08/08/2003

This Quench Thing

Ricardo's "Shock Absorber Head" which was the successor to the "turbulent"
head was filed at the US Patent Office on Sept 17, 1928.  Patent # 2,076,593.
Patent issued April 13, 1937.

Ricardo's "turbulent head" the hemi-sperical chambered "classis" L-head was
filed on 31 December 1919.  Patent # 1,474,003  Patent issued November 13,
1923.

Hemispherical Chambers were preferred in older texts because of significantly
lower heat losses due to minimum surface area for any given combustion chamber
size.  This was considered to over-ride the WELL KNOWN superior quench of the
side valve - which was superior to even the obsolete and about abandoned
Single and Dual Overhead Cam and pushrod OHV designs.  Remember the ricardo
headed designs on 50-60 octane swill were at least a full compression ratio
better on compression than the obsolete valve in head designs - routinely
pulled an extreme for the days of 6.5 to one vs the best of the overheads at
5.5 to one.

Furthermore, hemi's do not build up lead deposits which will lead to
pre-ignition like other designs.  No pre-ignition, combined with large valves
and a centrally located plug made the choice of hemi-headed design's
desirable.

For automotive use, Alcoa aluminum had licensed both the turbulent head and
the shock absorber head and was providing fully cast heads or full licensed
use of ricardo's chamber and design and construction information for minimum
cost to the manufacturer that used aluminum heads.  By the end of the 30's and
the start of the "great unpleasantry" over 1/2 the car engines built were
using aluminum ricardo heads.

And BTW, Marmon was using an aluminum crankshaft assemblie with an Iron block
in the early twenties - so the use of aluminum was well established.