How to build a 45 BHP+ Vespa

Created by Jesco at 14:10 on October 12, 2020

The SIP-BFA 306cc Kit at present is the most powerful engine money can buy. At least it is if its traditional geared scooters are concerned. We’ve proved that, and that this by no means is the end of the road, with our 2019 SIP custom sprint-racer “Something Special”. 

In 2008 the KTM LC4 640, the most iconic endure of its time, in its last incarnation, made 50 HP as measured on the crankshaft. The engine this here is about makes over 50 BHP stock! And it doesn’t live in a sporty MX bike but is meant to go into a traditional Vespa chassis. To give you the accurate number: With its 306cc engine capacity it makes 57 BHP on the crank. 


Racing Cylinder SIP BFA 306

The 306cc SIP-BFA engine at present is the most powerful engine money can buy. Jesco Schmidt and the SIP team proved that, and that this by no means is the end of the road, with the 2019 SIP custom sprint-racer “Something Special”. A whopping 72BHP at the rear wheel was the ultimate result. Enough to win the best of all category in the prestigious German Scooter Sprint Championship. The SIP-BFA 306 is a lot more than “just” extremely fast and powerful. The more we work with this engine the more it demonstrates just how good it is for pretty much anything. Hence 2020 was the year for yet another SIP-BFA based project: A daily driver with touring credentials. The goal was the SIP tour to Corse. The fundament for this was to be the Tuning-kit (Art.-No. 7824521J) with the bits and pieces required for the engine, crankcase, clutch and cylinder kit are not just potentially extremely powerful, they are also extremely high quality. Unfortunately the kit sets you back around 4.700 Euro, which is a bit more than you pay for your “standard” Vespa tuning. The goal was for the engine not only to be to the tour with, but to make it an easy, relaxed and controllable ride. So we decided to live with a mere 45BHP. Which still is ample in a 100kg Vespa. In particular so if that power surfs on a massive wave of torque with the mother of all powerbands. Next port of call was road testing with the TÜV. The scooter needed to be completely road legal for the tour. Hence the TÜV engineer was involved with the project right from the start. Still it took a ton of tests, measurements and reworking and retesting. 

See you later....

All in all building the scooter took some three month. Acceptable considering what it is. The scooter is not only a great touring set of wheels, it also come with uprated suspension and reliable brakes. All this makes it a package that makes asks to be thrashed on the race track. Full marks, not only on the circuit but also on alpine passes and the sandy coastal roads of Corse. We ourselves were so smitten with the whole project that we decided to document the entire build with videos. That’s how the series “How to build a 40Bhp Vespa” ended up on the SIP YouTube channel. To ensure that things did not get too boring between the tour and the building of the engine we decided to cover the entire build of the full scooter. And the tests. And the race on the Nürburgring. And…, well, maybe you should simply go and check it out for yourself. Just one thing maybe: Never, honestly, never! has touring on a Vespa been anywhere near as much fun! Here’s a dyno-graph for the workshop. Or the bedroom.

Here’s the 19-part SIP-BFA Touring engine video project on YouTube! Enjoy. We’re looking forward to your comments!


Playlist "45 BHP+ Vespa Project" on YouTube (19 Episodes)

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Here is a notepad with the parts used for the SIP BFA engine with 45+ HP, have fun browsing!



Jesco is our product manager and technical editor. Many people know him from his videos on SIP Scootershop TV, where he presents tutorials, stories and products.