Augusta progress

[daniel.bangham]

Hi Mike, Je suis desole, we are fully booked (working) all summer. Sounds a lovely event. Have a great time. My Belna is almost ready to go on tour this June, just waiting to fit a broken brake adjuster. One major breakthrough was discovering that there was a fuel filter built into the carburettor banjo connector.! It was clogged. I think it might be deposits from the fuel tank that are being dislodged by the ethonol in the fuel.

[Mikenoangelo]

12 months since my last progress report and nothing new to say - the Augusta just works and very well too. We've done 4500 miles since 2019.

Last weekend we went on the Beamish Trial, a non competitive tour around Co Durham,  Cumberland and North Yorkshire for vehicles built before 1955, starting and finishing at the Beamish Museum in  Chester le Street. Run as a road safety event, it goes through superb scenery in the Dales climbing  many hills which were sections in the MCC London Edinburgh Trial of 1927 such as Tan Hill, Buttertubs and Askrigg Bank, with a picnic lunch stop at Bainbridge There were about 150 entrants and judging by the number of spectators everywhere on the route, the run creates a huge amount of interest for the public which has to be good publicity for the cause of classic motoring. Run on Fathers Day, 18th of June this year, it's a brilliant event.

The whole route is nearly 150 miles which with a 70 - 80 mile run from home to the start and the same to return meant a 306 mile day, fortunately my son Tim is equally keen so shared the driving. The Augusta ran perfectly of course and I suspect surprised other drivers with its ability, particularly around corners and downhill!

I have a self imposed maximum of about 3400rpm so cruise at 50-55 mph at which it seems very happy and runs at about 75C. Up the longest and stiffest hill the maximum temperature on a pretty warm day was just over 90C. The gear ratios and torque are such that it pulls well down to 2200 rpm at which point the next gear down is still within my rev limit. I would like to have a 5th gear of 19-20 mph per 1000rpm which would probably allow a 60 mph crusing speed but on winding roads you rarely hold up the traffic.

The vibration problems which I battled with for the first 12months are now negligable, except for the windscreen frame which clatters at tickover at 650rpm. I need to change the seals as they are a bit hard so perhaps that wilĺ resolve that one, which I suspect is provoked by the V4 pulses of the engine.

Alltogether a very pleasing car.

[Mikenoangelo]

No new mechanical adventures to report on the Augusta but last week we reached 5000 miles on the road in my ownership. Still brilliant, reliable and fun - thanks Vincenzo.

Mike Clark

[DavidLaver]

Hard work paying off.  Well done!

[Raahauge]

Augusta cranks.
I was about to post this note at the beginning of September but Mike got in first reporting his 5000, enjoyable, trouble-free miles so I decided to delay this less positive tale.

Following my earlier crank breakage I had a full overhaul with new white metal, a rebore and new pistons. The pistons are heavier than the originals but lighter than others have used.
I decided to have it balanced by Vibration Free which involved a small weighted disc attached to the front of the crank and drillings in the flywheel.
The engine went together very well and I was pleased with the work.
In use it was extremely smooth and I was delighted, cruising very happily at 50 to 55 mph.
After 1500 miles a vibration developed which I initially thought was prop-shaft but I quickly realised it was engine and by the time I got home, 40 odd miles, it was quite severe.
Upon inspection the crank is 0.002” bent at the centre main therefore 0.004” run-out.
It is not cracked.
I have chewed over the possible cause and discussed it with others and with Vibration Free but have arrived at no decisive views.
A hazy theory going round in my head is that the energy in the out of balance forces in the standard Augusta engine are dissipated by shaking the engine about and these vibrations are dealt with by clever engine mounts so that they are not felt by the passengers.
In balancing the engine in the manner that I have, all the out of balance forces have been resolved inside the engine between the two ends of the crank which may have imposed loads that it was never designed or tested for.
I am still trying to settle in my head whether there is actually any difference between the two scenarios.
Another possibility is that I have a crank with a flaw in it and that the balancing has played no part.
Either way my plan is get a new crank made to a design based on the later Lancia V4’s such as the Fulvia.
I have been given ‘an order of magnitude” price of £3000 with a 10% reduction for every extra crank up to a maximum of 6 (2 would be £2700 ea. 3 would be £2400 ea. etc.)
The design of this would take into account the weights of the pistons and both ends of the rods and for this pricing structure all the cranks would have to be identical. It follows therefore that if anyone else wished to join the project, all would have to agree on a common piston and rod weights to achieve an ideal outcome.
My rebore was 72mm and used an Opel piston, I see that there is a 72mm Fulvia piston but I have not yet established if that can be a workable option.
Any thoughts or comments most welcome.
I will be trying to put a budget cooking engine together in the meantime, I really miss not having an Augusta to use.
Hope to see many of you at the lunch.
Best wishes.
Mike

[Kari]

Quite a story your are telling here. My first thought was, as you write about increasing vibrations, that something must have shifted/moved. Can you run the engine without gearbox and clutch assembly, or is it disassembled already? What about the fan, the dynamo pulley? They can be out of balance too.

It seems strange to me that the crank can get bent while in operation? Would there be a crack developing?

Your "hazy theory" might not be far off. IMHO, the method of balancing an engine like Vibration Free is like fighting symptoms. Its not known what is causing the imbalance inside the engine. A con rod big end might be heavier than the opposite one and will cause excessive vibrations and centrifugal forces. Also, it's important to have all the masses of the big ends and the small ends within 1 gram. That includes the piston assemblies.
Before the engine was assembled in the factory, it was balanced using bob weights for the big end mass only. There is no information that the reciprocating mass was considered. That started later on with the Aprilia.

Last year I had the crank of my spare engine balanced. I made all the con rods and piston assemblies equal first. I then made bob weights for the crankshaft the same mass as the big ends. The crank with the installed bob weights was run on a modern Schenck balancing machine. It should be dynamic balancing. It turned out that weight had to be removed on the sides of the cranks (90° to the cranks) and a little at the cranks themselves. When the crank was within the limits, the flywheel was attached and balanced together with the crank. Finally, the clutch assembly was installed and it did need balancing too. I was rewarded with a smooth running engine.

I remember that the late John Millham had a balanced crank made, but I don't know if it was ever run in an engine.

Those of you who want to go into depth of the subject, I recommend the very interesting booklet by Geoffrey Goldberg: "Balancing the Lancia V4"

I plan to be at the lunch.
Karl

[ColinMarr]

The idea of a broken Augusta crankshaft reminds me of Andrew Maclagan's clever poem, based on Wordsworth's "Composed upon Westminster Bridge" – see photo. As printed in the LMC Journal of Spring 1967.

[Raahauge]

Kari, thank you for your considered response.
To answer you in order.
The engine was dismantled immediately and the crank measured, hence I know the run-out.
I also find it strange that it should bend in use, I have checked very carefully with a Magnaflux and it seems not to be cracked. As you remark, there could indeed be a crack developing
It is not twisted (as measured by the flat sides of the crank) and the bend is such that with the crank on V blocks the centre main is low with 1 & 4 at BDC and 2 & 3 at TDC (conventional cylinder numbering)
Before removal, the crank was free at TDC but a little tight when the pistons would have been halfway down the bores. The white metal looks OK but it must it must be slightly damaged as otherwise it would be equally tight everywhere.
The oil pressure remained good but the oil pressure relief valve may have been spilling less.  
I did very carefully balance all the components before taking it to VF but only to about 1.5 to 2 grams. and the clutch parts were marked and reinstalled in the same position after the balancing.
When balancing last year did you consider dealing with a proportion of the reciprocating weight?
John fitted his balanced crank which was satisfactory though he was rather distracted and very concerned by the very low oil pressure. He took it back to the company who did the engine work before he was ill and they are dealing with it. When John had the new crank and the engine work done he changed from white metal to shells and it seems that the thrust pieces in the centre main allowed oil to escape.
I concur, the Goldberg book is excellent on the subject.
I look forward to meeting you.

  

[Spider2]

Regarding the bent crank: There are companies out there who will straighten a bent crank with a high degree of success for about £150. Surely this is worth a try. I do not know the metal properties of an Augusta crank as to whether it is suitable for straightening. More modern cranks certainly are. One company I read about recently was South Cerney Engineering. Maybe worth a chat with?

[Kari]

Mike,
Another thought: When you had the main bearings line bored, was the crankcase firmly bolted to the block? As other Augusta owners and myself have experienced when the mains are bored in the crankcase alone, it wont work. The crankcase isn't just rigid enough. In my case, when I had to remove the block from the crankcase with the crank shaft in situ, it would not turn anymore.

When I had my crankshaft balanced, I used bob weights for the big end mass alone, although in Geoff's booklet there is a calculation published which gives a value of 32,2% to be added for the reciprocating masses. (Page 90)

Regards  Karl

[Raahauge]

Thank you Kari and Spider.
Thank you for the suggestion,I had thought of, but dismissed, the idea of straightening the crank.  Unless I change something it would surely happen again and if I put it back to standard I would still be running with a possibly weakened crank and the attendant worry about its reliability. 
I had assumed that the engine would be line-bored with the block in place but in the event it wasn't as they said they couldn't get it on the machine. In practice that didn't cause a problem as everything turned beautifully on assembly. It really was a delight in use and the problem arose in quite a short mileage. I don't think I 'over-reved' it but maybe 55mph, although well under Lancia's suggested max, was too much for the loads I may have imposed on the crank - back to my hazy theory.