This is the final report about our pre-Xmas dyno shootout! The 29.9 hp at the rear wheel of a Cast Polini 133 cylinder kit with 54mm bgm crankshaft, Keihin PWK35AS carb and Fire Magic exhaust had to be bettered. With 29.3 hp Jonas did very well, but missed the goal. Followed by Mathias with 29.2 hp […]
Here is the evaluation of our P4 duel. The target was to beat the 29,9 HP mark. Set from a gray cast iron Polini 133 with 54 mm bgm crankshaft, carburetor Keihin PWK35AS and fire magic exhaust. With 29,3PS, Jonas just missed the mark. Close behind with 29,2HP is Matthias with his 133 Polini rotary valve engine. In mutual agreement we have, [...]
On Friday, December 14.12th was the first day of our X-Mas duel. Despite sub-zero temperatures, some performance seekers came to our test bench. Hot coffee with a shot and warm pretzels were available in our workshop as a refreshment. As an introduction, we would like to introduce you to the engine that needs to be beaten - So the duel class, Vespa [...]
From now on all bgm Super Strong clutches are equipped with our new bgm Pro clutch springs. Of course our bgm Pro XL springs also fit in all other Cosa clutches from Piaggio, MMW and Newfren. The springs are made in Germany from the material Oteva70 ®, a material which is specially designed for high […]
From now on all bgm Superstrong clutches will be equipped with our new bgm Pro clutch springs. Of course, the bgm Pro XL springs also fit into all common Cosa clutches from Piaggio, MMW and Newfren. The springs are made in Germany from the material Oteva70®, a material that is specially designed for high dynamic loads, blocking resistance and high frequencies. [...]
Good tools bring even more fun to the workshop. Jobs aren't a mess anymore and can be done properly. Our bgm Multitool bgm8819 contains bgm8811 and bgm8812. The bgm8811 tool is the flywheel extractor (M28x1) for all Vespa scooters with electronic ignitions. Starting at the OEM PX flywheels to the electronic conversion for the Vespa […]
Good tools are fun when screwing. Or better, that makes screwing even more fun. Our bgm multitool tool bgm8819 consists of bgm8811 and bgm8812. The bgm8811 is a flywheel puller (M28x1) for all Vespa with electronic ignition, including our ignitions for converting the Vespa Sprint / VBB and V50 / Primavera and clutch puller for the Vespa Smallframe Models in one. [...]
Our test engine is running, we let it warm up properly. The jetting seems to be right with idle jet 48/160, air correcter jet of 160, atomizer BE3 and main of 140. So now we will see how powerful this engine is. First of all the gear ratio needs to be measured. We measure this […]
Our test engine ran warm and the spraying with a secondary nozzle 48/160, air correction nozzle 160, mixing tube BE3 and a main nozzle of 140 seems to work for now. Now we can do the first runs to measure performance. To do this, the overall ratio in 3rd gear is measured 2-3 times on the P4. In our case, there is a consistent overall translation [...]
Only a few steps left untill we can dyno test our new engine. The engine will go into the Silver Fern and be tested for Rally going and daily commuting then. While fitting the flywheel care must be taken that the slot in the flywheel cone aligns with the woodruf key. Afterwards the flywheel nut […]
Only a few more steps separate us from hooking the engine into a test vehicle. As a test victim for our Polini engine, we use the well-known Silver Fern. When assembling the pole wheel, make sure that the groove hits the crescent wedge exactly. Then the flywheel nut is tightened to 65Nm. Don't forget the washer! The rear brake drum [...]
Today we found the time to have a look at the port timings of the Polini kit. With a 1mm base gasket one look at the degree disc shows us transfer port timings of 125° and exhaust timing of 172°. This results in a blow down timing of 23.5°. Figures that really worth to try […]
Now it starts with measuring the timing and the final steps before the first test bench runs. With a 1mm cylinder base gasket, the degree disc tells us an overflow angle of 125 ° and an outlet angle of 172 °. Values with which you should definitely try a few times. We also try 3 different cylinder heads directly [...]
With appearance of the Polini Evolution cylinder kits at the scene, the cast iron barrels got updated as well. From then on the Polini cast iron barrel is labeled as Polini 133cc Racing. The most innovative feature is the new Polini 133 Racing cylinder head. A massive head with enlarged cooling fin area, CNC machined […]
With the appearance of the new Polini Evolution cylinder, the well-known Polini gray cast iron cylinder has also received an upgrade and from now on has the addition “Racing” in the name. A really massive cylinder head with an enlarged cooling surface, CNC machined combustion chamber and a copper gasket. Due to the greatly increased material thickness and the use of a head gasket as in the Evolution [...]
The carburetor and intake area are prepared. Now we can fill the engine with the parts we still need. The 4 speed levels are built in in the form of a Px200 gearbox. Shift cross and gear wheels are mounted accordingly. The switch cross should be inserted with a little screw lock. Gear wheels, circlips and shoulder rings can then be draped to create a pretty overall picture. The game […]
Carb and rotary valve inlet are prepared and ready! Now the bare casings can be filled up with all the internals that make a good engine. For the gear box we opted for a complete P200 gearbox with layshaft, pre-assembled and in Original Equipment Manufacturer quality. Not a good idea to cut corners here. Because […]
Today we took a closer look at the Air intake filter / bellmouth from Polini as well as for the Dellorto SI 26 carb. And we will answer the question what the glory hole on top of the carb is good for? In the end it has a good effect on the working of the […]
We also take a closer look at the Polini intake trumpet and the Dellorto SI 26. Why do you even need this funnel? In the end, it simply helps the carburetor to suck in more air and to ensure a better filling with fresh gases. More ignitable fresh gases in the cylinder ensure more available power. A larger volume of air must of course [...]
