Restoring an Oil City Boiler Works/South Penn cross-breed engine, Part 5

By Staff
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The fenced-in home of the Oil City Boiler Works/South Penn cross-breed engine, which was purchased and restored by the North Jersey Antique Engine and Machinery Club. Andrew Mackey and the rest of the club continued working on the engine throughout 2007, and finally got it running after a few false starts.
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Getting ready to start the engine at its new location. Andrew is checking the oil in the main bearing boxes. Note the 2-inch supply pipe for the cooling system from the top of the engine cylinder to the copper cooling tank.
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The copper cooling tank mounted in place.
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The propane accumulator is the hose at right. The fuel supply hoses at left go to the inlet valve.
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The air-fuel intake with the new valve and parts installed. Note the fuel delivery to the gas inlet. The 1-1/2-inch inlet air restrictor hadn’t been installed yet.

Editor’s note: The following is Part 5 of a six-part series about the purchase, retrieval and restoration of an Oil City Boiler Works/South Penn cross-breed engine purchased by the North Jersey Antique Engine and Machinery Club in 2006. Part 4 can be read here.

Awhile back, a couple of North Jersey Antique Engine and Machinery Club members went to the Coolspring Power Museum summer show in Coolspring, Pa., and saw an identical engine to ours on display. The owners were generous with their information about the engine, and even removed their intake valve assembly and took it apart so our guys could measure all the dimensions. They even had a scale to weigh the intake valve itself!

Armed with all the information, club president Blace Flatt took the valve seat to a machinist friend to have the work done.

When we got it back, it looked great, but Blace had reservations as to how well it would work. It turned out that the machinist thought the intake valve was too heavy (1-1/2 pounds), and took it upon his own to make the valve lighter than specified – half a pound lighter!

There is a spring at the base of the valve stem, but its only purpose is to keep the valve from chattering. It is not meant to actually close the valve; that is supposed to be done by gravity. We figured we’d see how well it worked once we got the engine fired up. Larry O’Neill assembled the intake assembly for us and we were ready for the next part of the job.

Installing the valve assembly
I took the newly repaired valve assembly, cut a new gasket for it and then installed the assembly onto the engine cylinder. The transfer port cover was permanently installed using the old gasket, which was still serviceable, and all the new nuts were installed on the eight existing studs. Luckily I was able to find 1/2-inch by 12 threads per inch (TPI) nuts at my friend’s hardware store, and all the studs had compatible threading with the new nuts.

After this was done, the oiler was also installed and filled with oil. I should note here that I filled the oiler to the top, which I later realized was an error.

Steven Boutellette helped me install the engine mounting nuts and we found that the 8-inch bolts were too long. As they were not of the old thread type, they ran short about 3/4 inch with the threading. I looked in my box of salvaged parts and found six 1-inch extra-heavy nuts to slip over the 3/4-inch shaft of the mounting bolts. When a flat and a lock washer were added, the new 3/4-inch nuts fit on the bolts perfectly.

The next four hours were spent building the accumulator for the inlet gas side of the intake.

I made the device out of a 42-inch section of type K copper pipe and two extra heavy pressure end caps.

The caps were first marked for center, and a 7/8-inch hole saw was used to make an opening. A 3/4-inch bronze pump flange was then silver soldered to the cap, centered on the hole. The end caps were then silver soldered to the heavy walled tube and the assembly was set aside to cool. Work was then started on the cooling system.

The cooling system
A week earlier, Blace asked me how we were going to cool the engine. I told him that we needed a good sized reservoir as the engine cooled by thermosyphon. He mentioned he had a 30-gallon tank that might work for us under his porch. I thought it might be too small, but figured we’d give it a try. He brought in the tank and in the process of bringing it into the building it was scratched, revealing that this was a copper tank! It had such a heavy patina that it was almost black in color!

The tank was then given a bath in muriatic acid, until all the patina was removed. The acid was then neutralized, and the tank dried and polished. It cleaned up well and only had one large dent in the shell where a 1-inch pipe connection was soldered in.

The tank had three 1-inch connections in the sides, a 1-inch plugged connection at one end and two 3/4-inch connections at slight angles from each other at the opposite end of the tank. It was decided to leave the two angled fittings at the top of the tank to act as vents for excess water and possible steam.

I used a 1-3/4- inch hole saw to drill the pilot hole through the brass plug in the bottom of the tank. The hole saw just skimmed the brass bushing that was soldered to the tank shell, and when it drilled through, the entire brass assembly came out. A 1-1/2-inch copper sweat female adapter was then soldered into the hole, with a heavy solder cap made around the entire fitting. A street ell was then threaded into the adapter and a 5-inch-long nipple was then threaded into the ell.

After all the fittings were made up tight, the nipple was cut 2 inches short so as to remove the exposed threaded section. A 4-foot section of 1-inch iron pipe was inserted into the nipple, and the street ell was turned until the nipple was oriented with the single 1-inch tapping on the tank shell.

I had picked up the piping for the cooling system earlier in the week. At first we wanted to make the system entirely out of copper but the price of copper nowadays made that unrealistic. I originally ordered the material in copper at a local supply house. When it came time to pull the material on the list the owner asked, “Are you sure you want to do this in copper? It will cost a fortune!”

I then asked what a 20-foot length of 2-inch type l copper would cost, and he replied “$269.”

“In black?” I asked.

“$89 for 21 feet,” was the reply.

“Sold!” I said. “Give it to me all in black.” Total savings: over $400 for everything!

Installing the cooling system
First, I had to remove a 2- by 1-1/4-inch bushing that was in the engine cooling inlet at the bottom of the cylinder. This was no easy task as we now had to work between the engine base and the new mounting frame. I used a 3-foot cheater pipe on a 2-foot Ridgid pipe wrench to remove the bushing, and in its place, installed a 2- by 1-1/2-inch bushing.

Next, I installed a short nipple, a 1-1/2-inch full tee, with a 6-inch- long nipple looking to the gas flywheel side of the engine, and another close nipple with a 1-1/2-by 3/4-inch reducer on the run of the tee, looking down.

Rich Magera helped me install and align the pipe work for the cooling tank. A 3/4-inch boiler drain valve was installed here so the system and the engine could be drained down for the winter. A 90-degree ell was then installed on the 6-inch nipple and it was turned toward the rear of the engine.

I then installed a 1-1/2-inch- diameter, 10-foot-long pipe into the ell with the open end sticking out the rear of the engine mounting frame between the engine bed and the top of the mounting frame. I cut a piece of 3-inch channel iron to fit on top of the frame and set it in place, flat side up. This raised the end of the pipe about 3 inches above level, which made it perfect for the thermosyphon application. The new channel iron section was then drilled and bolted to the mounting frame, and the pipe was set parallel to the wood beams mounted on the frame.

At this time, a 1-3/4-inch heavy duty automotive muffler clamp was installed by drilling through the channel iron and the clamp secured the pipe to the iron. The pipe was then cut off at a point 2 inches past the end of the channel iron and the end was beveled with a file. This completed the installation of the cooling system supply line.

Putting in the return line was a bit more of a pain in the butt as there was a problem trying to support it while taking measurements.

The first item was the vertical riser off the top of the cylinder. A section of 2-inch-diameter pipe, 30 inches long, was threaded on both ends and installed into the tapping on top of the engine cylinder. A standard 2-inch, 90-degree ell was then installed along with a 6-inch-long nipple with another 90-degree ell on that. The entire assembly was constructed with the final 90-degree ell facing the rear of the engine. Then came the fun part.

The final ell, mounted on the cylinder was hard to reach due to its height above the ground. As the long pipe to be installed into it had to run over the top of the engine, installing this pipe was difficult. Rich and I tried about four times to catch the threads properly without cross threading them and on the fifth try we finally got it caught.

Even though I had set the final 90-degree ell at right angles to the engine, the 11-foot-long section of pipe ended up passing over the rear of the engine to the left of center! It turns out that the tapping on the ell was threaded off square within the fitting, making the fitting actually more like 92 degrees instead of the standard 90. For all intents and purposes, this anomaly would not present a problem if a short pipe was used. But an 11-foot-long pipe compounds the error at the far end.

We ended up removing the long pipe and I again had to use the cheater bar on the 2-foot pipe wrench in order to give the riser assembly a nearly complete turn tighter so as to straighten out the long pipe direction. This time it only took two tries to get the long pipe started in the ell.

We then put a level on the pipe, and raised it so that there was a 1/4-inch bubble of pitch, 1 inch over 4 feet, with the incline raising toward the rear of the engine and what was to be the cooling tank location. The distance between the two pipes was measured at that point and I went into our building to complete the work on the cooling tank.

Using a square and a level, I determined where the tank needed to have the 2-inch female adapter installed, and then proceeded to use a 2-1/2-inch hole saw to drill through the side of the tank. This was done fairly quickly and a 2-inch copper sweat female adaptor was soldered in with a large bead of solder used for support.  

At this time a 6-inch-long nipple was installed into the fitting and the exposed threaded end was cut off. This end was now filed to smooth out the end of the nipple.

Using a string and the square, the distance between the ends of the 1-1/2-inch diameter nipple in the base of the tank and the 2-inch one in the side was determined. This measurement was transferred to the 2-inch pipe mounted on the engine. The long return pipe was cut off at that location and the end filed as on the others.

The tank was installed on the engine, with the help of Dick and Rich using two no-hub couplings. For those of you not familiar with plumbing fittings, a no-hub coupling consists of a neoprene sleeve with a stainless steel cover around the exterior circumference.

The entire coupling is secured by means of two radiator hose-type bands held in position by rivets through the stainless steel cover. It took about 10 minutes to get the tank set as some minor adjustments had to be made in the feed angle of the upper 2-inch pipe in order to get the tank level. With the copper tank now in place, a pair of brackets were constructed to support and steady it. These were made from 1-1/4-inch Unistrut framing, cut to 3-foot lengths and anchored to the 3-inch channel iron at the base of the tank with Unistrut right angle brackets, and three 8-16 bolt and nut sets.

Short pieces of tire tube were then placed between the galvanized strut and the copper tank to help isolate the copper tank from the zinc and steel supports, and to prevent a galvanic (battery) action between the two metals. The rubber would also dampen vibrations made by the engine as well. Three large stainless steel bands were then placed around the tank and the brace, and were then tightened to hold the tank in position. The cooling system was finally complete.

Thermosyphon cooling explained
This is how the thermosyphon cooling system works:

As the engine runs, it develops heat. The water in the water jacket around the engine cylinder absorbs this heat and the hot water rises. The hot water seeks the highest point in the system so it travels up the riser in the 2-inch return piping at the top of the cylinder. The hot water then continues up the grade in the 2-inch pipe, until it reaches and enters the copper reservoir tank where it begins to cool and sinks to the bottom of the reservoir.

In the meantime, as the hot water is rising and leaving the cylinder, cool water from the reservoir is entering the base of the engine water jacket, through the 1-1/2-inch supply pipe, filling the area vacated by the hot water. This cool water is now heated and rises as it warms, continuing the cycle. This circulation is called thermosyphon cooling. In practice, we have run the engine for more than two hours straight and the water temperature in the cooling tank has not reached 180 degrees Fahrenheit.

Supply piping installed
The last item to tackle was the setting of the propane controls and supply piping.

My son, John, and I went to a local hardware store and bought a propane regulator and hose to attach to the accumulator. I donated a gas grill regulator and long hose for the fuel supply to the hot tube burner. We also picked up all the piping and supplies from PJ’s Supply in Dover, N.J., for all the connection hard piping.

The first thing to do was to mount the accumulator. This was done using two 3-inch copper clad riser clamps and several studs set into the wood engine support beam. The supply regulator was set at 11 inches of water column pressure and was connected to the accumulator at the rear connection point. PJ’s Supply did not have a 3/4-inch flexible supply pipe to hook the accumulator to the intake valve on the engine, so I decided to make twin runs with two 1/2-inch flex lines and wrote up a parts list accordingly for Pete at PJ’s to pick out. Pete didn’t have all the items listed, so we made some adaptations in order to complete the job.

By the time we were done, $49 had the connecting parts in hand, including the two flex lines, for almost half the $89 price a single hose would have cost!

Now that the supply piping was done, the engine side was begun.

Engine side piping
A short 3/4-inch nipple was threaded into the outlet side of the accumulator tank. Then a 3/4-inch bronze body gas valve was mounted to the nipple with the control side facing up. A 3/4-inch, 90-degree street ell was then threaded and tightened into the front of the gas valve looking toward the ground. A full 3/4-inch tee was threaded on the bull onto a shoulder nipple and attached to the ell. Two more 3/4-inch shoulder nipples were then installed into the tee, and then a pair of 90-degree street ells were installed onto the nipples. Finally, a 3/4-inch pipe by 1/2- by 1/2-inch flex flare fitting adapter was installed onto each ell, and then the flex lines themselves were installed onto the adapters. This same set-up was used on the receiving end of the intake valve with one exception: the inlet valve needed a 1- by 3/4-inch bushing to be installed into the intake valve gas inlet.

As we were cleaning up from the night’s work, I noted another job that needed to be done before the engine was ready to be run: the new mounting frame needed to be bolted down to the concrete pad.

A few days later, the holes were drilled into the concrete base in short order, the bolts banged home and tightened up. After the water tank was filled, we were ready to try starting the engine!

Starting the engine
When I asked about the propane, apparently there was some miscommunication as there was only one 20-pound tank for us to use. I figured we had a methyl acetylene propadien (MAPP) gas torch so why not use that on the hot tube and the propane on the engine supply? Well, that’s what we did.

The propane bottle was connected to the accumulator supply hose and regulator, and the hot-tube torch was removed from its holder. The MAPP gas torch was lit and the tip put in the aperture on the hot tube chimney. SAE 50 oil was put in all the oiling points and the oiler petcock was opened. Some oil was also placed on the ways on the crosshead and on the piston rod as well.

The engine intake valve was held open until you could see the distortion in the air from the propane gas and then it was released. The decompression valve was opened and the engine rolled over until the piston had been drawn twice through a complete cycle in order to charge the cylinder with propane gas. At this point, I checked the hot tube to see if there was enough heat and there was plenty!

By now, several guys from the club had gathered outside the engine cage and were ready to see it run. I put them to work, turning the engine over. On the first compression stroke, the engine fired strongly but did not carry over to the next stroke.

The engine was then rolled to bottom dead center (BDC), the compression release closed and the engine rocked again. This time there was nothing, not even a sputter. The decompression valve was then opened, and after half a revolution, there was a great whoosh as the fuel/air mix in the combustion chamber fired! As the decompression valve was open, there was little movement on the crank.

The engine was again brought to BDC, the decompressor closed and the engine rocked against compression. This time there was a ground-shaking thump as the flywheel rims were pulled out of the starters’ hands! The engine carried over the compression stroke, fired again weakly, carried over the next compression stroke, and then rocked to a stop. So close!

With renewed effort, the crankers rolled the engine through several more revolutions but there was no effort on the engine’s part to start. As near as we can figure, the government-mandated fuel cut-off valve for the propane tank was severely restricting gas flow and was shutting down the tank immediately after the engine fired a few times.

Carl Sylvester, a fellow club member, had been watching the start attempt with interest. The club roasts fresh peanuts in an antique peanut roaster that Carl has restored. He said, “Why don’t you guys try the large propane tank we use for the peanuts? We just finished a batch, and we can switch tanks!”

The changeover was made in a jiffy, the MAPP gas torch re-lit, and again after several minutes, we were ready to try a start up.

After more false starts, a few unexpected exhaust reports and some exhausting cranking, we gave it one more shot. The engine fired on the first compression stroke and carried over for two turns but rocked toward a stop. I quickly opened the decompression valve, and the engine fired out the open pipe with a loud bang. The engine crank continued to turn, though, and I quickly shut the valve. As the crankers were reaching for the flywheels, the engine rocked slightly against compression and fired again. The engine reversed direction, fired again, then fired early, stopping and reversing the crank a third time, nearly at top dead center.

There was another ground-shaking thump and the engine flywheels accelerated. The engine carried over compression, we felt more than heard another thump and then there was a loud report from the exhaust. The flywheels kept turning, and the thump repeated, and another report followed. More booms and more whoosh sounds and it was finally running on its own! We decided Joe Cook was going to have to find another lawn ornament!

A cheer and applause rang from the crowd, as the engine ran for the first time in many years! We let it run for about 10 minutes, and then shut it down as I wanted to make a mechanical check of the entire engine.

Contact Andrew Mackey at 26 Mott Pl., Rockaway, NJ 07866 • (973) 627-2392 •

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