Augusta progress

[Mikenoangelo]

The extra port is an attractive idea or would be if I had a spare head (for the car of course ) but as there are many who run Augustas without major problems and the cooling  must have been alright in Italy when new I’m looking for a less radical solution.

I have a feeling that the long term owner and restorer of the car in Italy probably used it more for shows than energetic motoring as when I first ran it I had a lot of trouble with fuel starvation on long hills or at speeds over 50mph. This turned out to be due to a design incompatibility between the fuel filter which is Augusta, and the tap which is Ardea, a problem which took a long time to diagnose but once done, noticeably improved the performance as well as the starvation. I suspect it had been running too weak for years.

Augustas like mine with the Weber carburettor have the same economy weak mixture control as Geoffrey mentioned on the Aurelia. It is a quirky  feature which I’ve avoided using until, in future I fit an Air Fuel Ratio gauge so I know what is going on.

I found a very neat Bosch auxiliary water pump which looks ideal and is small enough to fit neatly under the dynamo, taking no more room on the left side of the engine than the Autoclean oil filter does on the right.

I've cleaned and dismantled the starter motor, a superbly made Bosch unit. Despite being fed 12v rather than the desiged 6V it seems in good shape, although the armature shaft has a bit of end float which can be resolved with a thin spacer washer. I'll also need to get the very slim spring which should be there to keep the pinion from tinkling against the starter ring as the original was missing.


Mike

[Kari]

Hello all,
I am sorry, I cannot share the opinion that the Augusta engine has a tendency to drop valves. There is no history on that. It is true that there are heat problems on some Augusta cylinder heads and the cause has been found almost certainly beeing faulty castings. The lack of essential water channels causes overheating around No. 4 cylinder and the exhaust port. In general, the Augusta engine is capable of many ten thousends of km running if everything is within factory specs. It can climb the Stelvio pass 2760 m / 9000 ft without fuss or do 900 km / 560 miles on motorways in 12 hours incl. stops for petrol and food. Lancia quality.
Pardon my English.

Regards Karl

[Mikenoangelo]

Karl - I'm happy to be guided by your experience on this - you car has been in the family for longer than many of us have been alive (not me though!). The only caveat would be if modern fuels do not suit the engine (I'm not worried about the ethanol content though as that was around throughout the 1930's to 1960 in the UK in Cleveland Discol at 15%) and if the car is driven too hard on motorways, remembering that it was probably rare in the past for a car to be able to go at full speed for more than a few miles - certainly in the UK. I'm just going to do what I can to cool that corner of the head.

Your English is perfect - a whole lot better than my Swiss . We lived in Bex les Bains in the Canton of Vaud for 9 months in 1963 and have very happy memories of that.

Cheerio
Mike

[lancialulu]

Karl - I'm happy to be guided by your experience on this - you car has been in the family for longer than many of us have been alive (not me though!). The only caveat would be if modern fuels do not suit the engine (I'm not worried about the ethanol content though as that was around throughout the 1930's to 1960 in the UK in Cleveland Discol at 15%) and if the car is driven too hard on motorways, remembering that it was probably rare in the past for a car to be able to go at full speed for more than a few miles - certainly in the UK. I'm just going to do what I can to cool that corner of the head.

Ethanol petrol does not burn hotter according to the new book https://www.amazon.co.uk/Classic-Engines-Modern-Fuel-Solutions/dp/1787115909

worth a read through....

[Mikenoangelo]

I dressed up the JB Weld repair on the pump impeller - more functional than pretty.(53)

Here is the starter drive pinion (54). There seems to be nothing to stop the pinion from floating forward to tinkle against the flywheel which it sometimes does. I thought a light spring was missing but now I don’t see how that would work as it would be squashed against the main spring when engaged. Can anyone advise?

The dynamo (55) is an original 6v Bosch marked RG 90/6 but running on 12volts with a replacement regulator (56) marked 12/130. I assume this permits the dynamo to operate on 12v which it seems to do happily. Can any electrical expert out there confirm that this is the case?

Mike

[Kari]

Mike,
I see you have one of the rare steel dogs.

On your starter motor the return spring is missing. I hope you have a spring maker on hand nearby. At rest, the dog is pulled back to the flange. On starting, the inertia enables the dog winding towards the ring gear and stops at the the heavy spring.

The dynamo does what the regulator tells it whatever voltage. However the voltage and current should be checked when back in use. Nominal output is 90 Watts. I think it will stand 130 Watts.

Regards  Karl

[Mikenoangelo]

Karl - my pinion may be the wrong one as I can find no hole to insert the wire tag of the spring. I suspect it will be too hard to drill but I can try - if you can tell me where! I assume it was drilled from the outside of the cylindrical part of the pinion.

There is a hole in the shaft which was invisible at first but visible now that I have fitted a spacer to reduce the end float of the shaft.

Mike

[JohnMillham]

I have a spare one left from a batch I had made a few years ago, so will send it to you. Is your address as in the latest (2013) VSCC list of members, ending in 5SY? Regards, John 

[JohnMillham]

I won't send the pinion,  just the spring. It won't go 'till Friday, 'cos I'm not allowed out. My "shopper" help will post it.

[Mikenoangelo]

Brilliant John - thanks. We moved so I'll email our new address. We also have the same post problem - yesterday a friendly council chap who was sweeping the carpark played posty for me.

I can see the missing hole on your picture so will now experiment to see whether carbide drills, rotary burrs or diamond tipped tools will do the job. The pinion is hard!

Mike

[Mikenoangelo]

Success! I found I could drill the starter pinion for the antitinkle spring using a carbide drill bit. (60)Tricky but 3000rpm in the milling machine with light pressure on the drill and cutting oil did the trick. I bought two 1.5mm bits, one of which became blunt immediately but the other, of a different brand, went through the 6mm thick rim of the pinion with no problem.

The starter and dynamo are ready to fit, these and a lot of other engine parts having been cleaned, phosphated, primed and top coated with POR15 Engine Enamel, a heat resistant paint which brushes on without brush marks.

I’m fairly convinced that adding an auxiliary water pump to feed to the hot corner of the head is possible without major irreversable modifications and worthwhile. I decided that if I put more water in I also need to help it out as the aluminium elbows to the radiator hoses are only 19mm bore, although the ports into the pump and out of the head are larger. I fabricated a new outlet elbow with 23mm bore and this now awaits a visit to the welder when we are unlocked (61).

Mike

[Mikenoangelo]

I decided to make a new spindle for the water pump as the original, although the gland did not leak, was quite worn at that point. I was unable to find any stainless steel bar which was of exactly 10mm diameter as per the original so had to machine one, lapping the last couple of thou to size, making the taper and machining the recess for the half round Woodruff key. This involved making a cutter for the task which was easier than I expected using a piece of EN 19 alloy steel and cutting the teeth in the milling machine. The cutter was hardened by heating cherry red and quenching in 50/50 kerosene and engine oil. The challenge was that it is small since the key is a chord, 2.5mm deep, cut from a 7.5mm diameter x 2mm thick disc. The key, as you can imagine, is very easy to lose!

I had to machine out and re-make the spring loaded washer which compresses the packing of the gland as it was jammed in the housing and lastly to drill out the rivet holding the impeller to the old shaft to replace it with a taper pin.

I received the new gasket from Johnsons Gaskets, within two weeks as promised. Here it is laid over the original which it matched very closely, so closely that you can't see the original.

Mike

[Mikenoangelo]

I made an experimental heat exchanger to fit between the exhaust manifold outlet and the down pipe as I suggested in an earlier post (photo 65). I concluded the only way to find out if it works is to try it. The fins are 12mm larger all round than the manifold flanges, in  3mm copper.

Likewise on the auxiliary water pump to add more coolant I bought a Bosch pump and rigged it up to test the output, measuring the flow with a water meter I have for the garden hose. The pump passes 12 litre per minute through a 10mm bore connection. Probably more than is needed so I shall need to slow the pump or provide a bypass for the excess, measuring the temperature at the corner of the head with  a thermocouple attached by magnet, and read on a multimeter. I’m still unsure about this idea but enjoy the experimentation. If I did go ahead the only modification to the engine would be a fitting to connect to the top corner of the cylinder block and a connection to draw water from the radiator bottom tank. (Photo 66).However on close inspection I concluded that the water jacket on the cylinder block at that point is only about 4.5mm thick and that installing an inlet connection might be a bit risky so I have decided to wait and see whether the enlargement of the water passage from block to head, and the exhaust port heat exchanger do the trick.

Mike

[Mikenoangelo]

With the head back from resurfacing and a light re-cutting of the exhaust valve seats, I lapped all the valves, checking that they would retain a puddle of paraffin in the combustion chamber overnight and then turned to the numerous threads and studs which needed cleaning up. Luckily very few were stripped but I had a few calls to Tracy Tools when I did not have the right tap or die. A majority of the studs have a coarse thread into the casting with a finer thread for the nut and as they are high quality steel there is no point in using carbon steel (CSS) taps and dies but instead use HSS, high speed steel which are twice the price.

I next tackled the valve gear, finding that both camshaft lobes and rockers contact faces were scored. A chat with the ever helpful Morris Parry convinced me that I could make an improvement, short of having the cams reground, by carefully stoning the cams with the shaft held in the lathe so I could roll it while cleaning the cam profile with a fine lap stone. The rocker faces were a bit more difficult but following a plan suggested by Morris, I made a fitment to offer the rocker to  the side face of a bench grinder wheel to produce the proper curvature of the cam follower. The face of the rocker has a radius of 21.7mm and with the rocker fitted to a bush mounted on a lever pivoted at 21.7mm from the side of the wheel the lever can be rocked back and forth so the “shoe” of the rocker is ground to the proper curve. Like many of these things it took a day or so of messing to get the fitment right and then half an hour to grind the rockers. One point to watch is that the shoe of the rocker is precisely aligned perpendicular to the face of the grinding wheel so that when offered up to the camshaft the face of the shoe contacts evenly across the cam. I found I could check this with a straightedge across four rocker shoes and could correct as needed by adjusting the packing under the ends of the base of my fitment which straddles both tools rests on the grinder. While grinding the rocker face the amount of “cut” is adjusted by means of the tappet adjustment screw which presses against an angle bracket screwed to the moveable lever, pressure  being applied by hand, and limited by the screw.


Mike

[DavidLaver]

I'm enjoying this.  Heat sink looks good, fingers crossed...

In photo 69 the bolt to the far right very close to the grinder-to-rocker contact patch is the pivot-bolt.

What I can't quite visualise is how the cam was lapped and if the lathe "just" was "a posh vice" to hold the cam.  Did you need something to guide the stone like a "filing rest" or was it possible by hand?  My assumption is that you held the stone by hand, braced on perhaps the tool post, and swung the chuck back and forth by hand.

I also like the peek at the Salmson mudguard in the background.