Injector pump

3: View of model showing injector pump, pump valve and governor.

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3 Edna Terrace New Hartford, W 13413 hitnmiss@juno. com

Subject: Springfield Type 'A' 1 HP








36' overall




140 lbs.


150-500 RPM


$5750 Finished, $4750 Painted.


Wayne Grenning, Grenning Models, 3678 N Ridge Rd, Lockport, NY 14094


No longer in production. 2-3 still available as of 3/99

1: ? scale model

1: ? scale model, Springfield type 'A' 1 HP.

Springfield type

2: Springfield type 'A' 1 HP on display at the Coolspring Power Museum.

3: View of model showing injector pump, pump valve and governor.

As a longtime fan of old iron and a student of prime mover mechanisms, I have come to appreciate the effort that goes into the design and implementation of scale models of the engines that drove the industrial revolution. There are a few fine machinists who create replicas of the old time engines in quantity, and offer the fruits of their labors for others to purchase and enjoy. The subject of this article blows them all away (picture 1).

This model is a very nearly exact scale replica of the much coveted Springfield Type 'A' 1 HP engine. It was modeled after the 1900 vintage engine currently on display at the Coolspring Power Museum in Coolspring, PA (picture 2). The Springfield Type 'A' is considered the first overhead cam engine with fuel injection. It features an angled sideshaft to drive a cross shaft which has cams for the intake valve, exhaust valve, auxiliary intake valve, ignitor, and fuel injector pump and valves. The governor also spins on the cross shaft, but is independent of the shaft, and is driven by a leather belt from the crankshaft (picture 3).

The engine is mostly cast iron, with cast brass, iron and steel running gear. It comes complete with brass plumbing, functional (but unnecessary) brass cooling tank, all mounted on a sealed oak base (oddly, the original 1 HP Springfields were not offered as portables). The material and workmanship is better than many one-off models, yet over 50 of them were made. Each engine has at least one hour of run time on it before it is shipped. All that is needed is a bit of gasoline with a little two cycle engine oil to keep the injector pump happy, a battery, small coil, and you are ready to go. Coleman fuel is NOT recommended. The engine is fairly low compression, and is very easy to start. It will run all day on ? tank of gas. For starting, there is an air restrictor that is placed over the end of the intake. It is not a choke, since it doesn't pull fuel through the engine. It just restricts the air. To start, the fuel shut-off is opened, and the battery and coil are attached. The fuel line is then bled through the drain valve. The restrictor is placed in the air intake. The adjustment that controls the pump stroke is backed off for a richer starting mixture. A few quick flips, and away she goes! After the engine is good and warm, the restrictor is removed and the plunger is adjusted so that the engine runs lean while not missing any fires. Cooling water is not needed if the engine is run slow and not loaded. It will run all day and just get a little warm. A personalized, 29 page, spiral bound instruction book is included, which covers care and feeding. It also has pointers for those of us who can't resist tinkering with our toys, and for the folks who order the unfinished version. Although the engine is a hit and miss type, it is not a conventional pick blade arrangement. Not in the least! Referring to picture 4, on the left of the cross shaft is the bevel gear for driving. Next is the exhaust valve, which is pretty conventional. In the middle is the ignitor actuated by a snap eccentric from the cross shaft. There is a ratchet on the snap eccentric, as on the original, that prevents destruction of the ignitor trip in the event of a backfire. The main intake valve is also fairly conventional, and is just to the right of the cylinder. The belt driven governor assembly is to the right of that. Next is an auxiliary intake valve, which is opened when the governor allows the engine to fire. Above that, on the cross shaft, is a cam to actuate the fuel pump, and another cam on the same assembly which throws the pump plunger out of action when the engine overspeeds. The end of the cross shaft has a snap eccentric for operating the fuel pump valve.

4: View of the back of the engine showing the cross shaft.

5: 2 cylinder Springfields

5: 2 cylinder Springfields.

Otto-Langen atmosphere engine

6: Improved model of the Otto-Langen atmosphere engine.

Fuel is fed to the pump by gravity from the galvanised tank through the valve to the pump. The pump plunger is timed to inject a metered quantity of fuel into the intake gooseneck during the intake stroke. The stroke of the plunger is adjustable to meter the correct amount of fuel. The plunger is actuated by a cam which acts on a catch block, which is pivoted and spring loaded. The block mates to another catch block which actuates the plunger and opens the auxiliary intake valve. When the engine goes over its rated speed, the governor moves a cam into position, which pivots the first catch block such that it no longer engages the second one. The engine misses until the engine falls to its rated speed. The governor moves the cam out of the way, the catch catches, and the engine gets another charge.

Once again, Mr. Grenning has brought us a very unique model. The only non-scale thing about it is probably the tolerances and level of finish are much better than scale. It is a bit on the heavy side. At 140 pounds, it is just slightly too heavy for one person to carry. The price may also seem high for most folks, but if you have ever priced a full sized Springfield type 'A' of any HP, you know that this is a bargain!

Picture 5 shows a pair of 2 cylinder Springfields made by Wayne. They are not a scale model of anything Springfield ever made, but it is very unusual and interesting to watch. It is available in very limited quantities. Picture 6 is a preview of his next project. It is a 1/6 scale model of the Otto-Langen atmospheric engine. This model was produced by Grenning Models before in 1/7 scale, but the new version is more to scale, with correct pattern flywheel, pulley, and other mechanisms, as well as a more scale cylinder (the old cylinder pattern is shown). This model will be available in late summer. It will sell for $3500, complete with oak base, to hide the ignition system. Only 25 will be built, and very few are unspoken for.