Aurelia B20 camshafts....fill me in....

[Parisien]

Can anyone tell me the differences and or indeed part numbers/identifiers of the above, from 1st to 6th series, how interchangeable are they, what to expect if if you could interchange them?


P

[Sebastien]

You could start with reading that:

http://aureliatips.lanciainfo.com/Aurelia_Tips/What_cam_to_use.html

And for a B12 engine, you should use the B12 camshaft!

[Parisien]

 

Thank you Sebastien....just some one else was camshaft pondering......


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[chriswgawne]

Just to add to Sebastiens post, we have twin Weber 40DCs fitted to a couple of our 2,5l Aurelias and whilst they look and sound great, there is no real benefit unless the engine is in a healthy condition, the camshaft is changed for a more aggressive one and the heads are gas flowed.
When all this is done properly and the carbs are in good condition then the engine revs much more freely above 4,800 rpm and there is significantly more power from about 3,500 rpm. My race engines have camshaft fitted which are modified to the extent that the pushrod lengths and the valve rocker gear have needed careful modifying to avoid fouling but it has been sell worth the effort.
For a road going twin carb 2,5 litre Aurelia, I think 2 X Weber 36DCs are a much better proposition but they are even rarer today than the 40s.

On a slightly  different note I have said for years that the early 2 litre B20 engines with the 2 X single choke Webers are much more free revving than the later standard 2,5 litre engines and its nice to see it confirmed in print in the attached article.
Similar can be said of the early B20s generally in my opinion as I usually find they are lighter, more tactile, pleasant  and sensitive  than the later ones if they are well sorted. They just run out of steam a little on motorways.

Chris

[Parisien]

Thanks again Chris for the insight and your experience of up-graded camshafts and using them in racing form.

Just wondering, are any of the camshafts truly interchangeable....?

P

[Parisien]

You could start with reading that:

http://aureliatips.lanciainfo.com/Aurelia_Tips/What_cam_to_use.html

And for a B12 engine, you should use the B12 camshaft!

Having now read through the link Sebastien, it more or less answers most queries, thanks


P

[Parisien]

So this is why the B24 Spiders have become so expensive......

"Addendum B
4.17.11


The B24 Spider camshaft is listed in the parts book but rarely seen. Three B24 Spiders have been found with B12 camshafts installed, and with the specs of the B24 Spider camshaft and the B12 are so very similar, there is the possibility that they simply used the B12 instead"


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[Parisien]

This company was mentioned in the Aureliatips blog above as a manufacturer of camshafts, valves, pistons cylinder liners and flywheels (noted a race Aurelia 4kg flywheel)


Indeed are they the main maker of all parts for the Aurelia engines?

http://www.sergioallais.com/storia.html


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[GG]

Sergio Allais is indeed a very interesting small manufacturer. Seeing the rows and rows of camshaft lobe profiles that they had on hand, with their ability to make anything you wanted to your order, was certainly impressive. They also made crankshafts from scratch, flywheels, etc. That said, I thin they are one of several suppliers to Cavalitto, who uses different ones for reasons he knows better than we do. At one time we found that he had replacement camshafts from three or four different makers. Allais is the only one I visited, tho, and their father had a pretty good reputation some many years ago for machining.

All the early camshafts (up through the s.4) are interchangeable. The easiest answer is to talk to Cavalitto and get what he recommends. He has (typically) a standard B10, the warmer s.3/4 or B22 cam, and usually a hotter one, which is like a detuned Nardi cam for the street. The pure Nardi cam is rarer than one might think, and has its own oddities, and is not recommended for normal use. Cavalitto can also get what you want made up, if he doesn't have it. The B24 Spider America camshaft is a real rare bird, but not really all that desirable - its an odd, being detuned with a bit less power and more torque, as Lancia felt the Americans wanted something a bit easier to drive.

If you are rebuilding an early (s.1-4) engine, change the lifters to the ones with the holes on the sides. The original design (holes on bottom) is one of those rare "oops" by the factory. Then you have to shorten the pushrods about 1/8", as the newer lifters have a slightly different internal ride height for the pushrod. You can heat up the pushrods, pull off the end, cut , and replace the end. They can be reused, if done right.

Like Chris mentioned, the easy revving of the 2 liter is just delightful. Mine has a few lbs off the flywheel, and some lovely header pipes (Italian made, late 1950s), so it might rev a bit freer than the norm, but the lower reciprocating weight of the smaller pistons is quite noticeable. Its comparable to the difference of a Giulietta and a Guilia (1300 vs. 1600), which if you run the numbers, comes out to the same 2L vs. 2.5L. My s.2 B20 pulls on the motorway up to a happy 80 mph easily, but a recent rally in Colorado with Rich Darling's s. 3 B20 had  me watching him run away up the long mountain uphills! 

[Niels Jonassen]

I can only support Geoff's view that as a rule it is best to stick to the standard specifications. I have now used our Aurelia for many long drives to Italy, Britain, Sweden, Norway and Finland since 1982, and I have never had any reason to regret that I decided not to change the specifications when I restored it. I did, however, have the camshaft rebuilt to standard 3rd series specification. Distributor and carburettor have also been rebuilt, plus, of course, the engine. It is true that you can hear the engine working when om motorways, but it does not sound overworked, and it keeps pace with all other traffic. Oil pressure and water temperature stay where you want it. Usually I prefer ordinary country roads because that is where you can enjoy the Aurelia to the full. Just approach a turning, go into third and accellerate through. What a joy.