I am an engineer connected with the engine industry, and am interested in internal combustion engine history and development.
Here in England many societies, clubs, and individuals are actively engaged in the acquisition, restoration, and preservation of steam traction engines, road rollers, etc., but by comparison with the activities of gas engine enthusiasts in the United States, little has been seen of such activities in England. There are a few people here with good collections of old farm tractors, but it would appear that war time scrap drives eliminated vast numbers.
In 1964, I purchased a 1933 10 ton oil engined road roller. Although this machine is relatively modern, it is almost unique, as its power unit is a single cylinder Blackstone oil engine. This roller was probably one of the last to be produced by Aveling and Porter of Rochester, before amalgamation with Barford Perkins of Peterborough, to form Aveling Barford Ltd of Grantham.
The engine of the roller is quite large, of 7-inch bore and 14-inch stroke, built on gas engine principles. The connecting rod and crank are enclosed by a sheet metal cover.
The engine is in fact a low compression diesel, starting from cold being assisted by an igniter. Rotation of the engine for starting is produced by compressed air stored at 400 PSI in seamless bottles which are refilled by back charging from the engine.
Fuel is injected by Carters patent spring injection system, consisting of the injector block mounted on the cylinder head, and a low pressure metering pump operated by an eccentric on the camshaft.
The centrifugal governor is driven by skew gears from the camshaft, and it controls the effective stroke of the metering pump plunger. Gas oil from the metering pump is discharged into a spring-loaded accumulator cylinder in the injector block, then the operator uses a crank on the end of the camshaft to wind the accumulator spring, creating injection pressure of about 1,000 PSI. At 15 degrees from T.D.C. a toppet relieves part of the load on the injector needle valve, permitting fuel to be injected.
The engine is lubricated on the total loss system by a 4 point lubricator with sight glasses: 2 points feed the liner, 1 point feed each main bearing, and excess oil is collected by banjo rings and fed to the big end. I use an H.D. 30 oil.
The engine is cooled from a 120 gallon water tank under the footplate. A plunger pump operated by an eccentric on the camshaft circulates the water.
The exhaust is conducted up a steam engine-type chimney; when I take this machine to steam rallies, many people wonder where the fire-box is!
The engine speed can be varied between 130 R.P.M. idle to 350 R.P.M. maximum by a hand wheel operated from the footplate, which controls the load on the governor spring. The engine develops approximately 20 BHP at 350 R.P.M.
The drive is taken from the engine by a duplex chain to the gear box input shaft, through either the forward or reverse cone clutch. The gear box has three speeds, giving 4 mph in high, 2 mph in second, and 1 mph in low.
I purchased the roller in rough although running order, and was helped in its restoration by members of the Colchester Society of Model and Experimental Engineers. The cylinder liner is badly worn, but I have considerably improved the power by detailed attention to the fuel injection equipment and fitting new piston rings.
During the last two years, I have attended several steam engine rallies with the roller. It has attracted a great deal of interest, and gives rise to most interesting comment.
I have traveled about 100 miles on the road with it to these rallies. Gas oil consumption is about 7 mpg. Running light, the engine burns one gallon in four hours.
There are not many stationary gas engines in preservation here. The only engines I have seen have been a Fairbanks Morse and an Amanco.
I was most interested to see that Gas Engine Magazine is preparing an article on the Hornsby Akroyd engine, as I have recently found a 1907 6 HP Hornsby engine, No. 29270, belonging to Mr. S. Hills, of West Mersea, Essex, and am endeavoring to mount it on a trailer so it can be taken to traction engine rallies. I have obtained information from Ruston & Hornsby Ltd., and am enclosing with this article photostat copies of the instruction book and parts list.
These engines were manufactured under license by the De la Vergne Co., of New York; Manufacture of these engines in England continued until 1920.
The photograph of the roller on the front of the April-May 1967 G.E.M. was most interesting, as many features on this machine are similar to Blackstone engined rollers manufactured by Aveling and Porter, between 1926 and 1932.