The Malossi 180/166.....two incarnations of the same item.
I won't go into extensive detail in this article, as most (if not all) of the information that i could write about the tuning and fitament of this kit, is directly comparative to the Malossi 210 article. By that, i mean that they are both bolt on Vespa performance kits, that help the engine rev higher and harder to produce more power than standard, they are both made by Malossi, and they both benefit from additional porting work to the cylinders and engine casings, and the use of extra tuning items such as cranks, carbs, exhausts, flywheels etc to improve overall performance. All of which can be read in the applicable articles.
Never the less, this particular item is for the 125/150 engine Vespa, and not the 200, so it deserves an article of its own. So let's take a look at the kit itself......
Above & Below: The layout of the cylinder ports. Like any good kit, its full of big holes! Oodles of extra transfers, and increased port sizes over a standard cylinder. This is the 180 version of the kit, Malossi have now changed it to 166.....i'll explain why later in the article.
Below: The transfers on the 180 version.....it's not a big bore 200cc cylinder, but at least it does have some decent sized transfer ports (in comparison to a 200cc engine).
The transfer ports on this 180 cylinder also have a lot of metal on them which can be ground back, in order to enlarge the port size.......this will almost certainly help to put a smile on the face of the owner, when compared to a kit that has not had the transfers enlarged.
Side note: It's worth noting that the short-stroke Vespa T5 in standard trim, releases 11bhp, which is the same as the much larger 200cc long-stroke engine. The main reason for this identical power release from the much smaller 125cc engine, was the fact that the 200cc only uses a single small transfer port, at the top of the cylinder. The T5 (as the names suggests) uses a 5 port system, 1 at the top, and 2 each side, and revs higher with its shorter stroke.....thus equaling the power output of the 200cc engine.
Also, Malossi originally released this kit as a 180, but later updated it to a 166.....less cc?? Yes, the reason being, as the size of the cylinder bore decreased, the area that they could use for transfer ports increased! So the recuction in cubic capacity was compensated for by using larger transfer ports. So Malossi had found the 166 kit could give more power than a 180 kit, by reducing the cubic capacity but enlarging the transfer port size.
Lesson....large transfer ports and high revs are always a good idea if you want more power!
Manufacturers also have 'minimum tolerances' that they like to work to, and usually leave a thick sealing edge round the base of the cylinders they make.....in this case, Sean will use the larger 180 kit....but gain the increased port sizes by porting the cylinder and the engine casings.....the best of both worlds......more CC and bigger transfers!
Below: Much like the 210 kit, Malossi hollow out the sides of the piston, where they match up to the transfer ports in the cylinder and casings. This is a method of utilising piston area to increase the transfer port size. It also incorporates boost/inlet port feeder windows at the back of the piston skirt.
Below: Engine casings.....3 ports are already used on this size of engine, but can be ported out to really enlarge the transfer area. These particular casings have been stood for some time, and need cleaning up, porting, matching and polishing to the 180 kit that Sean is fitting.
Below: Sean has just started to grind the metal fropm one of the ports, he will go on to enlarge all 3, match to the cylinder, and then polish and clean up.
Below: A 125 casing that has been prepared for a 166 kit.
Tip: A black coated casing, cylinder or exhaust will dissipate heat slightly better than the same item that is chromed or polished. So if you want your engine to run cooler and have less chance of overheating......black it!
Below: These casings are fully prepared for the kit....this one gets reed-vale inlet, cut and flowed crank, big carb, sterling exhaust....and Mr Brday casing/cylinder porting.
Below: A standard 166 for comaparison to the tuned one, in the next picture, Sean did for a Ripon Club member.
Below: This one is gettig extra attention from Mr Brady.... see how much extra metal has been carved away to improve the gas flow through all the tranfers.
Article Summary:
So the 180/166 kit is a great performance boost for those that already own a PX125/150 Vespa. It is however a bit 'middle of the road' in terms of performance. You don't get the big CC advanatge of a Malossi 210, nor do you get the 5 port transfer system of a T5. But if you do already own a PX125, then it is a good way to boost your performance cheaply. Additional enhancments will help of course, the ususal suspects (as covered in other sections of this site) such as, reed valve, exhausts, lightened flywheel, big carbs etc....but inavariably, a 166 owner could be slightly dissapointed in performnace, when compared to say a 172cc T5 which is only 6cc different. Of course, as explained, the 6cc does not make the difference between these two kits....the transfer ports do. So given the choice of scooters, get a T5 and 172 it, or get a 200 and 210 it (both with proper porting!)......but if you got a good deal on a PX and want more power from it........then get a 166 and some other bits, and you'll be happier with the performance than when compared to standard....and if you go that bit further....like the cylinder porting shown in the above pictures......the performance will certainly put a smile on your face!
Malossi'd-up px125.........
Above & Below: Vespa px125 fitted with Malossi kit, fully ported, Sterling exhust pipe, Sebac shocks, disc brake, and sprayed up in Kawasaki green. Simple, effective, value for money, goes well....and looks good too.
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