From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Conclusions and recommendations regarding water circulation modifications on a Hart machine.
Identifier | ExFiles\Box 179\3\ img032 | |
Date | 4th March 1932 | |
-2- REVERSALS. With the water system standard a surge occurred on closing the throttle slowly at 660 R.P.M. and at approx 800 to 900 when closed quickly. With the modified system there was no surge when the throttle was shut smartly. SLOW RUNNING. A complete water circulation was maintained at 450 RPM., but was improved by fitting a ¼" restriction at the rear outlets. CONCLUSIONS AND RECOMMENDATIONS. Although the above extra pipes provide a quick method of reducing the pressures and would enable the Hart machine to become serviceable in a very short time we must realize that the arrangement is not ideal, as it introduces extra connections which are a possible source of failure. We would suggest that the investigation be still carried on with the view to reducing the pressures and still maintain the single main pipe. For instance the connection between the Y branch and cyl jackets at the front are restricted also the rear branch could be enlarged and the lead in of the rear pipes from cyl jackets improved and thus avoid the back pressure built up by two columns of water meeting as previously described. These suggested modifications would be very simple and not interfere with the present carburetter arrangement. As the units mentioned are detachable. Pending further investigation and to enable to Hart machine to be got into servie quickly we recommend the following as only a temporary modification:- (1) Large water pump and 13/16 horn pipe restrictions. (already fitted.) (2) Adaptors fitted in place of the core plug at the front end of the cyl block to take ¾" dia pipe. The pipes to lead direct to the header tank could be suitably clipped to the rocker cover studs. (3) The rear outlet pipes ¼" to lead direct to the header tank and have a ¼" restriction worker at the cyl block end of the pipe. | ||