You wanna go racing???
After a brief conversation, the idea was born....Sean would sponsor me for all of the engine tuning, scooter painting and building, and i would find and fund the parts. It was a simple idea, and we vowed to keep it to a budget, which is no easy task when you are building a road going scoot....never mind a race machine! Its a cross between accepting that i've never done this before, so need to take a financial reality check before i spunk thousands of pounds on something that i might be no good at.....but conversely,....wanting to be remotely copmpetative, so that i dont look a proper idiot on the worlds slowest race scooter!
So we have to compromise and economise wherever possible, i already have a 'chunk of change' tied up in my 'dream scoot' that Sean is currently building, so this project has to stick to budget. To that effect, we have used parts which may be less than 100% ideal for the purpose (example a 34mm dellorto when we wanted a 38mm Dellorto or a Mikuni carb) but we are commited to using the parts we had available, and could afford, rather than the 'dream shopping list'. Still, even with these restrictions in mind, we hope to be somewhat competative, well......as best a novice can be.
This whole deal was put into perspective, when i recently talked to a very well known scooter racer, and he let on that he spent £15k on his machine alone, during the last year that he raced!!! I told him that i hoped to hit the track on a £1500 machine, with £500 worth or spare parts as back-up! Two grand to me was a big stretch, but to him.....it was a 10th of his overall budget for the season!!
Spec we are aiming for:
Scoot chassis spec: Li150 frame, cut-down for group 6, no leggies or side panels, drop bars with quick-action throttle, small petrol tank, TT91 tyres, GP200 forks, Taffspeed rear shock, anti-dive front disc brake, sebac shockers.
Anyway.....this is how it goes......
(Click on images to enlarge)
Below: I met a nice chap called Ken via the LCGB website, and purchased this ratty old Li.....the basis for the project!!!
Below: Within 24hrs it was stripped bare and cut to pieces!
Below: Bodywork prep was started, bits cut off, grinded down, sanded off, welded in....and filled!
Below: Matt black it!! Cheap, cheerful....and kinda mean lookin! :O)
Below: LD tank added, not sure if it will hold enough juice for this thirsty beast.....but we will soon find out!
Below: Beedspeed Vespa drops, converted using bits from the old Li headset, and then stripped of non-essentials, polished up and fitted. Looks good to me!
Below: We often discussed going fast, but we also discussed slowing down and stopping, and figured an anti-dive kit was the way forward. Big thanks to Martin from www.justlambretta.com for sorting an excellent price on this and the Dunlop tyres.
Below: Dunlops sitting on red and chrome.....bling baby! Those sticky muthas should help to keep me on the track, and we used MBD to buy some raceman tyres for the wet.
And so to the engine!
So the chassis and front end are coming together OK, what about the engine...what have we got in mind there? Well lets take a peek at the spec:
Engine: TS1 225 with 190 degree exhaust & 128 degree transfer port timings. Exhaust port 46mm wide (chord length accross NOT around cylinder - equates to approx 51mm around cylinder!). Exhaust port externally matched to gaskets and pipe. Inlet port left standard (for now), and boost port widened to 26mm. Enlarged transfers to crank case and cylinder (max with no welding) all ports fully chamfered, matched and flowed. We could have gone a lot further on the tuning, and do infact intend to do so in future...however...after a few discusions, we decided to let me find my feet on the track first, and also opt for reliability, torque and traction in my first few races. We then have some rather funky modifications in mind, which we will be excited to reveal as and when they happen, but for now....i just need to get round the track and a) not crash or b) breakdown, so this spec will suffice for now.
Crank: 58/107 AF race crank, uprated RB bearings and con-rod, tig welded pin.
Piston: MB grade-B race-tour piston (newer version with improved windows)
Head: Taffspeed high-comp head
Carb: Open mouth 35mm Mikuni TMX fed into Yamaha reedblock with MBD 5mm packer. Jetting details to follow.
Exhaust: JL4 exhaust (until we get a hand-made one-off).
Flywheel: Lightened flywheel with Nylon fan
Clutch: Lightened clutch basket from a 5-plate clutch sytem....upgraded using a FOXHAT clutch spider, which converts the 5-plate to a 6-plate using a 1-piece billeted spider, with no packer, welds or rivets.
Gearbox: Li150 gearbox (11-14-17-20) with 16/47 sprockets.( obviously changable between cvicuits etc).
As mentioned, way back at the begining of the article, we have not done a 100% dream shopping list, we have worked to a budget and done the absolute best with the parts that we could beg and borrow, and the funds that we could find. There might be options in future to change the gearbox, carb, con-rod, piston, head...etc etc and lots of other bits....the list is endless, and could get more and more exotic by the minute....but the budget racer theme is to be followed, and we are doing the best we can to stay on that track(excuse the pun) for at least our first season!
So lets see some more pics....
Below: Bits laid out for Mr Brady to start work on
Below: Choice of Tassinari or Yamaha block. AF race crank that failed in a standard TS1, has been rebuilt by Jerome at Readspeed using uprated bearings and rod, plus pin has been welded. MBs latest race-tour piston, with improved cut outs for better port timings, and also MB packer plate for Yam-block and MB 'finger' manifold. The TS1 cylinder itself has now been ported, you can see from the pic below that the transfers have been taken out to the maximum proportion (without the need for welding up and re-carving).
Below: This is a pic of a standard TS1 exhaust port. 40mm wide (not the cylinder we used).
Below: This is a TS1 exhasut port widened to 46mm and raised to 190 degrees (approx 2-3mm depending on other factors such as deck height, casing tolerances etc etc - this is set up using a timing disc).
Below: Casings are ported out to give a better transfer flow for the gasses. Also internal casing materials are removed where they can be, to aid flow and to reduce primary compression.
Below: Starting to come together now, new seat is on, shocker is slotted on, gearbox is shimmed up correctly and slotted into place, and the build is starting to advance.
Below: Finally the scoot is starting to come together!! Frame and front end are together, anti-dive set up is securely fitted corectly, race bars are in place, hydraulics are plumbed in, tubeless rims fitted....etc etc...so looking good!
Below: Foxhat clutch spider in place, 6-plates and rest of engine internals. Kickstart removed and chaincase blanked off, still need to lockwire oil plugs.....but thats next!
Above & Below: Rearsets slotted on, shocker in place, lovely Mikuni 35mm fitted to Yamaha reedblock. LD petrol tank HEAVILY modified and fitted with fast flow tap. Looking good!
Below: Bars, again...HEAVILY modified. They don't look like much, but lots of work into these.
Below: Modified flange to assist with cooling, cowling will be getting some funky scoops too.
Below: Yup, that's me.....trying the sucker for size....perfect fit! ;o)
That's all for now, its a long, process.....but we will get there!
We missed the first race at Mallory, but Donnigton is just around the corner!
Updates to follow soon......
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