Tuning the 4 1/2-Litre Lagonda and Invicta
By L. S. Michael, O.B.E. (Continued from the January issue) In calculating compression-ratios use the method advocated in popular books on tuning, usually involving the pouring of liquid into the…
ITI-4:MS OF INTEREST
FROM VARIOUS SOURCES “Motor Sport’ s ” Technical Investigator writes
IHAVE just completed an extended trial of the Decarbo Exhalator, a device which, as was described in last month’s MoTOR SPORT, is intended to eliminate the formation of carbon deposit in an engine, while in daily use. The Exhalator comprises a bell-mouthed cylinder, into which is fitted a cartridge containing a chemical compound. The car on which the device was tried out had already seen four years strenuous service, and had not been decarbonised. for 9,000 miles. Before starting the test (which approximated 2,500 miles) the head was removed to ascertain the amount of deposit on the pistons, valves, etc. This was heavy and very hard, and the car was sluggish, lacked power and “
pinked” readily. My findings were as follows :—No improvement was noticed until about 200 miles had been accomplished, thereafter the engine ran•with less roughness, and knocking was less pronounced. With further use, the running improved still more. After 600 miles, the engine was examined and there was a noticeable decrease in the carbon, while that which remained was soft and easily removed with a scraper. The pistons were then cleaned, the head replaced and the test continued. With the completion of tne prescribed 2,500 miles I again exam:ned
the cylinder head, valves and pistons, and found a marked absence of carbon throughout. A check was to have been made of the petrol consumption, but unfortunately, owing to carburettor trouble, which entailed the installation of a new instrument midway through the trial, this was not possible. The cartridges last several hundred miles, and in my test seven were uses
On the same car I have also had fitted a set of Super Suspension spring attachments, which consist of a number of steel plates housing steel balls. These are inserted between the spring leaves, so that their action increases the freedom of movement between the individual leaves, and so increases their periodicity. Under test I found the car when equipped with this device decidedly more comfortable, and after making the necessary adjustment to the shock absorbers there was a definite improvement in control at high speed and the road holding qualities. The steering, according to another member of the MOTOR SPORT staff, was also lighter than before, and, contrary to our expectations, over really rough surfaces there was no tendency towards excessive wheel bounce or undue swaying in fast corner work.