To recap an earlier article in GEM by Bob Hartwig in the September/October 1969 issue: Mr. Hartwig packed the wife, two kids and some tools into a Rambler wagon and headed out to Prescott, Arizona, to visit with relatives over the summer. His uncle Fred was a prospector and mining engineer who had a hot-head oil engine, a Venn-Severin Type E, in storage after its retirement from pumping water out of a local gold mine. Uncle Fred named this engine “Annie.”
I was on the mailing list for the auctioneer that handled Mr. Hartwig’s estate sale. About every square foot of clear land at the estate sale was filled with engines and equipment. I went to the sale with the Venn-Severin and a couple of stationary steam engines in mind. But at that time I didn’t know her name was Annie. It took a long time to get around to the Venn-Severin. I just kept coming back for another look; I guess there was a bond being made. In the end, I managed to purchase the engine for less than I had planned to pay. I had never seen one of these engines before, so when I got home I did a Google search for Venn-Severin hot-head oil engines. To my surprise there was only one hit: the engine I bought at Mr. Hartwig’s sale.
Annie at last
The first thing I needed to do was build a skid out of steel, big enough for the engine and cooling system to be lifted by a forklift. The cooling tank that came with Annie is old-style riveted and wasn’t tall enough to sit on the skid for proper cooling, so I had to make a riser for it to sit on.
Next, I needed to know what it would take to make it run. No matter how much oil I put in the cylinder, I couldn’t get enough compression for it to bounce back when rolling the flywheels. With the exhaust manifold off, the rings didn’t look right in the port; too dark and not making contact. Also, there was a check ball missing in the fuel pump; it couldn’t make pressure. That must have been why Mr. Hartwig had to belt start Annie, according to one of the relatives at the sale. Even though Annie didn’t run, in 2011 I took her to Caro, Michigan, then Portland, Indiana, more or less on a fact-finding mission. At the 2011 Tri-State Gas Engine and Tractor Show, I talked with the guys that run the Muncie oil engines. They told me about the value of water injection. These engines produce a lot of carbon, which can build up and seize the piston while running. Inject a little water and the carbon will break up and go out the exhaust.
I came to the conclusion that I needed to pull the cylinder apart. The cylinder diameter was 6.085-inch with 0.020-inch out of round and showing signs of scorching on the piston. This is an odd size bore; it must have been a manufacturer’s custom size. I took one of the rings off the piston and put it in the cylinder. Down about 3 inches, the gap between the ring and the cylinder wall looked like the Grand Canyon. That explained the lack of compression. I checked around and decided to have the cylinder bored and honed to 6.125 inches at a local automotive machine shop where they do the big stuff. The piston was spray-welded at Central Metalizing in Saginaw, Michigan, to size. I used my circa 1910 South Bend 9-by-36-inch lathe, with silver soldered carbide tips on blanks. I made two passes on the piston cutting 0.010-inch each time, resharpening and letting the piston cool down between cuts. If not, the tooling would spark out and the tip would be gone. Then I squared up all the ring grooves to the same size. I had Niagara Piston Ring Co. make me a set of rings, two rings per grove and four groves 0.700-inch wide. They’re pinned so the rings won’t rotate the ends into the ports and break.
I fitted the piston with 0.008-inch clearance, with the top ring end-gap at 0.040-inch and the rest at 0.030-inch. The rings were of the step-type overlap, which I had to modify to fit around the pins in the grooves. This was very time-consuming.
With the cylinder on my bench, I slipped the piston in the top of the cylinder, with the short side of the deflector on the head of the piston toward the intake port, and put an aluminum bar through the wrist pin hole resting on the cylinder. I installed all the rings, and found out there was too much material to compress with my ring compressor; almost 3 inches of rings. So I used a hose clamp, pulled the pin and pushed the piston down until the bottom rings were in the cylinder. I did this three more times to get the piston in. I had to use a block of wood and a hammer to get the top set of rings in; I continued to push the piston to the bottom of the cylinder to uncover the wrist pin hole. I then hung the 175-pound cylinder assembly over the engine crankcase and connected the rod and piston, then turned the crank throw to lower the cylinder assembly onto the crankcase and bolted them together. Before the head was installed I applied lots of oil to the assembly and some extra on top of the piston. After I finished up the rest of the little stuff, I was ready to mount the engine onto my trailer and install my pony starter, an 8 HP Wisconsin (Unit No. 466, Petroleum Machine Co., Seminole, Oklahoma) used for starting oil field engines. Next stop: The engine show in Caro, Michigan, where I could get some help with starting.
At the show in Caro I filled my water tank, parked my rig, blocked the trailer, and got registered. Rob Hall, my pony starter man, and I lit the torch to heat the head, we had a red glow. We started the pony starter. With the compression release valve open we engaged the friction drive into the flywheel as I turned the wheel. We have role over. We closed the compression valve and prime the fuel pump: nothing. Pump some more: more nothing. With a lot of vigorous pumping we got a little smoke. I thought we must have a fuel problem. I wasn’t sure if it was a pump or injector problem. I pulled the fuel line and operated the pump. Pressure was iffy, so I pulled the injector and reattached to the fuel line and pumped again: no fuel. I disassembled the injector and replaced the spring with a softer one and tested it again; there was fuel slobbering out. We put it all back together, better than before, but I wasn’t happy.
We went through the start up procedure again and got smoke only when I primed. We needed more fuel, so I lengthened the stroke on the fuel pump. The check ball wasn’t seating on the outlet side of the fuel pump; it couldn’t make pressure. The rings weren’t seated; there was too much drag on the piston and not enough compression to run. Crank the lubricator, more oil to the cylinder. I don’t think we were turning the engine fast enough to overcome all the shortfalls. All day long, all we accomplished was a lot of smoke and frustration. Dave Babcock came by that evening and offered to belt up his tractor to Annie. “I’m game.” I told him.
The next morning, Dave came around with his John Deere 50 and we belted Annie up and lit the fire. When the bulb turned red we started to roll the flywheels, closed the compression valve and released the fuel pump primer lever. It started to smoke. Dave said, “she’s running!” and asked if I wanted to flip the belt off. Before the belt hit the ground, I knew there was something wrong. Annie started to gain speed fast. I engaged the fuel pump lock out. The speed was still climbing, close to out of control. The blocks were no longer under the trailer. The trailer was bouncing 8 inches in the air. The trailer only stayed in place because it was connected to my van. We had a runaway! We quickly grabbed my CO2 fire extinguisher, pressed it against the air inlet reed valve in the crankcase and pulled the trigger. The engine stopped firing and I opened the compression valve; it fired 2 more times and coasted to a stop. It took about 10 seconds to get the engine stopped from when we removed the belt.
We had about three dozen people standing around when we started; half of them were gone and the other half had not a clue of what happened. People asked me, “Did that scare you?” No, but it had all my attention. Did I expect a runaway? No. This procedure of using a CO2 extinguisher on a 2-cycle engine has been discussed on Smokstak several times in the past. I thought I would never have to use it, but I’m glad I came prepared. Twenty-twenty hindsight: I had adjusted the fuel pump stroke way too much and when I locked out the fuel pump that also injected a full stroke of fuel into the cylinder. Also, there was a cup of oil and fuel in the crankcase left over from the day before. That extra oil and fuel in the crankcase, in a 2-cycle engine, can become an uncontrolled fuel supply for the engine. Annie likes to run at 150-250 RPM; that’s about 0.030-inch of pump stroke. Full stroke is around 1/2-inch. It was operator error, but we were getting better.
After we made all of our adjustments and re-blocked the trailer, we belted up and started again. This time we left the belt on. Dave used the pulley brake on his tractor to control the speed of Annie, applying a load and then letting her power up and down for about an hour. We also found out that after Annie started we could turn the fire off on the hot-bulb. We started the pony and cranked Annie right up. We forgot to light the fire, but had enough heat for ignition. This time I learned how to feather the priming lever to control engine speed, and how to adjust the positive stop on the fuel pump while the engine was running. It ran for another hour and then ran out of fuel. It was a real bummer to get running again. Then it was time to pack up, go home and get ready for Portland.
Monday afternoon we pulled into the line for camper registration. While waiting, I went back and told Dale Thompson to take a good look around: “You can’t see it all from here.” Dale is a first-year engine exhibitor and it was his first time at the Portland show.
Thursday was a good day to give Annie a chance to run. She was still hard to get started with the pony starter and got a little wild, but she didn’t run away. This time we went for the run, lost the blocks and the trailer started to roll away. We had to keep it at 150 RPM or less to keep it on the blocks. (I decided my trailer needed some down riggers when I got back home.) We had a lot of lookers stop by, even the Muncie guys. We had been working on the governor adjustments, but without any success. The “batwing-type” governor and eccentric that operates the lever and roller for the fuel pump plunger is all one piece with an offset pivot. It has a positive stop for the retracted position and another for the advanced position; both are adjustable. Also, there’s an adjustable spring to resist movement. These three things have to be adjusted with the engine stopped; otherwise it messes up the fuel pump stroke.
I had my down riggers ready for the show in Clio, Michigan, in September, the last show of the year. Annie was on her best behavior, blowing lots of smoke rings and posing for pictures. My trailer was stable at 250-300 RPM, but we still have to work on her table manors: she slobbers and drools. It’s what’s known as wet exhaust. I’m not sure if it’s unburned fuel or lube oil, but my trailer, and Annie, are covered with little slimy black dots. I need to get a cleaner burn. I’m thinking this might be a timing thing. I’m still working on it, with no luck. I have used Diesel and Kerosene, with no change. Maybe soy oil? There was a suggestion of McDonald’s French fry oil. Would that bring Seagull droppings?
I found out there’s another Venn-Severin like mine living in the Chicago area. I’ve thankfully been corresponding with the owner, Frank Chellino Jr., back and forth since early spring. I believe his engine runs smoother than mine, maybe mine will run smoothly after it’s broken in.
I need to thank my helpers, Rob and Dale, and Dave Babcock for his help belting Annie and for informing me about Mr. Hartwig’s GEM article about her.
Contact Bob Whitney at firstname.lastname@example.org.