Questions regarding LE dimensions
Is the Mk.11Velocette LE an overbore of the earlier engine? Are the later dimensions shared across the LE range, including the Valiant, but I guess not the Viceroy? And is this why my dad's late 1950s LE used to blow cylinder head gaskets?
As a matter of course, he always carried two spare gaskets and a bottle of water in a pannier!
Ray Lardner, email.
'Yes' is the simple answer to both questions, Ray.
The water-cooled, side-valve transverse flat twin engine of the first (Mid) Velocette LE had the bore and stroke dimensions of 44x49mm, giving 149cc. This engine, with 7:1 compression ratio, gave 6bhp at 5000rpm.
For the 1951 season, the Hall Green, Birmingham, maker opened out the bore of the LE engine by 6mm, to give dimensions of 50x49mm and 192cc. This engine, with its 7.25:1 compression ratio, delivered Bbhp at5000rpm.
The Vogue, with its allenclosing glassfibre bodywork, shared the LE's water-cooled engine, but the Valiant, while having similarities with the
LE - using shaft drive, front fork and flat twin design - was a very different machine. It comprised of an ohv air-cooled flat twin engine with 7.25:1 compression ratio and the Mk.II onwards LE's bore and stroke dimensions, housed in a tubular, full loop frame.
It developed 12bhp at 7000rpm, with top speed usually quoted as 68- 70mph, with the faired Veeline slightly faster, but, also, at 270lbs, slightly heavier.
As you imply, Ray, the Viceroy scooter was different again. Despite slow sales, it was a cut above most rival scooters and had them beaten for speed, performance through the gears, roadholding and braking but the (predominantly) Italian scooters were, in the eyes of the young, sexier, and, as we know, this feature sells.
The Viceroy's 54x54mm 247cc transverse flat twin two-stroke engine developed 16bhp at 5000rpm giving the heavy-ish (302lbs) fully enclosed scooter a top speed of well over 60mph. Introduced for 1960, production ended in 1963, before which a few 300cc versions were made.