Waaaaaaaaaay back to the beginning

[Mark75H]

The third Johnson was their grand master piece ... the TR-40 "Giant" Twin racer. Again, a 2 cylinder opposed 2 cycle with piston port intake. The Giant Twin truely was giant at 49 cubic inches. Putting out a whopping 25 3/4 hp it was a bit too much for the streamlined racing lower unit they built for it and was a little lacking on the endurance side of things. Only a few examples of the TR-40 survive today.

Mechanically the Johnson racers differed from their fishing stable mates by being equipped with narrower streamlined lower units with gear ratios allowing the propellers to turn faster, and pistons made from light weight aluminum instead of cast iron. The lighter pistons allowed the motors to rev up 500 to 1000 more rpm and make a little more power. Johnson parts books also show different part numbers for P40 and PR40 cylinders. Even though they appear the same on the outside, they are quite different internally, giving the racer a much higher compression ratio and larger exhaust ports. The early TR40's and PR40's used the same bronze connecting rods as the fishing motors, but later in 1928 they switched to a light weight steel connecting rod with roller bearings on the “big” (crankshaft) end. The KR40 fit in class A, the PR40 in class C and the TR40 in E.

I'll try to dig up some photos of these early Johnson racers.

[Mark75H]

Caille updated their racer as the Model 30 in 1928

The Model 30 was the last Caille to carry the air shutter extra air inlets. The carb was set pretty rich to make starting easy and was small-ish to allow reasonable low rpm operation. Once you were warmed up and going you could open 2 little extra air shutters on the intake manifold to let in more air and go faster. This probably worked better than a larger carb would have worked given the 1920's carb technology.

[Mark75H]

Ole Evinrude had been making a 4 cylinder opposed motor for a few years and in mid 1928 came out with a racing version of it as the "Hi Speed Quad" ELTO (Evinrude Light Twin Outobard).

Though not explicitly advertised and sold as a racing only motor, the "Hi Speed Quad" model 308, did quite well as a racer. Actually the 308 model number was given later probably when ELTO was consolidated into OMC. All the Quads used four separately cast cylinders on a common crankcase with the center main bearing dividing them in to two chambers. Each crankcase chamber had its own Tillotson carb. Battery ignition made by Atwater Kent provided spark from two front mounted ignition coils. The speedy new ELTO used light weight “Lynite” aluminum pistons and connecting rods instead of the standard Quad's cast iron pistons and rods. To reduce friction the Hi Speed Quad used 1/8 inch wide piston rings compared to the standard 3/16 rings. The streamlined lower unit used 16:24 gears and the housing was two pieces bolted together, split horizontally. This motor was rated at 18 hp at 4800 rpm. At 39.9~ cubic inches this motor fit in class D.

[Mark75H]

Here's an example of why you should be a member of the Antique Outboard Club of America if you are at all interested in these old motors. This is a picture from the club's private "inner sanctum". This is just one of many images of remarkable resorations of old and rare "old iron"

[Mark75H]

Lockwood had 2 models that won a lot of races in the mid 20's without being special racing motors. Other companies' racing models already mentioned may have been made to try to keep up with Lockwood's standard models:

[Mark75H]

Lockwood Chief

[Peter Crowley]

Lockwood came out in 1928 with a new pair of models. The ACE was an A class engine and the CHIEF was a B class engine. Both dominated the record books that year (1928) in these two classes. The real secret to Lockwoods success was the young mechanical engineer Finn Irgins. He was one of the leading two-stroke engine experts of the time.... In fact being able to secure his services was one of the reasons that Evinrude/ELTO purchased Lockwood in 1929. For that year (1929), Lockwood mostly left the ACE and CHIEF engines alone (except for an underwater exhaust). The ACE still continued to dominate in the A class for 1929 only. Lockwood produced a special "Racing Chief" engine with many racing feartures. It drew attention because of its round red gas tank. On the practical side, it had dual carburetors, a lightweight flywheel and an added oiling system that featured glass "oilers". It was limited production, but even this special engine wasn't enough to be as competitive as it was the year before with their production engine! In 1929, Lockwood was developing an engine that would later become the Evinrude 4-60. Finn soon became chief engineer at OMC and worked shoulder to shoulder with Ole Evinrude.
With several manufacturers all developing engines for racing, it wasn't surprising that an engine quickly became obsolite after a single season. Increases in horsepower grew with every offering.

[Mark75H]

Thanks, Peter!

2 carbs, the smaller flywheel off of the 1928 Ace, the red gas tank
look closely between the flywheel and the gas tank and you will see a glass cylinder with brass top and bottom. That is the oil resevoir to directly lubricate the bearings, that Peter has mentioned.

.... I'm sure "Irggy" put more goodies inside than out.

The 92BR has very distinctive squarish intake horns in front of the carbs.

Power was increased from 11hp at 4,200 rpm to 14 hp at 4,800 rpm

The 92BR weighed about 75 pounds

This 92BR belongs to Mike Lynch:

[Mark75H]

Happy owner of a Racing Chief

[Mark75H]

In 1929 Caille had 2 racers in the stable. The model 34 "Champion" replaced the model 30.

The Champion claimed 14 hp at a remarkable 6,500 rpm.