The Crosley Quicksilver Engine
With The Thompson Vitameter


The VITAMETER is a simple precision instrument developed by Thompson Products, Inc. for high compression engines requiring high octane fuels for their proper performance.

It is a well known fact that all of the advantages of high compression engines have been limited heretofore by the type of fuel readily available to motorists. In recent years, prior to the development of the Korean situation, gasoline octane rating has been stepped up from time to time permitting higher and higher compression ratios. The indication is now that war conditions must necessarily force down the octane rating of motor gasolines.

The Vitameter automatically supplies Vitane, a properly balanced fluid containing alcohol, water and tetraethyl lead, to the carburetor air inlet where it combines with the gasoline mixture only when needed to prevent detonation, pre-ignition and consequent knocking. Thus engines which can run without this objectionable knocking or pinging on a fuel of a given octane rating can also function perfectly with sub-octane rated fuels. In practice the Vitameter raises the effective octane rating of any gasoline with which it may be used by at least ten octane numbers.

Now there is available a specially designed Vitameter to fit the startlingly flashy performing Crosley over-head camshaft, valve in-head engine. This Crosley engine is recognized for its ability to run with higher compression ratio on ordinary fuels than any other American automobile engine. The standard compression ratio in Crosley cars is 7.8 to 8:1. It will operate perfectly with ordinary non-premium fuels. This is the highest standard compression ratio in the field.

The Vitameter now makes it possible to step up the compression ratio to a new and startling high of 10:1 (plus or minus for production tolerances). Without the Vitameter this compression ratio, even in the Crosley engine, would require gasoline with an octane rating close to 100, which, of course, is not available to the average motorist, if available to any.

Thanks to the Vitameter, Crosley is now making available in a certain model or models this 10:1 compression ratio in combination with the Vitameter and the use of Vitane. Vitane contains highly effective anti-knock compounds plus all the ingredients that were used during the war for alcohol-water injection, which was so successful in our fighter planes and is also being used in commercial planes of high performance characteristics.

The operation of the Vitameter permits the introduction of the Vitane into the gasoline mixture primarily under conditions of wide-open throttle and low engine speeds. This operation is regulated by the vacuum in the carburetor venturi and in the intake manifold; as the engine speeds up or the throttle closes, the flow of Vitane is discontinued. The period when the Vitane is used is simultaneous with the period when the pinging or knocking in an engine would occur. As the revolutions of the engine increase or the load lightens, the Vitane is not required; through the design of the Vitameter a perfect balance is maintained whereby the Vitane solution is used only during the period when it is necessary to prevent pre-ignition, detonation or knocking. The Vitameter also is shut off at higher speeds even though the throttle is wide open.

The proportion of Vitane to the amount of gasoline used ranges from 20% during the short period when high knock characteristics might be expected, to no Vitane at all during the period when the engine would not knock anyhow. In practice use with many starts and stops, such as in city driving, Vitane consumption might be expected to be about one gallon to six hundred miles of such use. For country driving, on the other hand, the use of Vitane should be expected to fall to one gallon for 2,000 miles. These figures on consumption are given from actual tests in connection with a 10:1 compression ratio Quicksilver engine in a Crosley super-sports car using ordinary non-premium pump gasoline.

The Vitameter is of little value in any car that does not knock or ping from the fuel that is being used in it. Therefore, the Crosley special Vitameter cannot be recommended as being of value to the user of a standard Crosley engine, but the Vitameter does make possible the Crosley 10:1 Quicksilver engine with good regular grade gasoline. In some areas regular grade gasoline may not be high enough in octane rating, making it necessary to use premium gasoline or to retard the spark slightly to avoid knocking or pinging.

The Vitameter is warranted only when used with Vitane; do not use water, antifreeze or other substitutes as this may cause corrosion of the engine and other vital parts.

The Vitameter has been designed by Thompson Products, Inc, Vitameter Division, for the Crosley 10:1 compression ratio Quicksilver engine and is exclusively distributed by Crosley Motors, Inc.

The Crosley 10:1 compression ratio Quicksilver engine gives additional horsepower, better hill climbing, higher speed, and, at any given speed, greater economy in spite of the additional cost of the Vitane fluid.

The Vitameter makes possible the souping up of the Crosley engine for racing purposes without the use of special or sometimes illegal fuels.


Crosley Motors Inc
2530 Spring Grove Avenue
Cincinnati, Ohio

Text from a factory flyer.
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