Neil - I like fettling just as much as driving and I must say that during lockdown and two salty winters it's been a much appreciated challenge and learning experience.
Having now done about 2000 miles with the Augusta I thought a few comments on the success or otherwise of my fettling activities might be in order.
I bought the car from Italy, mainly on the basis that it is in very nice, sound bodily condition and was from long term ownership by an enthusiast who had recently passed away. There was no opportunity to really assess its mechanical condition which turned out to have a number of issues, fortunately none too serious. Mechanical problems are more easy to solve than bodywork issues.
The most trying problem was vibration which has taken a lot of effort to cure. The culprit was, as I first thought, the propshaft. After being sidetracked by having it professionally (but badly) balanced, which seemed to make no difference I replaced the fabric discs and centerng spiders and eventually worked out a way of balancing the whole unit by supporting it on two level bars on which the centering spider bosses could roll. A Jubilee clip and a small piece of lead resolved the issue.
There were also vibrations from the engine, significantly reduced by replacing coil, points condenser and plug leads, grinding the valves and getting the mixture right. I had not understood that the two leaf springs which support the engine bearers also incorporate a vibration damper in the form of strips of brake lining between the leaves. One side was seized and the spring leaf surfaces covered with solid black gunge whereas on the other side the leaves were polished. Sorting that out greatly reduced engine vibrations to an acceptable level. The carburettor (Weber DO) suffered from a worn slow running jet and seat which I remachined, greatly improving the carburetion as confirmed by readings on the Air /Fuel ratio gauge I fitted. Subsequent experience shows that the carburettor is as it should be since the A/F ratio fluctuates around 13.5 to 1, dropping to about 11.5 to 1 when pulling hard uphill. One curious feature of the carburettor is that the choke can be used to enrichen the mixture when pulling with the throttle wide open - this works and the A/F ratio goes down to 10 to 1 with a small but detectable increase in power.
I had the cylinder head re-faced and ground the valves, fitting a modern oil filter and rebuilding the water pump with a new stainless steel impellor shaft but re-using the original rope gland. I improved the water flow to the rear corner of the head/manifold and made a simple copper “heat exchanger” to replace the exhaust flange gasket with the aim of drawing more heat out of that corner of the head. This does seem to help as there is only a slight degradation of the paint at this point after 1000 miles. I sealed the flange joint using “Heldite” sealant which has worked well in sealing this unit of three plates of 3mm copper but no gasket. The engine is now leak free, starts immediately from cold and runs with no flat spots or stalling when braking to a standstill. It had been rebuilt by the previous owner with a crank regrind, rebore and new pistons and cranking by hand tells me that the compression is excellent. It runs about 1000 miles on a litre of oil and does not smoke either on starting or after a steep descent. The modern oil filter leaves the oil clean on the dipstick for at least 1000 miles.
The gearbox needed a full rebuild with new bearings and attention to wear on the front end of the input shaft and at the front of the main shaft. The freewheel was very worn but, thinking that I would probably not use it I decided to remove it altogether rather than tackle the worn parts. With the gearbox out of the car I discovered that the large coil spring of the clutch was very much out of true and would not sit squarely in the recess. A new spring was fitted. None of these gearbox or clutch jobs made the slightest difference to the vibration, or even to the characteristic growl of second gear! The clutch did not need relining and with the new spring is smooth to engage and does not slip. It’s a delightful box to use - who needs synchromesh!
I abandoned he curious float and string operated fuel gauge sender and made a new unit utilising a helically twisted metal strip which is turned by an adapted modern E10 proof float and connects via a small pair of bevel gears and cable to the gauge. This works .
Two more major tasks were involved. The front suspension was filled with grease so had to be dismantled to clean and check. It turned out that some of the minute sprung loaded valves were coil bound on their closing springs so hardy surprising that it bounced and clattered. All is now in order although it does still drip oil from bottom of the sliding pillars.
The final major task was to rebuild the rear friction shock absorbers whose wooden discs were worn very thin. I replaced these with new discs laser cut from thin oak and reassembled the units which are preloaded with a coil pressure spring, changing this for an Andre Hartford style star spring and adjusting nut. The links connecting the arm to the axle were remade to a more machinist friendly design with polyurethane bushes. The shock absorbers appear to work satisfactorily but made an annoying creak at low speeds when greased with normal grease but this was cured by using molybdenum disulphide CV joint grease on the discs. I replaced the front eyebolts and all bushes on the rear springs and fitted new brake cylinders as these were scored and tended to seize.
Of course there were many more small jobs done but I finally have a very useable, nippy little car with superb road manners which makes other cars seem clumsy. I have really enjoyed fettling the car, the design of which is so different to other makes, sometimes eccentric, but mostly very effective and full of character. I am now making every excuse to use it and enjoying that too.
I don’t have much more to report having gone through almost every part of the car with the exception of the rear axle (which touch wood seems to be in good order and reasonably quiet. Hopefully these are last words but not famous last words!
I’d like to say many thanks to all those who have advised and helped me over the last couple of years and to thank you all for your interest in Augusta Progress.
Mike
