Late but sincere congratulations to our Dead Languages Person for
his witty essay on the Roman Civilization.It is surely one of
the joys of this group to see such broad ranging and -civilized- discourse,
for which our chairman and comptroller is also to be praised.Long may it
remain so.
Oiling problems have been mentioned when racing MGB's and many failures
attributed to lack of oil pressure.But is that so ? How much pressure is
really needed to avert collapse of main or conrod bearings ? I would like
to bring as an example of how little oil pressure is needed some
worthwhile historic cases.
First (obligatory LBC contents) the pre-war straight six or straight eight
Hudson engine.No doubt an American engine, but fitted to a number of Anglo-
American hybrids,including the Railton,along with its 3 speed 'box and its
quaint cork clutch.This engine,until 1937 relied on the splash system,in
which each conrod cap was perforated vertically through the center and had
there a little spoon that dipped into a trough filled with oil.The dynamic
impact effect of the moving conrod created some pressure that fed also the
bearing and an oil mist that lubricated the cylinder and camshaft.Many
engines used this system because of its simplicity and because it seemed
to work well.Pressure lubrication as an alternative had been
available much earlier,at least from 1915 or so.
In 1937 Hudson replaced this ancient system by pressure-lubrication, via a
small plunger pump that gave 3 psi maximum.Now the Railton used the 1934
splash lubed Hudson engine and it performed quite well.Railtons had
according to "Autocar" tests the best acceleration times recorded in
England pre-war.In Australia the straight eight Hudson engine was used
in a very fast Hudson Special that with the help of 4 carburetors and tuned
exhaust had much success in the early and middle 50's.And it must be
recalled that in America,the first NASCAR champions were the big Hudsons
which defeated overhead valve V-8's consistently with a modern version of
this same sidevalve six.
The other example (tenuous LBC connection ) is of course the Chevrolet
inline six cylinder ohv engine,made from 1932 to a few years ago,as truck
and passenger car engine, in countless versions and derivatives all over
the world. During its first, and very successful, version ( in which
Chevrolet displaced Ford as the best selling American car )it had splash
lubrication,changed to low pressure pump in the late 30's. But the old
engine was much raced in its unpressurised form. In Argentina, the famous
Juan Manuel Fangio raced Chevrolet Specials for some 15 years,not only
Coupes in open roads but also open wheeled cars in circuits. And it was due
to his success in all types of races with the Chevy engine that the
Argentinian Government sent him to the F1 races in Europe in 1951.The rest
is history, as Fangio won 3 times the F1 championship and became the most
respected of the great F1 drivers,one who is the yardstick of excellence.
One amazing race that Fangio won was the pre-war Buenos Aires-Caracas race,
over terrible roads and reaching altitudes of more than 4000 m in Bolivia
and N. Peru.It has to be the ultimate proof of the stamina of a splash
lubricated engine.The competition included engines such as side valve
Ford V-8's and a few Dodge and Plymouth engines,all of them of course
pressure lubricated.Only American iron was good enough for these races.
Sergio Montes Department of Civil and Mechanical Engineering
University of Tasmania
Box 252C,Hobart 7000,Tasmania,Australia
Ph. 56-02-202113 (Int) 002-202113 (Australia)
Fax 56-02-234611
e-mail montes@cmech.utas.edu.au
"Lo bueno,si breve,dos veces bueno" Gracian
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