Scooterotica

Been having a play with Runner engines recently and thought I'd have a go at a barrel. This is what we came up with:
Modified Malossi barrel, 66mm DT175 piston, iron liner, 55 stroke crank, Rotax Power valve, GT reed valve and manifold. These are the first 2, there is a 3rd to follow. The Runner engine mount linkage has to be modified to clear the power valve. The plan is to make a barrel with a wide power band so it can be ridden effectively round town, without being WOT everywhere, yet have extra power on tap for fast motorways etc.

Machining steps






Inserts offered up


First welding opt, assembled, no liner yet. Boost ports and port finishing will be done when the liner is put in.

wow, keep us updated & are you doing any air cooled

Hi,some nice work there Rich,what sort of power are you expecting from this set up?

Dean

Hi rich what sort of out put are you looking at and will the crank need modding at all ? I like the look of these and would Go great on my series 5 auto lammy if you need a guinea pig let me know as I'm from Birmingham too :anbrgin; what sort of price are they going to cost ? Also will you need to make a blanking plate for the reed on the case???

Currently two of the engines are using 55 stroke cranks and one 52 stroke the the ports will be adjusted accordingly. I hope to achieve circa 25bhp @ 7krpm with the valve closed and this shoulf rise to circa 33bhp @ 9krpm with the valve open. This is effectively a flat-ish torque curve from 7-9krpm or there abouts.

The idea is that the transmission locks out at circa 6.5krpm and with a gear up kit it should hit 70 before the valve opens. Once the valve opens and the power rises I hope there is enough revs and power to punch it over the ton but we'll have to see.

The basic principle behind it is we will not be adjusting the transmission to work around the cylinders peak power. The plan is for the transmission to effectively lock out to give the effect of riding a fixed gear scooter with a very broad power band. Why is this an interesting prospect? Well, you wouldn't have to ride like a hooligan in town on WOT, burning up the transmission, when it comes to motorways to can pin it open and it'll fly and on the twisties it won't be a twitchy.

It is an experiment at the moment so we'll see how it goes. There are options to run with Zeeltronic ignitions and RS125 solenoid power valves but the test pilots budget couldn't stretch that far. If it works out and there is a good market I could produce it but that is way in future. To make a 5-10off short run of fabricated barrels like these you'd be looking at circa £800 each and that wouldn't include the donor.

are any of the above for sale rich?

At the moment these are all taken, but if it changes I'll let you know.

very nice

Rich_T wrote:Been having a play with Runner engines recently and thought I'd have a go at a barrel. This is what we came up with:
Modified Malossi barrel, 66mm DT175 piston, iron liner, 55 stroke crank, Rotax Power valve, GT reed valve and manifold. These are the first 2, there is a 3rd to follow. The Runner engine mount linkage has to be modified to clear the power valve. The plan is to make a barrel with a wide power band so it can be ridden effectively round town, without being WOT everywhere, yet have extra power on tap for fast motorways etc.

Machining steps






Inserts offered up


First welding opt, assembled, no liner yet. Boost ports and port finishing will be done when the liner is put in.

that is brilliant work !! , could the powervalve be fitted to a monza or ts1 barrel ?

I saw a similar PV to this fitted to a cylinder MB did. Not sure if it was from a larger form of cylinder like Bombardier or SeaDoo. There are several problems, firstly the close proximity of the plastic parts to the exhaust and secondly the valve removes alot of fin cooling area in the place it is most needed (directly above the exhaust). This is why it is done on a water cooled cylinder.

We are discussing the possibilities to supply the PV machined part as a piece for tuners to weld in by themselves or to build a moster group 6 engine. I suspect that the group 6 engine might come around once this Gilera project has finished and fuel injection is done.