Hughie pointed this out, a surprising number of onlookers nodded knowingly. It seems Kubota diesel alternators may be becoming a cult among special builders.

Hughie's most recent innovation was a toolbox under the driver's seat pan. Angus said this increased the footroom for the passenger no end. This still looked even more restricted than the footwell on Brian Partridge's Ridge-Cannon wot I bounced in for the 2016 LET. Angus added that previously he had put his left foot outside and rested it on the 2-into-1 exhaust that ran on his side of the car, keeping him nice and warm despite any draft up his trouser leg.

Hughie and Angus impervious to discomfort. They might even relish it. Watching their triumphal ascent of Simms, I was struck by Angus' laid back approach to bouncing until I realised that he sits so close to Hughie, he has to lean out of the way of Hughie's elbows as he saws away at the wheel.