US3131677A - Fuels for internal combustion piston engines and to the operation of such engines - Google Patents

Description

United States Patent 3,131,67 7 FUELS FOR ltNTERNAL CQMBUSTION PISTON ENGINES AND TO THE ()PERATION OF SUCH ENGINES Horace John Eatwell and Stanley Thomas Walker, Sunhury-on-Tharnes, England, assignors to The British Petroleum Company Limited, London, England, a jointstock corporation of Great Britain No Drawing. Filed Jan. 13, 1960, Ser. No. 2,117 Claims priority, application Great Britain Jan. 14, 1959 9 Claims. (Cl. 123-1) The running-in of internal combustion piston engines has always presented a problem. In the case of gasoline engines and small diesel engines such as are used in road vehicles, no satisfactory method has been developed for running in the engine quickly and, because of the time that it takes to run the engine in under normal operating conditions, it is not usually economically practicable for the engine or vehicle manufacturers to run the engine in before the vehicle leaves the factory Where it is manufactured.

While the engine is being run in it is important that its speed be kept below a certain value and the running-in of the engine should be continued until the oil consumption reduces to a steady level which may be in excess of 10 hours. Failure to observe these precautions is likely to result in serious damage to the engine particularly to the piston rings and cylinder walls.

In the case of larger diesel engines, i.e. medium and slow-speed diesel engines, it is customary to run the engine in before it goes into normal service. The only commercially used accelerated running-in procedure for such engines involves the use of a naturally occurring volcanic ash which is fed into the engine cylinder with the air supply and which acts as an abrasive and so causes rapid wearing of high spots on the piston rings and cylinder. This procedure however suffers from a number of. drawbacks. For example, the quantity and consistency of the material being supplied to the cylinder has to be carefully controlled otherwise serious damage may occur; it is not always possible to use the procedure in multicylinder engines.

It has now been found that the running-in of piston engines can be quickly and effectively carried out by running the engine for a short time on a fuel containing a particular additive.

According to the invention, a fuel composition suitable for use in running-in an internal combustion piston engine, consists essentially of a fuel suitable for operating such an engine, e.g. a gasoline or a diesel fuel, and having dissolved therein a minor amount, preferably O.l%, e.g. 0.25 %-2.5%, by weight, of an oil-soluble aluminium compound which can be converted to the oxide by heating. The term oil-soluble is used in the sense that the compound must be capable of remaining in stable suspension in the fuel and not separate out on storage. Thus the compound may be present in the fuel in the form of a colloidal suspension.

A preferred class of aluminium compounds are polymeric organic aluminium compounds of the general formula O Al X where X is an acylate group (i.e. a group having the formula RCOO-where R is an aliphatic or aromatic hydrocarbon or substituted hydrocarbon radi- 3,131,677 Patented May 5, 1964 ICC cal), m, n, and p are integers, m is not less than 2, m/n is 0.75-2.0 and m/ p is 0.5-3.0. It is to be understood that the acylate groups in any given molecule of the additive may be the same or different.

Preferred additives are those of the formula (OAIX) where q is an integer greater than one, preferably 2-10, especially 3. The acylate groups are preferably those of the formfula RCOO-where R is a saturated or unsaturated alkyl or aryl radical containing 6-30 carbon atoms. Particularly preferred are the acylate groups derived from benzoic or salicylic acids, or aliphatic monocarboxylic acids having 12-20 carbon atoms, e.g. stearic or oleic.

ne polymeric organic aluminium compounds referred to above are commonly described as polyoxo-aluminium acylates. They may be prepared by heating aluminium alcoholates with water and carboxylic acids in one or more stages and preferably in an inert, non-volatile diluent such as a light lubricating oil. This method of preparation is described in the specification of U.K. Patent Specification 825,878. Alternatively, they may be prepared by heating aluminium alcoholates with carboxylic acids alone so as to liberate alcohol and form acyloxy aluminium alcoholate compounds, and further heating the latter compounds. This method of preparation is described in the U.K. Patent Specification 806,113.

Certain of the aluminium additives are available commercially under the trade name Manalox. One such commercially available material (hereinafter called additive M) is believed to consist of a solution in one part by weight of iso-propyl oleate of one part by weight of a material of the formula (OAlOCR where R is an oleyl radical. It was prepared as follows: One molecular proportion of aluminium isopropoxide was reacted with two molecular proportions of commercial oleic acid at a temperature increasing to about 220 C. Two

molecular proportions of isopropanol distilled ofi during the reaction, a slight vacuum being applied near the end of the reaction to aid the removal of the last traces of isopropanol.

Another class of oil-soluble aluminium compounds which are suitable for use in the fuel compositions according to the invention are aluminium glycolates.

The invention also consists in a method of running-in an internal combustion piston engine which comprises running the engine on a fuel as hereinbefore specified, preferably until the oil consumption of the engine has fallen to a substantially steady level.

A number of examples of the invention will now be described.

Example 1 A single cylinder 550 cc., gasoline engine, fitted with a radioactive piston ring, was run on a commercial grade motor gasoline (boiling range 42.5 to 164 C.) containing 2% by weight of additive M. The engine was operated at 1500 rpm. which is considered to be a good normal running-in speed for such an engine. The wear of the piston rings (as measured by the radioactive tracer technique) took place at a steady state which was 2000 times the wear rate when running the engine under identical conditions with the same gasoline not containing the additive M. This result indicates the the use of the additive M in the fuel would accelerate the running-in of a gasoline engine very considerably.

Example 2 Fuel D1:A commercial diesel fuel of boiling range 195 to 351 C.

Fuel D2:Fuel D1 containing 1% wt. additive M.

Fuel D31Fuel D1 containing 0.5% wt. additive M.

The wear rate of the piston rings when using Fuel D2 was up to 50 times and, when using Fuel D3, up to 25 times the wear rate when using Fuel D1.

The amount of piston ring wear when operating the engine for a period of 2 hours on Fuel D2 was equivalent to the amount known to be necessary for satisfactory running-in of the engine in the normal way using a fuel such as D1; normal running-in usually takes about 50 hours. It can therefore be deduced that the use of 1% wt. of the additive M in the fuel reduces the running-in period of the engine from 50 hours to 2 hours.

Example 3 A 550 cc., single cylinder, trunk piston, medium speed diesel engine fitted with a new liner, piston and ring assembly was run at 1500 r.p.m. for 2 hours using a commercial diesel fuel of boiling range 195 to 351 C. and containing 1% wt. of additive M.

At the end of this running time the oil consumption was similar to that after about 50 hours running-in with the untreated fuel. From this it can be deduced that the use of 1% wt. of the additive M in the fuel reduces the running-in period of the engine from 50 hours to 2 hours.

Example 4 A 1400 cc., single cylinder trunk piston, medium speed diesel engine fitted with a rehoned liner and a new piston and ring assembly was run at gradually increasing loads and speeds up to the maximum rated output of the engine (16 brake horse power at 1500 r.p.m.) for 2 hours using a commercial diesel fuel of boiling range 195 to 351 C. and containing 0.5% wt. of additive M.

At the end of this rtmning time the oil consumption was similar to that obtained after a six-hour run-in using conventional methods.

Example 5 A 3400 cc., single cylinder, trunk piston, medium speed diesel engine of the type used in large earth moving equipment, and fitted with a new liner, piston and ring assembly was run at gradually increasing loads and speed up to 20 brake horse power 'at 1000 r.p.m. for 2 hours using a commercial diesel fuel (boiling range 195 to 351 C.) and containing 2% wt. of additive M.

At the end of this running time the oil consumption was less than that obtained by using an abrasive powder to accelerate the run-in. It is normal practice in this particular engine to use a specified abrasive powder during the run-in period, because by merely running the engine it can take up to 500 hours before a satisfactory stable low oil consumption is obtained.

Example 6 A 250 cc., single cylinder, trunk piston, high speed gasoline engine fitted with a new liner, piston and ring assembly was run at gradually increasing speeds and loads up to 2500 r.p.m. and 46 brake horse power for 2 hours using a commercial gasoline (boiling range 42.5 to 146 C.) containing 0.5% wt. of additive M.

At the end of this running time the oil consumption was one half of that obtained after a normal 8 hour run-in period.

Example 7 The engine used in Example 6 was run under the same conditions, but the gasoline contained 2% additive M.

At the end of this running time oil consumption was one fifth of that obtained after a normal 8 hour run-in period.

by wt. of

Example 8 A 2180 cc., four cylinder, trunk piston, high speed gasoline engine fitted with rehoned liners, new pistons and ring assemblies was run at gradually increasing speeds and loads up to 3500 r.p.m. and 60 brake horse power for 2 hours using a commercial gasoline (boiling range 34 to 186 C.) containing 0.5% wt. of additive M.

At the end of this running time the oil consumption was similar to that obtained after a normal 8 hour run-in period.

It will be appreciated that the short time that it takes to run in an engine when using the fuel or method according to the invention makes it very much easier and more economically feasible for engine and vehicle manufacturers to run-in engines before delivery of the engines or vehicles.

The effect of using the polymeric organic aluminium additives above specified in fuels for internal combustion piston engines is very surprising because the same additives when used in lubricating compositions for the cylinders of diesel engines operating on high-sulphur fuels are very eifective in reducing the high cylinder wear rate normally associated with the use of such fuels. It is believed that the effect of using the additives in fuels is due to the fact that under the conditions prevailing during the combustion of the fuel in the engine cylinders the aluminium compounds break down into a highly abrasive form of aluminium oxide.

We claim:

1. A fuel composition suitable for use in running-in an internal combustion piston engine, said composition consisting essentially of a fuel suitable for operating an internal combustion piston engine and said fuel being selected from the group consisting of gasoline engine fuels and diesel fuels and having dissolved therein 0.l5%,

by weight of the composition, an oil-soluble aluminium compound which may be converted to the oxide by heating, said compound being a polymeric organic aluminium compound of the general formula (OAlX) where q is an integer from 2-10 and X is an acylate group having the formula RCOO, Where R is a substance selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons and substituted hydrocarbon radicals.

2. A fuel composition according to claim 1, in which the amount of said aluminium compound is 0.252.5%, by weight of the composition.

3. A fuel composition according to claim 1, in which q is 3.

4. A fuel composition according to claim 1, in which the acylate groups in said aluminium compound have the formula RCOO, where R is a radical selected from the group consisting of alkyl and aryl radicals having 6-30 carbon atoms.

5. A fuel composition according to claim 4, in which said acylate groups are derived from at least one monocarboxylic acid selected from the group consisting of benzoic, salicyclic, and aliphatic monocarboxylic acids having 12-20 carbon atoms.

6. A fuel composition according to claim 5, in which said aliphatic monocarboxylic acids are stearic and oleic acids.

7. A fuel composition according to claim 6, in which the said aluminium compound has the formula (OAlX) where X is an acylate group derived from oleic acid, the amount of said aluminium compound in said fuel composition being 0.252.5% by weight of said composition.

8. A method of running-in an internal combustion engine which comprises running the engine on a fuel composition according to claim 1.

5 6 9. A method according to claim 8, in which the engine 2,744,074 Theobald May 1, 1956 is run until the oil consumption of said engine has fallen 2,851,417 Andress Sept. 9, 1958 to a substantially steady level. 2,902,983 Patberg Sept. 8, 1959 References Cited in the file of this patent 5 5 9 FOREIGN PATENTS N 26 1931 3 ,494 Germany 0v. UNITED STATES PATENTS 1,076,375 France Apr. 21, 1954 3323 33 3 :32; 795,658 Great Britain May 2 8, 1958 yons e 2,546,421 Bartholomew et a1 Mar. 27, 1951 10 OTHER REFERENCES 2,575,003 Caron et a1 Nov. 13, 1951 The Condensed Chemical Dictionary, fifth edition, 2,739,049 Massa et a1 Mar. 20, 1956 Reinhold Pub. Co., 1956, page 52.

Patent No. 3,, 131,677

May 5, 1964 Horace John Eatwell et a1.

It is hereby certified that ent requiring corr corrected below.

error appears in the above numberedzpatectio'n and that the sa id Letters Patent should read .as

Column 2 line 8, for "formfula" read formula line 31 for "(OAIOCR Signed and sealed this 22nd day of September- 1964.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attcsting Officer Commissioner of Patents

Claims (1)

1. A FUEL COMPOSITION SUITABLE FOR USE IN RUNNING-IN AN INTERNAL COMBUSTION PISTON ENGINE AND SAID FUEL BEING SELECTED FROM THE GROUP CONSISTING OF GASOLINE ENGINE FUELS AND DIESEL FUELS AND HAVING DISSOLVED THEREIN 0.1-5%, BY WEIGHT OF THE COMPOSITION, AN OIL-SOLUBLE ALUMINUM COMPOUND WHICH MAY BE CONVERTED TO THE OXIDE BY HEATING, SAID COMPOUND BEING A POLYMERIC ORGANIC ALUMINUM COMPOUND OF THE GENERAL FORMULA (OAIX)Q, WHERE Q IS AN INTEGER FROM 2-10 AND X IS AN ACYLATE GROUP HAVING THE FORMULA RCOO-, WHERE R IS A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC HYDROCARBON, AROMATIC HYDROCARBONS AND SUBSTITUTED HYDROCARBON RADICALS.