Introduction

People want to know: what cam to use in their now “improved” and restored Aurelia? How can they get more performance? What improvements are available? Some thoughts follow:

1.    use the standard factory cam

The cars are remarkably well tuned and engineered to run with the factory cam. Setting them back to the way they were designed is the correct thing to do. It is important to get all the parts and pieces working correctly - especially so in an Aurelia. So that is the first recommendation.

Which cam? Lancia made 5 different cams for the Aurelia: (1) for the stock B10 and the rest of the two liter cars, (2) a cam for the B22, (3) the B20 3/4th series, (4) the B20 5/6h series, and lastly, (5) a reduced performance cam used only for the B24 Spider America. Most all had 5 mm lift, except for the B22  (5.5 mm). (Please see Addendum B below)

Most (the B10, B20 5/6th series and B24 Spider America) use the same lobe geometry. Only the B20 3/4th series and B22 are different.

The B20 5/6th series is a dimensionally different cam, with an increased lobe but of the same geometry - with a larger base circle to reduce wear. The earlier cams differ a wee bit in their base circle but the real difference is in the later 2.5 motors, which had revised lifters to go with the s. 5/6 cam. 

2.     work better with stock components (blueprinting)

Make the engine fresh and good. Many engines are not - they have low compression and while smooth, are not up to factory standards. Getting performance out of a tired engine, even if it seems good, is not an effective path. For example, some parts of the valve train wear significantly and effect performance. Getting all this truly back to factory standards is the first course of business.

Secondly, the carburetors and ignition should be carefully set up to factory or as new standards. Many carburetors of that period by now suffer from wear, especially  around the spindle shaft. This causes them to leak air, thus making it difficult to have accurate tuning and setup. So too, carb jets may not be accurate to their standards, having been modified over time.

Some of the cars suffer from excessive wear on the cam - the early (up through s. 4) lifters were not of a good design and they promoted excessive wear of the cam lobe. So inspection of the lobe is important, as is changing the lifters to the later type.

Ignition is an area where technology can help. Electronic ignition is recommended. Once, a good running Aurelia engine, that ran very well,  was put on a chassis dyno, and after about 5000 rpm, performance started to die off quickly. This shoed a previously unknown problem with ignition, as the points just weren’t working well. Whether it was this car, or perhaps points in general  - electronic ignition seems to enhance performance at both the low and upper ranges, promotes cleaner burning and more accurate sparking.

These changes to the car can now be almost invisible and is easily reversible. A single small wire out of the distributor to a setup under the dash is all that you see. More power, better running, easier starting, enhanced durability…. Hard to resist.

3.carb sizing, Nardi, and cams

There are many variables in play here, all interrelated.  In many cases, the standard cam used is fine, but the air flow is limited through the stock carburetors. This (I believe) is more common in the early cars – Martin Cliffe told me that he put an early Nardi setup on an engine with the stock B10 cam, and that the performance was enhanced significantly, even with the standard cam. He thought there was plenty of life in that stock cam, and changing the cam wasn’t required.

Tim Burrett has used a different approach for performance on his 3rd series motor - by making a  larger carburetor. His has larger venturis machined into a stock body. He gets good airflow with the simplicity of a single carb. He puts his big carb for the races, and a smaller one for driving home.

People’s perceptions of the performance enhancement with the Nardi 2 carb (on the 2500) setup vary. As it is an awkward installation (you have to pull one head to get to all the manifold fasteners) it is rarely done on a stock car without other work at the same time. The Nardi setup certainly sounds great and makes good noise (intake air). Some don’t care for it, saying that it doesn’t do much if everything else is left the way it was. More carburetor only helps if more air is flowing – and up to about 4000, it probably doesn’t do a lot except dump in more fuel through a second set of accelerator pumps!  There is something to be said for the simplicity of the stock setup.

On the other hand, if the cam is a bit improved, and the Nardi setup is well done, aligned carefully and jetted right, it can be very satisfying on the 2500 cc motor.

For the two liter motor - the situation is a bit different. The Nardi carb setup is for two Solex twin barrel carburetors. The stock setup - with two single barrel Webers and standard cam (and flywheel) revs very freely, and is quite satisfactory. Even with the stock flywheel, these motors rev very well, due to the smaller pistons and conrods, with less reciprocating weight. There is little need (to this author) to change the setup on those motors. Given their slender conrods, the stock setup is recommended.

4.What cam to choose?

For the 2500 cc motors - the best of the stock factory cams is the 3/4th series B20 cam, or even the B22 cam. These have a good profile and pretty good lift. Of course, this cam can’t be used in the 5th/6th series cars, as those have a bigger base circle. For the later cars,  cams have been made with these earlier profiles.

In the world of aftermarket cams, note that the original Nardi cam is quite radical. Its exhaust timing is extreme, and while it revs very freely, it is not a good cam for the street. Truth to be told - they are very rare in the US - most are aftermarket “Nardi” cams , modified from the original cam.

Cavalitto has had moderate performance cams made that are in between a stock cam and the original Nardi. These vary - some hotter than others. Enrico at Cavalitto knows these pretty well. Walt Spak has put one in an engine with success.

In the US, aftermarket cams have come from Megacycle in California who have made cams for Aurelias since the 1980’s. They have experience and make a good cam for the street - their # 90199 profile is an excellent cam. It works well with a single carb. Both Ed Godshalk and Tony Nicosia have used this cam successfully. I had a B20 with this cam and was also quite happy with it. It boosts the peak performance point up about 3-500 rpm from the stock cam, but is quite streetable.

Dema at Elgin Cams in California has made a cam for the Aurelia for me - they are easy to deal with and very competent. Also, their cam profile is probably a bit more up to date. Their cam in a B24 engine performs very well, although more suited to a twin carb setup. It is a bit lumpy at idle, like a Flaminia 3C, and revs freely up to 6,000 rpm without difficulties.  It is good fun in 3rd gear, and yet still has some good bottom end, although not as much as a stock cam or the Megacycle.

5.What engine to have?

Which cam to use depends on what engine you want to have and how you want to use it. Each car has different needs, and the engine should be designed to address those.

I had a B20 4th series for many years with a two carb Nardi setup, with the Megacycle 90199 cam. In general, I was very happy with this car, it would pull to 5300 in 3rd gear up long Colorado hills forever. It may have pulled higher, but I didn’t try. It also passed my “Chicago” test – able to pull from a stop in 2nd gear. Its performance was balanced nicely between revving and pulling down low – I’d guess it was breathing better than the stock cam, but still oriented to lower end power.

I have also built a slightly hotter engine, with the following:

-Pistons – 9:1 compression

-Carbs – Nardi setup, redone

-Ignition – electronic

-Cam – new one reground by Dema in California.

-Exhaust – stock

-Flywheel – lightened to 15 1/2 lbs

The parameters for the cam were that it have low end power as well as some enhanced top end breathing. A very hot Aurelia had been seen elsewhere with 10.5:1 compression, deemed to be  too much. Elgin Cams made the cam. Dema, the owner, has spent many hours on cam design and engine theory, and focused on increasing lift (6 mm) and a better “ramp up” design to get power. The cam is one for the street.  They reground my cam and sent it back in a few weeks. They developed a profile around the standard lobe cl (112º), so it wasn’t radical. Once installed in the motor, Barry Sales (PHP  north of Chicago) fiddled with the cam timing on the dyno to get the best low-end torque possible. At the end, we got about 140 ft.lbs. of torque, and 140 hp at 6000 RPM, and the engine was still pulling with no sign of quitting.

When the engine was first installed, several things were noticed:

•the engine pulled very well from 4000 on up, and would bury the tach (over 6000) in 3rd without a problem. It kept making power high up.

•it smoothed out down low once the jetting was changed (after about 5,000 miles in the car). The main jets have dropped to 130 from 140 used in the dyno run as the rings have seated. Starting from a stop in second is possible.

•it’s a lot of fun to drive. Cruising at 2500 is fine, but above 3700 the power really arrives. That’s a bit over 75 mph.

•the lighter flywheel and cam makes gear shifts much smoother. The gears just “snick” into place, and that older 6th series “lag” is gone.

The goal was to get some performance back – along the lines what I imagined De Virgilio et al would have done for the cars c. 1955. While not up to Lancia’s more radical work at the time  with SOHC engines, the result is very close to a Flaminia 3C 2.5 engine, a worthy goal. While its breathing may be a source of some of the improvements, careful assembly, better pistons and 9:1 CR, electronic ignition and a superior cam profile are probably what gets this engine to that level.

We have all seen the engine upgrades which are too radical and no longer maintain the Lancia character we all love. This is not one of those. This is a modest upgrade, one where that feeling of the Aurelia engine running out of breath at 5000 RPM is gone – this cam pulls and pulls, without ever loosing a step.

The Megacycle cam is a good one - it keeps the Lancia character and opens up the breathing a reasonable amount. Those who have had that cam in their engines tell of pulling past 5000 RPM without any problems. Perhaps with electronic ignition it would perform better.

The Elgin cam (and the rest of the work done on this engine) takes the car up one more step – more in the sporting side of GT, but not a hot car. It is still in keeping with the Lancia character, and perhaps even fulfills it more. There is a difference from the Megacycle and stock cam; while I really enjoy the stock cam and the Megacycle cams as well, this motor is something yet again.

The car loses only a wee bit of its “toodling” character, and yet picks up a whole other dimension. It’s a bit like an Alfa engine now, with a very linear and full power curve. It is a lot of fun to drive. It makes more power and torque than the standard engine over 3,000 RPM, and pulls well from second gear (once the carbs are dialed in). Its a lot of fun to wind it on out…. For more mundane driving, I wouldn’t go that way. For tight twisty roads, its not ideal - this is a hard call: its so much fun to rev this engine that you can lose your concentration on the road. On the other hand, the engine is so much more responsive that it is just the right tool to have at hand.

For general use, overall, a single carb and the factory standard cam are always recommended. One can pull a bit off the flywheel for a more responsive engine, but the stock setup is very good. Once you go down the road of enhanced performance, its is pretty seductive and hard to know where to stop.

12.16.06 (rev’d 8.09, 11.10)

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ADDENDUM A

Several machinists in Italy who make Aurelia cams - products from two or three have been seen to date. It is likely that in Italy, there is a great deal of cam experience gleaned over the years. Not readily communicated long distance, the improved cams (often marketed as “Nardi cams”) show thoughtfulness. All are more usable than the original Nardi cam.

Sergio Allais, near Turin, make new cams from billet, both stock or improved to whatever timing you want. Their “Nardi” type cams had more conventional timing (108 degree separation) than original; they seem to know what they are doing.

ADDENDUM B

4.17.11

The B24 Spider America cam is listed in the parts book, but rarely seen. Three B24 Spider motors have been found with B12 cams installed, and as the specs between the Spider America cam and B12 cam are so very similar, there is the possibility that Lancia simply used the B12 cam instead.

below: the machine shop of Sergio Allais, in Italy. They make cams for Lancias, Bugattis, Maserati, etc. Also pistons, cylinder liners, and flywheels. A race Aurelia flywheel of 4 kg is shown.