Old Business: Brake Time
In my last post I mentioned that the Alfatross' original brake fluid reservoir was something of a mystery: so many fiddly parts . . . what do they all do? Who made it? Well-known 1900 guru Peter Marshall saw the post and was intrigued. He forwarded the image to Don Cross, a colleague and student of the kind of arcane technology found in exotic cars from the 50s. |
| The Alfatross' diabolical brake fluid reservoir. The brass rod and piston on the left are upside down in relation to the other parts in the photo. |
The system works
on the basis that when you pull [the brass rod] up against the pressure of the
spring, the suction of the cup will fill the barrel with fluid which will then
pump it around the brake system. When the brake system is fully bled and the
reservoir full of fluid the rod should be pulled to its fullest extent and
should stay there ( if it doesn't - then you have a leak somewhere ). It will
over a period of many miles gradually work its way down, but the idea is to
keep it fully extended at all times.
The system is then under some pressure and is
sufficient to take up any movement in the system, but not enough to actually
extend the brake shoes against their return springs. Gets rid of what I call
"stiction."
When bleeding the brakes, keep pulling up the
rod to pressurize the system and making sure you keep the reservoir topped up
otherwise you will push air into the system. This means it is a one man job
bleeding the brakes. Pressing the foot pedal will not bleed the system with
this type of arrangement. ( Nobody told me this when I had my first Appia and
it took a long time and much frustration until I worked it out).
Thanks Peter and Don! You have saved me a lot of time and effort. Hope I can return the favor one day!
New Business: The Engine
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| Side view of the 1900 SS 1975 cc engine: short and tall! Alfa Romeo 1900 Sprint, Gonzalo Alvarez Garcia. |
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| Front view of the 1900 Super double overhead cam engine showing the double chain arrangement. Alfa Romeo 1900 Sprint, Gonzalo Alvarez Garcia. |
Work on the Alfatross' engine continues apace. As mentioned previously, it is at Standard Machine in Phoenix with instructions to "blueprint" it. But what are we starting with? It seems that there were a number of factory engine options for Alfa 1900s. All the engines were 4 cylinders with cast iron blocks and double overhead cams, but there were important variations. The basic engine was an 1884 cc version producing between 80 and 100 horsepower, depending on which of the 5 different carburetion options were fitted. The top engine option was the 1900C Super Sprint with a displacement of 1975 cc producing up to 115 horsepower at 5,000 rpm. This engine, fitted with a pair of dual downdraft Solex 40 PII carbs and mated to a 5-speed transmission and a 9/41 rear end could take a relatively heavy steel bodied Alfa 1900C coupe to 190 km/h.
So which engine does the Alfatross have and how do we know? The first clue is the engine serial number: 1308-01541. This number falls within the 1900 Sprint Second Series production range for the year 1955. Other evidence is provided by external and internal features present in the Alfatross' engine, including the double chain arrangement used to drive the cams, the dual downdraft Solex 40 PII carburetors with oversized jets, double v-belts on the crank, water pump, and generator pulleys, 4 into 2 exhaust headers, 8:1 compression ratio, electric and mechanical fuel pumps, and cylinder head and cam characteristics.
What Was the Original Configuration Under the Hood?
The Alfatross' engine appears to be largely original with respect to the configuration of the engine matching the specifications published in the literature. When compared to other restored and "preserved" examples there are intriguing similarities and differences. Below are photos of the engine rooms of 7 1900C SS Zagatos in addition to the Alfatross'. Putting aside the various cosmetic differences and focusing on the similarities, all of them have the same basic 4-cylinder layout with tubular headers and black crackle painted cylinder heads and cam covers. Only one example has the distributor driven off the right cam. Five engines show either dual downdraft Solex carburetors or the large, flat, heavy steel air filter box appropriate for those carbs. The two other engines appear to have been retrofitted with side-draft Webers.The 7 examples below could be divided into three camps: engines that have been restored to enhance performance, engines and engine compartments that have been restored to present the best appearance, and cars that have not been--and may never be--restored in any way.
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| Car 01954 has a beautifully finished engine room but non-original carburetors. Note the unusual distributor location mounted on the right cam. |
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| Car 01941 also has a scrupulously clean engine compartment. Much of this car appears to have been "over-restored," but an effort has been made to retain the appearance of originality under the hood. Www.hi-think.it/luzzago. |
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| Car 01915 is obviously set up to run in events. The engine room sports some retrofitted performance enhancements, the most noticeable of which are upgraded carbs and wrapped headers. |
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| Car 01845 is a "preservation" candidate and should have one of the most authentic and original engines, but the normal shroud over the exhaust headers appears to be missing. Octane magazine. |
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| Car 01915 is another preservation class example with an amazingly original and intact engine room. Nothing seems to be missing or modified. |
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| Car 01931 appears to have a largely intact engine bay if the air filter box can be found. www.kidston.com. |
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| This image was on the Internet, but there was no information about its chassis number. Other than "cosmetic upgrades" the engine presents as original. Www.ultimatecarpage.com. |
