MB RT 200 Race engine


RT CYLINDERS A TUNERS WET DREAM!

Well not quiet but if we all had them in the 80's and 90's when we were all mass tuning we would have saved hundreds of hours of tuning time and saved time in setting them up as they are so easy to do! Here we have one of our old French customers who returns every now and again. Gilles put me up and entertained me for a night on the way to the Euro in Spain.

I've featured him with an old UK group 6 engine he bought which won the UK championship in the 90's and I rebuilt the top end for him. I've featured him with modifying a race pipe to stop it grinding and I've featured him in some racing shots as he's so photogenic! Because of these features our oil supplier has sponsored him for when he's racing. I believe I've also tuned another road engine for him and he's also had one of the first RT190 kits years ago. Last year Gilles and his race team did a 10 hour endurance race at Magny-Cours in France, with 27 teams from all over Europe. Leading up to the race I gave Gilles some Tech-Tips on how I thought an engine should be made for a long distance race. In the end his 4 man team over ruled me and started with a Mugello 200 which only last some time before blowing up (don't shoot the messenger) so the team swapped Gilles road going RT190 that he commutes around Paris on. From memory it competed around 8 hours non stop without a problem and in the end with an engine swap came home 11th behind some very professional race teams with full tuned small and large framed Vespas.

This time Gilles has ordered another RT kit for the main engine as all the team were so impressed with this little touring engine! So here it is, I've miss matched some left over sample parts I've had whilst tweaking the RT kits ready for production supply in June. This motor is using a 60mm crank to lift cc to 200cc, I've tweaked the transfers and exhaust port to suit the crank and the race it's going to do. The Inlet manifold is bolted and match through into the standard inlet port and the manifold has a little MB mod usually saved for slotted inlet manifolds that never hold their positioning every time the inlet is undone, check out the dowel. This year they're using a 28mm Dellorto aiming at good fuel economy, part of the advice I gave and last year and part of the reason they did so well in catching up from the blown motor....... the further you go on a tank of fuel without stopping the better, a bit like doing the coast to coast race. For every stop it's got to be 5 minutes that's some distance when your flat out and some catching up! So back to the title! With all the tuning and matching and head compression checks this took around 2 hours. One big advantages of the RT kit, is I designed the transfer feeds to old type stage 6 and the simple idea I built into the design was anyone with a Dremil or drill can easily tune the standard feeds to a full race tune if your casing is already done...... simple and easy look at the photo of the standard RT vs a tuned RT. Bare in mind a full race tune to old Skool iron stage 5 or 6 could have taken 10 hours! Oh I wish I had my RT kits when I was grinding out all those 100's of cast iron cylinders! And then there's all the other advantages which the RT kit offers! Before you ask delivery is confirmed for the middle of June so I'm sorry none for this years Euro in France unless your lucky and I've the odd cylinder to put together. Lets hope Gilles has the same luck with this engine as he did with his RT road engine and you never know it maybe an excuse to drive through France on a tour.

If you want to read about the RT kits click here.


Gilles Fravel on one of his race bikes


Gilles waiting to race


Such a poser


This was one of his race exhausts I had to modify to get better ground clearance


This took ages to modify, it would have been quicker to make a newer one


Set up on half a frame as a jig


Carbon silencer on the other side


Inlet manifold bolted and flowed


Clean flowing


Ported inlet port


Set up on one of our timing jigs


Exhaust flowed and tuned


Tuned RT transfer feeds on the left and standard RT on the right


Flowed inlet port on the left and standard RT on the right


Flowed on the left, standard on the right


Note the little hole to pin the inlet manifold in perfect position


Oval port for long distance touring


Transfers marked out and tuned to suit the 60mm crank


SIL head modified, note the compression sheet all filled out

Mark Broadhust 3.5.2013 Any questions please email Mark on mark@mbseriousoutdoors.co.uk