The Marlin-Rockwell Corp., of New Haven, Conn., shortly expects to put on the market a stationary airplane engine of the two-cylinder horizontal opposed type which has been developed by J. L. Cato, formerly experimental engineer  
Marlin-Rockwell Engine
Marlin-Rockwell Engine
of the L-W-F Engineering Corp., and is illustated herewith in front and rear views.
     This engine, which has been designed for use in a small sporting monopalne now being developed by Mr. Cato, has in its initial tests given 72 hp. at 1,825 r.p.m., and weighs well under 2 lb. per hp. Mr. Cato also intends to develop the same design into a 10-cyls. radial engine which is to develop 500 hp. and weigh about 1 1/2 lb. per hp.
from Aviation and Aeronautical Engineering
May 15, 1919, page 436
Courtesy of Albert M. Rockwell, Jr., 1-28-05

by Albert M. Rockwell, Jr., 1-29-05
     Hugh Rockwell developed this engine, with its' anti-friction bearings, and the monoplane at Liberty Field in 1917 according to my father. (See his note on the envelope that contains pix). He always said it is a 60 horsepower engine.
      Cato's 5" bore, 6" stroke engine with anti-friction bearings was a later version of this engine, which corrected the cylinder stud deficiency. Notice also that he deleted the cylinder ports in his late 1919 engine at LWF.

     "3/4 view of the Cato Ball Bearing Light Plane motor. There was not a plain bearing in this entire motor. This motor is 5" bore x 6" stroke. developes 72 H.P. and weight was 133 lbs. it was the largest bore air-cooled motor to successfully fly a plane in the day and to keep cool. the cyl. head design of this motor has set a standard for all air-cooled motors in use today."
Text on back of photo written by J. L. Cato, 1919
Courtesy of Phyllis Cato Ferguson

  Editor's Note: The motor pictured above may not be the one Hugh built, but is probably similar in construction. It is Al Rockwell, Jr's. opinion that Cato's engine is a later version of the original Hugh Rockwell engine. For more details, see below.  

Joseph Cato, Marlin-Rockwell and Old Airplanes
via email from Al Rockwell, Jr., 1-5-05
     Several years ago I contacted CAHA, (Connecticut Aviation Historical Assocation), about my great-uncle's engine. They had come up with a couple of 2 stroke target drone engines only. This engine was much larger. They indicated to me at that time that there were a lot of un-inventoried items in storage. I did not pursue it further then.
     I know for sure that my father donated that engine along with magnetos and other accessory parts and a .50 cal. aircraft wing gun to CAHA by way of Harvey Lippincott, who he was good friends with. (I remember Harvey had a son, Bruce, with whom I've also lost contact).
     I remember the Browning patent machine gun was made by High Standard. My grandfather had it in his possession as he did munitions development work at Indian Head Proving Ground in the 1918 period.
Hugh's Plane 2
Hugh's Airplane, Photo 2
One of the three which were in an envelope from Albert M. Rockwell, Sr.,
while he was at P & W.A.
Scanned by Albert M. Rockwell, Jr., November 14, 2004
       More recently I have a renewed interest in the engine. I now have several photos of my Great Uncle Hugh's airplane & engine in an envelope notated by my father when he worked at P&WA Engineering 2N in the '50's. (I think Dad's P&WA badge no. was 412. He retired in the '80's and is deceased). The engine can be seen in one or two pix, but not too clearly.
     To my best recollection, his two cylinder opposed engine that I took apart was perhaps 36 inches from head to head. I recall that it was probably a developmental engine, as I remember the engine having one large valve centered in each cylinder head. As I saw only parts of a manifold system of some type, I don't know the exact induction/exhaust system he had in mind.
     The one I know Hugh actually flew had a more standard type of rocker arm, pushrod, two valve head configuration, but appears otherwise similar. I also recall band clamps covering round ports around the cylinder walls and just below the fins that would have been exposed when pistons were down. I think I can see these ports, uncovered, in a photo. A couple of other features I vaguely remember were thin wall cylinders, machined all over with fine fins on close spacing, and four long studs each that went from the heads to the crankcase thru the cylinder fins to secure the heads and cylinders, as VW has in their classic. I remember them being only about 7/16" dia. (See dad's discussion on back of formal picture of Hugh, noted a number of years ago and draw your own conclusion)!
     It was in the '50s that I disassembled this engine in our home garage in Glastonbury, Connecticut, where I grew up. Having a fourth generation interest in mechanical things and particularly ball bearings, (My great-grandfather founded New Departure), I was very interested in the unique innards of the engine.
     I was fortunate to have a few features pointed out by my dad, which I remember quite well. The engine, made in about 1916 had Lynite pistons, a five inch bore and six inch stroke. He said he believed the specific bore was arrived at to take advantage of the fact that pistons did not have to be developed, being Liberty engine items. He showed me the unique antifriction bearings on the crankshaft and both ends of the connecting rods.
     The wrist pins were themselves the inner races of needle (or skinny roller) bearings. The rod upper end bores were themselves the outer wrist pin bearing races. the roller cages were machined from aluminum in two halves that were assembled from the ends of the rollers. Their wall thickness was not much less than the roller diameter if I remember correctly.
     The crankshaft bearings were likewise integral to the crankshaft. The inner ball bearing races were ground directly into the crankshaft. The outer races and balls were assembled together onto the crank. I vaguely remember loading grooves, as are typical for full complement bearings.
     A primary design consideration in the design of opposed engines is to have the centerlines of opposite cylinder pairs as close as possible to each other to minimize rocking couple. The antifriction connecting rod "big end" bearings in this engine accomplish this in an elegant way.
     As they are internal, the above features don't help identify the engine without opening it up, so the unique rod journals and bearings don't need to be discussed here. They are a subject on their own which I'll discuss, along with some other facts, if you think you've found a possible engine, or even a solid lead to one!
     Incidentally, if you've found what you think is an early 1919 or before Cato engine, don't hang your hat on that identification. In reviewing my great-grandfather and his sons during the course of researching Rockwell genealogy, I have found out several facts that say you probably found Hugh's engine if drawbolts held the heads down. Cato's later versions of Hugh's engine had cylinders held in place by perhaps 8 or 12 bolts thru cylinder flanges fixing the problem dad wrote about. This can be seen in "his" LWF engine of late 1919 or early '20. You can also see lack of the ports below the fins.
     I sure hope you can help me locate this engine so we can contribute some historically accurate details
     Send me a direct mailing address and I'll snail mail you pix, including the mentioned notes.
Thanks a lot for your interest!
Al Rockwell (Jr.)
399 South Road
Belmont, Ca. 94002-1912 (650)591-9543

Hugh's Engine
via email from Al Rockwell, Jr., 1-5-05
     Hi again, Ralph, I'm not aware of the fellow you mentioned as having developed the engine. To the best of my knowledge, the engine was developed by Hugh M. Rockwell. Perhaps they worked together. Don't forget, Hugh was the one with the anti-friction bearing contacts, background and expertise, I have a formal picture of him, on which my father, his nephew said he had returned to Bristol Airport, (Where Superior Electric is now) with a cylinder head dangling from a plug wire.
      I suspect that the engine or at least parts may have been constructed at E. A. Rockwell automotive engineering lab in Long Island, also of which I have photos.
     I personally disassembled and reassembled one of Hugh's experimental engines in about 1958 or so, before my dad and I donated it to the Connecticut Aeronautical Historical Association. I can tell you first hand, that Hugh's engine had anti-friction bearings thruout, even as far as the wrist pins! I'm trying to see if I can find out what NEAM, who took over CAHA might have done with it. CAHA founder, Harvey Lippincott and my dad were good friends.
     My dad was a P&WA employee, no. 412, as I recall. He worked there all his life, thru being a design chief in the era of the radials. His real love was gearing. At one point, while at PWA, he tore down, documented and reassembled the Wright Flyer engine for the Smithsonian.

BackBack Home