A bad day at the Office

It was bound to happen at some point in time. By all counts literally everything has always gone without any major hassle on almost every race day that I've competed in. Well, this one was different. Quite a bit of trick work was done on the Datti between the last race and this one done on 5 June. Nothing out of the ordinary was done either and merely included implementation of a multi spark distributor with rev limiting capabilities and a device to better control carburetor air flow efficiency. At least that was the planned and desired outcome of the modifications done. Fridays weather was overcast with cool air in circulation. We arrived at the track just before noon in order to do final prep for the afternoon practice sessions. The 140Z required a change in tyre from the 10" variety to a more subdued 8" variety. Some minor fastening was required but otherwise was ready to be tested. The Datti was as ready as ever with only tyre pressures and fuel requirements before taking to the track.

Our first session was out 13h40 but was somewhat delayed due to an earlier oil spill on track. We eventually took to the track eventually at 14h30. From almost word go, there appeared a hesitancy at around 7000RPM which has previously proved to have been dirt in the fuel system. After 3 laps it was apparent it was not going to clear and I duly proceeded to the pit complex. Again a strip down of the carbs was done and lo and behold dirt was again encountered in the float bowls but this time none in the needle and seat or banjos. The carbs were drained, cleaned and put together again. The air jets were changed for a slightly richer setting.

The 140Z on the other hand showed it was still well in contention albeit with a smaller foot print. No further testing would be required and the 140Z was put to rest for the day. I again took to the track at 16h00 for our last session only to find the same (misfire) problem still present. Again I returned to pit. This time the plugs were changed, just in case. The timing was again duly checked and the distributor was checked for any excessive wear/play on the rotor. The implemented air flow device was now removed as well. Everything else appeared normal and within acceptable allowances. All checks done seemed fine and she cleanly revved to 7000RPM. We would now have to wait for the morning during qualifying. A traditional 'braai' was had along with a few well deserved beverages.

Saturday morning and we got to the track at sparrows (06h15) and again prepped the cars for qualifying. By sunrise it was blatantly clear that early morning mist was present and resulted that qualifying was eventually abandoned for safety reasons. That left us in no better position for the race. Our first race was at 10h40 and the grid was now determined from our finishing results from our last race on May 8. As such I found I was now the meat in the Scirroco sandwich in class B with Sandro Biccari ahead and Johan Swart behind of me. I was now on new batting turf. A normal rolling start was done in which I got away cleanly and ahead of the class B cars but coming out of turn 2 the misfire was now again there at around 7000Rpm and getting worse by all accounts. It seemed to last longer and was more noticeable. I returned to the pits after the very first lap somewhat dejected by it all. The 140Z on the other hand was not in the same league as the Porsche of Keith Rose this time around due to being on the 8" tyres but none the less still put up another class X time of 1:22.8 thus ensuring his further participation therein. I in the meantime started stripping the carbs again in hope of finding more dirt. The 'Guru' eventually returned to take over from my endeavor and it was clear that ideas as to the problem were now becoming perplexing. We drained the very last drop of fuel, cleaned the tank, checked the fuel filter, removed the fuel header tank, cleaned it thoroughly, and again cleaned carbs which turned out to be perfectly clean anyway. We put that all together again and decided to go back to basics by further removing the newly installed multi spark distributor. We put the standard coil back and now hoped for the best. All our new imposed modification now came to naught after all of that. We now hoped that race 2 would be back to normal in which we would now start from the back of the field in position 23 by my own choice.

Our last race was at 15h15 and all and any pressure was now off me due to our mishaps. Everything seemed OK until I again hit just above 7000RPM when the misfire was again present. Damn, damn, damn I screamed inside my helmet. I tried to now do a final process of elimination and noticed firstly that if I backed off slightly the miss cleared. If I further accelerated it would again appear once reaching just over 7000RPM. Could it be carburation after all of this? I continued until I eventually noticed that as soon as the rev counter went over 7000RPM it suddenly shot to 10000, then back to 7000, again back to 11000. I suspected the shift control and turned this off with no change, then completely on also with no difference. All during this time I still managed to catch the class E and most of the class D guys but was unable to do so getting beyond 7000RPM. In a final and desperate attempt I tried to physically break the wiring going to the rev counter but was unable to reach the wiring sufficiently due to being strapped in and I eventually abandoned the attempt. The positive was that I finished the race and made up 11 places after all of that and still with a misfire. I can now only put it down to being a faulty rev counter which we will replace for the next race. A very frustrating weekend indeed.

The 140Z was having no such problems on the other hand and made a thoroughly enjoyable race with the other class X and class A guys, which from reports received, had the spectators most excited. The 140Z will now undergo engine maintenance for it's next encounter which will be in Port Elizabeth on the 14th August.

We'll show that Datti who's boss next time out Boet, you better believe it!!

Thanks 'Boet'