VIDEO | Sheer Lunacy
When it comes to original Innocenti scooters, there are two sorts of 1960s models that remain affordable: the Luna line (Vega, Cometa and Lui) and the J-range (J50, Cento, Starstream etc). Despite this, all these scooters carry the same benefits of being ‘historic’ vehicles and therefore, in the UK at least, free from Road Tax and MoT test requirements.
The other great advantage of a historic scooter is that you can currently still ride one into an Ultra Low Emission Zone like the one recently introduced in Birmingham without paying the daily charges that newer bikes will soon have to pay in certain cities.
Why are Js and Lunas cheaper than LI-series?
I’d say for two perfectly valid reasons: firstly the styling is an acquired taste and secondly, the performance of the small capacity engines is very much city-orientated and weak on the open road.
With regards to styling, the Luna is a distinctive 1960s gem styled by Supercar supremo Nuccio Bertone. The J-range wasn’t styled by anyone of note, but as a Cabbage Patch Doll of the Lambretta range, there are folk who still love them. The best description of these people is ‘perverted’.
With regards to performance, all previous bets are off because Casa Performance’s new 135cc kit rewrites the rulebook. This kit makes the Casa 75cc conversion for the 50cc engines look like a joke and even leaves the expensive and complicated 140cc conversions using hard-to-get J125 parts in its wake. Here is a simple bolt-on solution that does the business.
The new Casa 135 kit by Casa Performance is a Nicasil-lined reed-valved alloy barrel kit that is currently undergoing extensive testing in pre-production format. Think of the kit as a mini-TS1 for the upright-barrel 60s engines and you’ll get the idea of what a leap forward it is for these engines.
So far Dean has ridden a fully-loaded Vega with this kit across the Alps from Italy to Germany and back via the Czech Republic.
Currently there is also some discussion about producing a genuine 125cc version of the kit that could be perfectly legal for learner riders in some EU countries.
What do I need to know before we start?
Essentially the J and Luna engines are based on the same platform but with a few different configurations:
- All J and Luna engines have the same base gasket area.
- The 50cc and 75cc engines are based on engines with 44mm stroke crankshafts.
- The 100cc and 125cc J-range engines use a crankshaft with 48mm stroke.
- 3-speed engines use a narrow crankshaft that is 36mm wide at the crankpin.
- 4-speed engines use a slightly wider crankshaft that is 40mm wide at the crankpin
The new Casa 135 kit will fit all types of engines, regardless of their original capacity, as long as a 48mm stroke crankshaft of the correct width for that engine casing is fitted. Currently, the only replica 48mm-stroke cranks available are the 3-speed Cento/J125 type, but conrods are available for all models. The wider, Starstream type cranks are about as easy to find as flip-flops for a python. In testing, Dean managed to destroy the big-end of a Starstream crank assembled with a pattern (PA) rod and bearing within 500 miles. However, another crank fitted with a genuine Innocenti rod and bearing has since proved itself up to the job.
The development scooter is a standard Italian-market Lui (Vega) 75 upgraded with a 4-speed J125 Starstream crank, a modified standard clutch and a larger front sprocket. At the time of testing the Vega was fitted with a modified Lambretta Fresco exhaust, a 25mm Dellorto PHBL carburettor and a prototype Ducati ignition.
The first thing you notice about the Vega – if you’ve never ridden one – is that it weighs less than an anorexic ant so manoeuvring one is a delight even for the fairest of sexes. Despite its diminutive stature, the high bars of a Luna make the ergonomics fine even for 6-footers.
Kick-starting is also much easier than a normal tuned Lambretta despite the addition of a kit. The clutch wasn’t overly heavy despite being fitted with 4 thin LI-series plates and 200cc type springs.
The oversized 16-tooth Casa Performance front sprocket does make for a fairly tall first gear, but the Casa 135 is very much intended as a road kit in standard format. There is plenty of torque available to pull away without having to slip the clutch too much, even with the lightweight flywheel.
Despite the wide-spaced gearbox ratios the Vega gets up to speed faster than a standard GP200. In the configuration I rode, power output was around 14hp which is sufficient for a top speed in excess of 70mph by GPS.
With relatively mild port timings of 120-degrees transfer and 178-degrees exhaust there’s plenty of potential to get more out of the kit, but doing so feels like you would lose practicality. In the current format the Vega suddenly becomes a viable vehicle for riding 2-up (if you have the long seat fitted). It’ll even return 10 miles (16km) per litre of fuel at 60mph giving a tank range of around about 50-miles.
Overall you should expect similar performance from a kitted J-range which is only slightly wider and heavier than a Vega. The lads at RLC have found that a 15T front sprocket is better suited to their dimensions. That should slightly reduce top speed compared to a Luna, but improve acceleration.
The limitation for riding 2-up was that my passenger had to keep her feet away from the hot exhaust downpipe.
Any other issues?
The only significant issue to report is one that plagues all Lunas: vibration. Essentially the Vega has quite small engine silent blocks which inevitably transmit more vibration than a J-range with its bigger rubber mounts. Add to that a crankshaft from a standard J125 with a balancing factor that is ‘totally wrong’ according to the Casa Performance boys and what you get is a machine that rides perfectly smoothly at 55mph, but vibrates progressively more as the engine rpm rise towards peak power. Without gloves the bars have a definite tingle, but with thick gloves on it’s not overly intrusive.
The solution to this should be the correctly balanced custom-built crankshafts which Micky and Lorenzo from Casa Performance are busy working on. Once solved, there really will be nothing significant to moan about.
The prototype Ducati electronic ignition features a 90W power output. That’s enough for bright 12V lighting at little more than tick-over; however, you could still run this engine on points or even convert the original ignition to electronic with one of Anthony Tambs external pick-up conversions.
In order to fit this kit to either a J-range or Luna the only modification required will be to trim the rear mudguard to allow clearance for the 90-degree inlet manifold.
The only remaining issues to tackle result from massively increasing the performance of machines originally conceived as little more than mopeds. The test machine was upgraded from the standard 3-stud hubs to Indian SIL Sunny 4-stud versions which accept Lambretta 10-inch wheels (tubed or tubeless). Sadly these aren’t easy to find so again it’s another product that Casa Performance are looking to manufacture. That said; original Luna brakes are famously good even in standard form.
With regards to suspension, the front forks were fitted with an RLC damper conversion kit while the rear was upgraded with a modified BGM Lambretta shock. Both make a massive improvement to the normal bouncy ride of a Luna.
The Casa 135 kit in detail
The prototype kits are currently in rapid prototype aluminium castings which have been Nicasil plated.
The port layout is fairly conventional with four transfer ports fed from the two crankcase openings. These are made small enough at the gasket face to match a standard casing, but they may easily be enlarged to improve flow into the transfer ports.
The single exhaust port is conventional ‘letterbox’ layout, but sensibly they’ve added two extra exhaust studs (an old Ancillotti trick and more recently seen on BGM kits) which allows for 4-point fastening on exhausts with a dedicated flange, or for conventional fixing of any normal J or Vega 2-stud exhaust, as not everyone wants an expansion chamber.
The interesting change from standard is the reedvalve inlet which uses a Derbi Senda reedblock and feeds into the barrel via a large port divided into three by two large vertical bridges. These bridges support the piston skirt much better than a single port opening with the idea of increasing reliability and piston life. The centre of the 3 inlet openings extends upwards to form a rear boost transfer port.
The piston chosen is a dedicated Meteor cast piston for this kit based on that of a Piaggio 125cc automatic intended to maximise reliability.
The cylinder head also follows current convention by recessing the gasket face so that the combustion chamber drops slightly into the bore to self-centralise the head.
Given that this kit is a first prototype fitted with a cobbled-together exhaust based on a 1980s pipe, it performs amazingly well. There is definitely more power to come with a dedicated expansion chamber but to be honest, it’s not needed. Even with a Fresco this kit is a game-changer for the J-range and Luna machines.
At the moment Casa Performance are still finalising the kit specifications so it is too early to give a final price or release date for the kit. Beyond the kit itself Casa are also working on 5-speed gearboxes as well as other transmission upgrades. As with the actual Casa 135 kit itself, the Ducati electronic kit for the Luna/J-range is also expected during 2019.
If you have a J or a Luna then this kit is going to add value to it even if you don’t fit one. For those who’d like one of these scooters then now’s probably the best time to buy. From next Summer onwards these machines are about to become much more viable for every sort of scootering.
Text & images: Sticky
Additional photos: Dean Orton
Casa Performance Luna 135 kit gallery
New products always in development…