Thursday, 29 January 2009

Private Owner Downunder Part 4

A promising start to our return to the track after some major internal work. But would it continue to run sweetly in the lead up to the Nationals?

Li’l Speedy fired up readily in the driveway on Saturday morning 5 October, after some two and a half years being laid up in the shed. This was just in time to be packed on the trailer to tackle the 3 hour drive to get to the track for Saturday afternoon practice for the Collie 2+4 meeting, followed by racing on Sunday.

The last stages of the mechanical refit still held some frustration, with a decision to run the Hoffman bearing on the drive side with an imperial SKF on the timing side, rather than a pair of imperial SKF’s. This would solve the stretched case issue on the timing side and avoid boring a perfectly good drive side case. In addition the use of the Hoffman on the drive side avoided the need to make up a spacer for the mainshaft to allow the primary drive to pull up against it at the correct offset. This decision was also aided by the discovery of a tame hard chroming/precision grinding shop owner only 3 minutes from the office, who was able to grind the single lipped outer to provide the additional clearance needed for ‘C3’ specifications. So I now have a Hoffman / SKF main bearing set installed with another set on the shelf ready for the next time – many years hence one hopes.

We also decided to bore out the Hoffman bearings to take a decent thickness sleeve, as the difference between the 22mm shaft OD and the 7/8” bore of the stock bearing only allows a sleeve thickness of around 0.003” – too thin for a press fit without the sleeve bunching up. So I removed the rollers and the thin steel cage from both bearings to allow the ID of each bearing to be machined to take a 0.010” thick sleeve. The problem then became how to reassemble the damn things without distorting the flimsy cage – give me a solid brass cage like the original bearings any day. I also found an aero industry plating specialist happy to do motorcycle work so delivered the cam spindle and the bare oil pump body and top plate. He built up the outside only of the oil pump parts to restore it to shrink fit condition and similarly plated the embedded end of the cam spindle, which had become loose in the wall of the timing side case. While he was at it I had the taper of an old M17/2 cam plated to restore it to press fit condition and was then able to press it into a spare camwheel. I will try it in Kamahl the Clubman before too long – they are reputed to be a good sporty cam with better mid range than the M17/8.

After a wet drive to Collie, I was pleased to find the track drying by the time we were allowed out for practice. The vintage sports cars had not enjoyed the best of weather during their time on the track earlier in the day, however the late afternoon motorcycle practice sessions went well until a sidecar deposited a trail of oil half way around the track. So we finished the afternoon dusting the oily line and making it safe for the Sunday races.

Sunday dawned sunny so the pit area was abuzz as we prepared the bikes for the 9am warm up followed by the first of 3 races for Li’l Speedy in the Clubman class, which encompasses Sportslights (100cc 2 strokes and 150cc 4 strokes), Period 2 machines and rigid framed bikes built later than the 1946 cut-off for Period 2.

In race 1 we tagged along in close quarters with a small group comprising a Honda 150 and a B33 350 BSA, with another big bore 600 BSA within sight. Due to the fresh engine (self imposed 5000-ish rpm limit) and lack of familiarity with the track, I was happy to feel my way, eventually getting close enough to the B33 to finish only 0.05 seconds behind. Fastest lap 1:07.4 with 5:49 race time. A check over in the pits revealed only a minor oil weep from the rocker feed union which was easily fixed so after a fuel top up we were ready for race 2.

This time I focussed more on the lines that gave the smoothest ride through some of the corners, which were much bumpier than Wanneroo and gave the lightweight webs a workout as the pace quickened. Again I tagged along with the Honda and the 350 BSA, showing a wheel up the inside a couple of times. Li’l Speedy was strong out of the bottom turn and up the hill to the chicane, which is the place we grabbed 2 places when the BSA missed a gear as it went alongside the leading Honda, allowing Li’l Speedy to slip up the inside of both of them on the entry to the chicane, three abreast. It was a case of head down and try to make a break for the next lap, but still with an eye on the tacho – on 2 occasions I felt the end of the throttle wire and backed off a little. This produced the fastest lap of the weekend for Li’l Speedy and sealed a 3rd place in the race only 2 seconds behind the 600 BSA and a very fast DX100 Yamaha. Fastest lap 1:04.8 with 5:39 race time. Smiles all round back in the pits, as we all enjoyed the tussle.

For race 3 Li’l Speedy was finally on the front row so made the most of the position until getting caught in a traffic jam coming out of turn 3, which allowed the 350 BSA and the Honda past. In the run up the hill on the next lap we dispensed with the BSA and then got onto the back wheel of the Honda. It was racing at close quarters for the next 4 laps as we opened a gap on the BSA. On several occasions Li’l Speedy was able to pull alongside the Honda at the entry to the chicane but its light weight and disc brake gave it the advantage. Revs were allowed to run to 6-ish in this race but again I can’t recall feeling the end of the throttle wire as I was mindful of the work that had gone into this engine and didn’t want to spoil our chances of a shot at the Nationals. We finished with a strong run to the line, only 0.06 seconds behind the Honda at the chequered flag. Fastest lap 1:05.9 with 5:37 race time, so I was very happy to see continual improvement during the course of the day. And with a fully run in engine and flat out performance available I am sure that we will be up there with the 600 BSA and other bigger machines in future.
I guess you won’t be surprised to hear that the cosmetics still haven’t reached the top of the To Do List so it will be a mechanically sound but tatty Li’l Speedy that fronts up to the start line at Wanneroo on 22nd November. Stand by for a full report next issue and wish us luck – we have to fly back from the Warrnambool rally a day early in order to get Li’l Speedy onto the grid on Saturday morning. JJ

1 comment:

Greg. said...

Great story JJ.
I really find it interesting reading about not only the good times on a bike but also the not so good times spent trying to get these old jiggers to be reliable.
Good luck with the racer.