Project Poland: Quattri-phenia
Ever since riding Chiselspeed’s Quattrini demonstrator, Stan has hankered after his own conversion, and this summer’s ride to Poland provides the perfect excuse.
Since riding Chiselspeed’s Quattrini demonstrator, Stan's hankered after his own conversion. This summer’s ride to Poland provides the perfect excuse
My Casa 185 has been nothing other than reliable and dependable, but that’s never stopped a scooterist wanting more. As a rule, highly tuned engines don’t suit my riding style, but I changed my mind after riding a Quattrini last year. With a very usable 24bhp ‘out of the box’, it brings TS1 performance to small block owners, and as I’ll be riding alongside a TS1, the opportunity to compare them was too good to miss.
On the case
As they’ve made Quattrinis something of a speciality, the rebuild will be conducted by Martin and Russ at Chiselspeed. Our first thoughts were to strip down my engine, but as there’s nothing wrong with it and the extra power would mean fitting an entirely new drive train, it made sense to start with a fresh casing. Martin suggested using a Spanish Li casing. A commonly accepted Lambretta fact is that Spanish engines are beefier than their Italian counterparts. What is certain is that for a limited time, the Spaniards used a single casting for all engine types, machining its mouth to suit the cylinder. As a result, the amount of metal surrounding the Li case transfers is considerable; up to 15mm compared to 7mm on a standard small block. The problem would be finding one, and the obvious place to start was at Buzzsolomoto, the purveyors of all things Spanish.
Obviously, the easiest way to spot one of these casings is to look at the crankcase mouth. Unfortunately, we were faced with a pile of around 100 small block engines in varying stages of decay, and the search needed to be narrowed down. “The Spanish moved to the single casting in 1966,” explained Buzz. “That should mean an engine numbered in the 300,000 series, but that’s no guarantee.”
His point was proved after we’d freed the barrel off an engine in the first 700 of that serial allocation, only to discover it was a standard casting.
“There are a couple of other pointers,” said Buzz. “Because the base gasket is smaller than the crankcase face, it’s sometimes possible to push a feeler gauge between the barrel and crankcase. I’ve also noticed that there tends to be two alternative exhaust mounting blocks cast on the underside.”
Applying these tests, we worked our way through the pile before deciding on an unlikely candidate low in the 700,000 series. Barrel removed, it’s exactly what I was after.
“I’ve never seen that before,” laughed Buzz. “This probably dates from the late 1960s, and by then the supply should have been exhausted. I learn something every day!”
In common with most old Lambretta engines, my mag flange suffered from the usual seized studs, chips and knocks. With Uni Auto’s newly re-made mag housings retailing at under £50, unless for a concourse build, it’s no longer worth welding and re-threading an original. Needless to say, one’s found its way on to my growing pile of components.
Internal organs
The engine’s heart will be the Quattrini kit, but that’s only the start, as it also needs a drive train, which is capable of absorbing the extra power. I like to think we’ve decided on a selection of quality parts that won’t bankrupt me.
Starting at the front, we’re using one of SIP’s recently launched crankshafts. Made in Italy, these come in two grades, Premium (£155) for standard engines and Performance (£230) for tuned motors. Given the Quattrini’s bhp, the Performance version was the obvious choice. Martin advised using the 60x116 combination, as this gives an additional 8cc. It won’t change the world, but as they’re free cc’s, I may as well have them.
Next port of call is the clutch, and with plenty of hills along the route, strength and reliability are critical. I selected BGM’s Superstrong (£377). With six plates and 10 springs in a ready-to-fit cassette, it promises an elegant solution to the age-old problem of burnt-out clutches. Although Chiselspeed’s demonstrator was a revelation, a fifth gear would be useful for touring. Fortunately, there’s no shortage of 5-speed Lambretta gearboxes on the market. The problem is affording one which is strong enough to survive real-world use.
At £495, AF Rayspeed’s Clo5e is something of a bargain, and Rayspeed’s Ben Kemp is keen to prove that the first batch’s selector problems have been fully resolved. A trip to Poland should demonstrate if that’s true.
No aspect of the build has caused so much debate as the carb. Dan’s a fan of Dellorto’s PHBH, believing that at around £90 they’re cheap and relatively frugal on fuel. Martin, however, is convinced that the flat-slide VHSH works best with the Quattrini, although at almost twice the price. Caught between my boss and the engine builder, I turned to Rayspeed, who cast their vote in favour of VHSH.
At £340, Chiselspeed’s CST range aren’t the cheapest exhausts on the market, but these are the only pipes specifically engineered for the Quattrini. I know of one owner who’s now considering his third pipe, after his choices so far have failed to unleash his Quattrini’s full potential. Sometimes it’s better to simply grasp the nettle, so I’ve plumped for the touring CST10. Project Poland updates to follow...
Words & Photographs: Stan