Fuel Pumping System and Oiler Repair

Part two in a three-part series: Restoring a 4?HP Charter-Mietz oil engine


The four new post oilers and glass cover.

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I took a look at the camshaft arrangement for the pumps. There are two ratchet assemblies, one mounted on the fuel tank. This ratchet has a camshaft mounted on top that stops in four positions. The second ratchet is mounted on the rear end of the transfer port cover. It is spring-loaded, with a wedge-shaped tooth that engages a spider wheel on the camshaft. It ensures that the camshaft reel turns only in one direction. The camshaft reel itself has three sets of camshafts: two having four lug-type camshafts set 90 degrees apart, and each camshaft set itself was 45 degrees from its neighbor. The third set is the spider wheel, which has eight angular lugs that engaged both timing ratchets at various times. As the crankshaft turns, the ratchet assembly, when engaged, advances the camshaft assembly at the rate set by the adjustable ratchet. This can be from no movement of the camshaft, 1/8 turn, 1/4 turn and to approximately 1/3 turn. Each setting provides a different camshaft action on the pumps.

"I was astounded to find the bugger (the flywheel) weighed 351 pounds with the governor attached!"

On the first setting, with no movement, the setting maintains a simple stroke of the camshaft, maintaining the pump selected, whether it be on the primary or secondary pump. On the 1/8 turn setting, the camshaft is allowed to trigger both pumps on an alternating basis. For each revolution of the crankshaft, one pump or the other is triggered. I should note here that the secondary pump has the provision to alter the stroke of the pump itself by means of a threaded camshaft pushpin and jamb nut - for adjustment of stroke as required by the use of different fuels.

For the third setting, the position allows the camshaft to advance 1/4 turn, activating the pump selected at every revolution of the crankshaft. I believe this position is a set up position for the fourth setting. This last setting is triggered on the primary pump injection stroke only. The 1/3 turn allows the primary injector pump to be triggered only every other revolution of the crank. The engine double-strokes during this setting. If the engine were to be run constantly, and have long periods of no load, speed could be maintained during the no-load cycle with this setting at the savings of half the fuel normally used.

The entire camshaft assembly is mounted on a rocker arm, activated off an eccentric camshaft on the governor side flywheel. With the governor at rest, this eccentric has maximum throw, about 1-inch total, which translates to about 2-1/2 inches of throw at the fuel end of the camshaft assembly. As the engine speed increases, the eccentric is spun in its axis and at full-governed speed, the eccentric barely moves the rocker arm. The ratchet assemblies turn the camshaft assembly no matter what the rocker stroke may be, but the length of stroke the camshafts give to the fuel pumps may vary from nearly 1-1/2 inches down to no movement of the pump drive pistons at all.

The rocker also has a pivot pin opposite the camshaft assembly that drives the oiler. As engine speed increases, the pump stroke is shortened, maintaining a constant flow of oil to the piston and its bearings, but cutting back on volume as the load lightens. Luckily, the fuel camshaft assembly and both ratchet assemblies were not stuck. The governor was free as well, and only needed a cleaning and oiling. I did have to remove the governor side flywheel though, so I could place some needed thrust washers on several shafts to take out end thrust that was excessive.

When the engine was built, these shafts had virtually no clearances with the governor's rotating assembly and the linkages must have been a pain to maintain. I weighed the flywheel while it was off the crank, as it seemed to be unusually heavy for its size. I was astounded to find the bugger weighed 351 pounds with the governor attached! Guessing that the governor itself weighs around 25 or 26 pounds that still leaves 325 for the wheel itself. I cleaned out and repacked the well for the governor camshaft with cotton clothes drier lint, as the original material had rotted away long ago. I was getting tired and it was after 10 p.m. so I called it quits for the night - outside that is.

Though my first attempt to post questions at www.smokstak.com resulted in no information, I wrote once again about the Charter-Mietz and the Madison-Kipp oiler. This time I was more successful. Dusty Erickson from Arizona replied to my query and stated that the engine was related to the Mietz & Weiss Engine Co. of New York. As it turns out, Dusty has even written a book, Mietz & Weiss, New York, America's First Successful Oil Engine, based on his research and the company itself. I learned a lot of information about the operation of my engine as well as some things that did not seem to be in the norm in comparison with other Charter-Mietz engines known to exist.

Dusty also gave me the name of another Mietz & Weiss enthusiast, Fred Prichard, of New Hampshire. Fred noted several items as well on my engine that did not meet the norm, and after consulting others I came to the conclusion that my engine was unique in itself. No one had seen another Mietz & Weiss or Charter-Mietz set up quite like it. The general consensus was that either the engine was a factory prototype, not put into production, or that the engine was a college teaching engine, used as an educational tool. It would have been set up with changeable features and accessories in order to be able to run the engine with these changes and compare the results.

Fred also led me to another person who helped tremendously with the Madison-Kipp oiler. Dave Preuhs of Minnesota has a website dedicated to Hart-Parr tractors. Within the website, he also has a section devoted strictly to the Madison-Kipp lubricators. Hart-Parr used two versions of the Model 50 on their tractors and their internal parts were compatible with mine. Dave also rebuilds these lubricators and can obtain parts, although parts are getting scarce and more expensive because most of them are no longer being made. The lubricator section of Dave's site has a parts breakdown and an exploded view of each pump assembly (of which there are four in my unit).

The oiler

The outside of the oiler was only a little rusty, covered in oil and flaking gray paint, with a gloss black paint underneath. The case on the inside, the case interior and internal parts were not rusty either. The oiler case was half full of clean, clear water. This was due to the fact that the oiler drip rate sight glass had been broken a long time ago and the oiler case had filled with water. The ice formed when the oiler got cold, broke the sight glass and allowed any future water to seep out through the cracks in the glass. Three of the four oil lines were badly crimped and the fourth had been broken off at the fittings and was missing. Inside the case, all was not pristine either. After the original removal from the engine, I had sprayed the top of the unit with a load of WD-40. I again loaded the top with WD-40 and proceeded to clean all the crud off the case with a stiff bristle engine parts cleaning brush. When I was done removing all the built-up junk, I found the builder's plate in excellent condition! It reads:

Madison, Wis. U.S.A.
Model 50 Sight Feed
Pat. July 1, 1926 - Apr 10, 1918

The oiler identification plate is made of zinc, and the fact that it is even intact is somewhat of a miracle. The first hint of what I was to find inside was on the outside of the unit. The four zinc oil sight cups were all heavily damaged. There was not one that I could salvage; two of them were nearly totally eroded away. I tested the four oil rate adjusters and found two of them bound just as tight as the main shaft in the unit. This did not bode well. In the instructions from Dave's website, it clearly said, "Do NOT force the crank to turn, if the unit is stuck - severe damage could result!" The way this thing was stuck, I don't think my 2-foot pipe wrench could have turned that shaft!

I then removed all the screws from the top of the cover and tried to remove it. No such luck. I tried heating the adjusters, putting Liquid Wrench on them, hitting the cover with a plastic mallet and plain old prying. Just staring at it produced no results either. I finally got the top loose with a combination of efforts.

First I removed the crank handle and the pivot arm from both ends of the oiler. Then the shaft end bearings were removed, which provided some movement in the top itself, but not much. I hosed down the interior with WD-40 and some automatic transmission fluid from a squirt oil can and left the unit upside down for the next few days. I tried everything again and the top still would not budge. I was beginning to get a little steamed, so I took two big Craftsman flat blade screw drivers and hammered them between the top of the unit and the case. I could see where two of the adjusters were pulling on the top of the unit.

I tapped all of the adjusters with a small steel ball peen hammer and after the second round of spraying and hitting, the top popped off with a loud snap. The last two adjusters finally let go of the shafts on the oil injector pumps.

With the top off, I could see what I was getting into - it was not pretty. Each individual pump has a two-piece cam-eccentric mounted on the pump drive shaft. These in turn connect to a connecting rod with a small shaft mounted to one side.

This assembly is actually a dual piston assembly that works in the following manner: The cam-eccentric imparts two separate actions to each pump. The first action is a simple camshaft action. It raises and lowers the main pumping mechanism of the individual pump. The second action is that the camshaft design makes it wobble on the shaft center. This wobble imparts a twisting motion to the pump piston. The piston itself has cuts made in it and depending where these cuts align, the flow of oil can be regulated. That alignment is the function of the adjuster heads that are protruding through the top of the oiler. That is, they move the cylinder intake, which in turn regulates how much oil flows through the pump mechanism. The first motion brings oil up through the oiler sight tube. After the oil drips through the sight area, it is then forced into the engine by the second piston. In trying to turn the crank handle, I found that the number two pump cam-eccentric was the only item that was free, besides the shaft ratchet pivot.

I tried everything to free the shaft and the cam-eccentrics. As it turned out, the whole effort was an exercise in futility. Over the next three days, I tried everything to get the camshafts to move, with no luck. I tried heat (lots of it), WD-40, Kroil and Liquid Wrench, all to no avail. I finally decided that to effectively get the pumps out, I would have to remove them as an assembly.

I removed the oil supply fittings and the bolts that actually mount the pumps, and then tried to remove the whole works out the top of the oiler. The pumps came loose OK, but I still could not remove them. In fact, I now found that the camshafts were loose on the shaft, but were actually stuck in the connecting rod bores on three of the pumps. The problem now, was trying to get the shaft out of the pump case. It turned out what I thought was a single shaft through the unit was actually a two-piece shaft: one side driven by the engine governor pivoting shaft, relay rod, a ratchet wheel and pivot pawl assembly, and the other independently turned either by the ratchet wheel or by the external crank handle, mounted on the opposite side from the governor drive.

The two sections are linked through a brass keyed fitting, which is driven either by the engine link or the handle, and this in turn is held in place by a tapered steel pin. When the oiler stopped and seized, the pin was at right angles to the top of the oiler and I could not drive it out. As it was though, I could rotate the shafts about 1/8 turn due to the play in all the loose assemblies within the case. After three days of struggling, all I had to show for it was a bunch of cut fingers and a box full of loose parts and broken glass from the long gone sight-feed. To make matters more complicated and frustrating, the ratchet wheel pawl would fall out of position and jam the entire assembly to one side. Usually when this happened, the pawl spring would fall out of its recess and end up in the bottom of the oiler case. Getting it freed was a real pain.

Finally, the pawl fell out and jammed the shafts so tight I was going to take a hammer to it. As I was looking at the case with a real glare, hammer in hand, I noticed that the tapered pin was in a position where I could get a small pair of channel lock pliers on the small end and on the outer surface of the ratchet wheel at the same time, giving me an opportunity to pop the pin loose and to remove the hand crank-driven shaft from the unit. This was done in nothing flat, and much to my surprise when the hand-crank shaft was pulled out, the entire interior mechanism fell to pieces. I finally had the oiler disassembled.

Almost. As I was looking at the pumps and the zinc castings, I found out why the cam-eccentrics did not come free from the connecting rods or each other. When immersed in the water, the zinc became a sacrificial metal. That is, it was destroyed instead of the iron parts under water. This galvanic action made the zinc swell and split, seizing it in the connecting rod bores. The pumps themselves had also seized, rendering them useless. I contacted Dave and he told me he could get replacement cam-eccentrics, but they were $40 to $60 per half and I needed eight halves! Dave rebuilds MK oilers for a modest price, but he said it sounded like a replacement was more warranted than a rebuild in my case, due to the damage. Dave recommended I try eBay, and after five different auctions I finally won a new oiler.

The fuel pumps

I went to work on the fuel pumps and their piping. Both Fred and Dusty told me that the left-hand pump was the original primary pump for the M&W as well as the Charter-Mietz engines. Although the pump piston was stuck, the pump seemed to be in fair condition. The first objective was to remove the check valves and the primary fuel injector piping from the pump. The check assemblies are marked suction and pressure. On both pumps, the SUC checks were mounted to the rear of the pump and the PRE checks were on the front. The check valves were also full of crud and the primary pump also had water in it, due to a broken off fuel line. The primary pump piston was a pain to remove as well.

First, the packing gland nut was loosened. The pump return spring was compressed and that made working on the pump even more difficult. There was no packing under the gland anyway. The pump was then removed from the engine and the body was placed in a vice. A small slide hammer soon had the pump piston out and it was cleaned on a bench-mounted power wire brush. The pump housing needed a thorough cleaning on the inside as well because it was full of sludge. I did not clean the exterior of the pump very much, as there were rust spots on the paint that was on it. The pump was reassembled with new packing and the pump was remounted on the pump mount plate. The secondary pump just needed a tap on the pump shaft to free it. It was missing the discharge check and all piping.

The fuel injector nozzle was cleaned, as well as the injector housing and a new supply pipe was made from a piece of 1/4-inch copper tubing. The supply line goes from the fuel valve to the pump inlet check. The valve on the tank had three connection openings available: one was marked gas (on the side, capped) and the other was marked kero (on the fuel tank side). The third connection was a compression fitting for connection at the inlet side. This consists of a ground-in ball and socket fitting that is soldered to the fuel line, and a lock nut that butts the ball end of the adapter into the socket in the check valve. The fuel tank supply line had been wrung off and I had to remove the old snapped piping and install a new one. I heated the soldered fitting, grasped what was left of the copper pipe and gently twisted. Once heated, it slipped out of the brass fitting easily. I noted the original solder joint was not well done and I needed to clean out the oil brass fitting.

I taped 100-grit emery paper to a 1/8-inch drill bit with a piece of duct tape. I then inserted it into the brass fitting and spun it with the drill for several seconds. I then inspected the brass and it was clean and shiny on the inside. I made a new copper fuel line, and after a trial fitting and several adjustments, soldered the line to the fitting and then made the compression fitting on the tank valve.

This done, I put kerosene in the fuel tank and worked the fuel pump lever quite a few times. I could hear the injector working after a few strokes of the primer lever. I also saw some kerosene leaking from the pump packing. I tightened the packing gland nut and quit for the night.

Since I'd bought parts from Ed Deis from Hit & Miss Engines in the past, I thought I'd give him another try. They had a two-post unit, free - not stuck, but in unknown internal condition. It cost $75. I received this oiler and the other I won off eBay on the same day. Both units were pretty grungy, covered in grease and grime. I hosed both of them down with Gunk Engine Brite engine cleaner and scrubbed them with the bristle brush I used on the original oiler from the engine. I then hosed them off with water and kerosene and proceeded to disassemble both units. They each took a day to take apart and luckily the internal parts in both were in good shape. I ordered several parts from David, including the glass hood for the four-post top, the replacement for the keyed spacer and a gasket for the pump mounting flanges.

Putting the oiler back together was a real chore. The pumps had to be reassembled, and the camshaft halves installed into their respective connecting rods. The adjuster rods also had to be placed in their bores and the entire pump assembly mounted on the hand crankshaft. This procedure must be repeated four times and as each pump is installed on the shaft, the camshaft assemblies must be aligned so the timing camshafts engage each other. The only problem is that each time you pick up the shaft to install the next pump set up, the others fall apart. After several attempts, I got smart and put rubber bands around everything that could move, and finally I was ready to put the assembly into the case.

The next issue was installing the engine drive shaft and the ratchet wheel assembly into the case, and hooking it into the pump drive shaft work assembly. As with the disassembly, the ratchet wheel pawl provided the most trouble. Trying to get the ratchet wheel, the pawl, its spring, the two shafts, all the pump timing keys and the tapered pin mount holes to align was nearly impossible to do by myself. I enlisted the help of my two sons, Richard and John.

At this time, I made one change to the internal working to the lubricator mechanism. I changed out the original ratchet wheel with one from one of the two units I had bought. The replacement wheel fit perfectly, the only difference being that it had more teeth on it than the one from the original oiler unit. This gives the oiler a better flow control rate than the old wheel could give. After about an hour of trying to align everything, we finally succeeded in installing the pin, completing this section of the repair. It remained to mount the pump bases to the case with the gasket, install the top, sight glass and other various items.

Oiler assembly

I installed the needed spacer and the shaft end supports. The engine drive side end support was severely worn. The bronze bushing the shaft rides on was nearly cut through with wear. I reasoned that this was one of the causes that there was so much damage to the zinc parts inside the oiler. Besides the galvanic action between parts, there was also physical wear, due to the fact that the bushings were worn out so badly. In fact, while I was looking the packing nut over, I noticed it looked like it had been hammered on and the threads were stripped out on the gland nut.

I decided to replace it with one of the units I had bought. As it turned out, only one of the four packing glands used was like mine on the governor drive side because it had an adjustment on the inside to take out thrust on the internal works. The other three were fixed bushings, with an external packing gland only. I replaced both supports with those from the H&M oiler, as they were hardly worn.

The next step was to mount the oil pumps within the case. The pumps are secured with a 5/16-inch fine thread bolt and the oil supply fitting at the base of the pump that has a lock nut on the 1/8-inch pipe threads. Each pump must be aligned horizontally and vertically. This is necessary to align the pump drive eccentrics without binding. What made it even more complicated is that the gasket for the four pumps was a one-piece affair. I had to keep loosening the pumps already installed in order to install the next pump.

Finally, after all four pumps are mounted into the case, you have to snug up the bolts, then install the outflow adapters, tighten the bolts and then snug the adapter lock nuts, after you turn the adapter to match the oil line direction. Thankfully, all four of the oil lines face straight down as they leave the oiler. After everything was aligned, all connections were tightened. Once I had all the pumps locked in position, I installed the hand crank and attempted to turn the handle. It wouldn't budge. I then gave everything inside the case a liberal coating of SAE 30 oil, backed off the endplay adjuster inside the case a little bit and again attempted to turn the crank. This time it turned smoothly with the ratchet wheel pawl making a genteel click, click, click as it turned.

I locked the adjuster lock nut and went to work on the top for the original oiler. I had to wire brush the top in order to remove the old paint and some rust. I also had to free two of the four oil pump adjuster knobs, as they were frozen in place. This done, I installed the top temporarily and prepared to paint the oiler case.

Painting the oiler

I put some grease on the pump drive shafts, the oil pump sight feeds and the zinc receivers. I also put some grease on the zinc oiler identification plate and the hand crank to protect them from over spray. I then taped off the exterior of the case around the oil level sight gauge mount and painted the gauge area with Krylon Chrome Silver paint, as it was originally silver. I stuffed the oil level sight area with paper napkins and painted the entire oiler with two coats of Krylon glossy black paint. I removed all the grease with a rag soaked in kerosene.

Next, I assembled the oiler level gauge glass from the H&M oiler into the engine oiler because it was in better shape than the one from eBay. I bought new gaskets for the glass gauge from Lee Pedersen, as well as a roll of gasket material, as the gasket for the oiler sight feed glass was no longer available and I had to make one.

When the gauge glass was secure in its mount, the oiler top was ready to be installed. I salvaged new screws for the oiler top mounting from the other two oilers and I polished them on my bench polisher. I also polished the screws for the sight feed glass. I had to salvage these screws, as all but one of the originals were lost long ago when the glass was broken out. I had to salvage the glass retainers as well as the screws. Between the two oilers, there were just enough screws and retainers. (By the way, if anyone needs the sight feed glass for a two-feed Madison-Kipp oiler, I have two.)

I then mounted the oiler top onto the case. Mounting the top presented two problems: One was that the sight feeds and the catch cups have to be bent into position after the pumps are mounted. They must not hit the case top, as movement within the case and engine vibration will cause the zinc castings to fail. The other problem is also related to the first. That is, the oil feed adjusters are a slip fit into the adjustment caps that are mounted on the top. Trying to get all four aligned was a real task.

Once I got the top mounted, making a new gasket and mounting the sight feed glass seemed easy. All that remained to do now was to mount the oiler on the engine, make the oil supply piping to their delivery points, install the oiler pump drive arm and linkage to the governor drive arm, and make final oiler adjustments.

Remounting the MK oiler was the easiest part of the whole job. Putting on the two forged steel brackets was a matter of installing two bolts and two nuts. Getting the oiler drive arm adjusted was not so simple. The first thing I had to do was establish the center of throw of the drive camshaft on the engine. I removed the compression release valve and cleaned it - it is made of brass. Removing the valve altogether made it easier to roll the engine through the compression stroke. I rolled the engine through three or four revolutions and noted where the camshaft stopped and reversed direction at each end of its throw. I turned the engine so that the oiler drive pin on the camshaft drive was at mid-stroke. Then, I moved the MK oiler through a complete throw of the driven arm and also made a note of where the center of the oiler's stroke was.

With the oiler set at mid-stroke, I mounted the oiler drive arm relay rod on the camshaft drive pin and holding the MK driven shaft still, I tightened the drive arm in position with the relay rod attached. This positioning put both the oiler and the engine camshaft assembly at mid-stroke. When the engine was turned over, I heard the ratchet wheel click twice. I turned the engine to top center and turned it through a full revolution. Again I heard two clicks, as the engine was on the compression stroke. As the camshaft cycled, I noted it was not clicking for quite a while, as the rod was drawn toward the engine. I figured the ratchet wheel must have been near the trip point when the road stopped retreating and I was not getting the full amount of shaft rotation that was available. Adjusting the relay rod became a real time consumer, as the ratchet off points seemed to change with each turn of the crank.

Finally, I stopped for a break and glanced at the governor spring. Then it hit me! As the engine crank was turning, the play in the governor spring was allowing the governor to change the stroke of the camshaft as I worked. I did not have a constant point of reference to set up the oiler. I then re-set the governor spring to take out the play and then re-set the camshaft pin-oiler drive arm relation so as to get three clicks on the ratchet at every engine revolution. This gave the oiler one revolution of the oiler shaft to approximately 30 turns of the crankshaft. Later on, when the engine was running, it turned out to equal one revolution of the oiler to every 6 seconds with the engine at speed.

The MK oiler feeds four points on the engine from right to left on the oiler itself. The first position feeds the right side main bearing; the next, center right, feeds the piston and wrist pin through the transfer port cover. The third position, center left, feeds the left main bearing and the fourth, left side feeds the connecting rod through a slinger - gravity tube pick up on the left side bearing plate. The recommended oil is SAE-50 non-detergent oil. As of now, this oil is not available in my area, so I am using SAE-50 racing oil. I made up a new piston feed oil line, as the original was missing, and straightened the other three lines. I made up all the compression fittings and put new ferrules on the replaced line, thus reusing the old fittings.

I should note that most of the pipe fittings were standard National Pipe Thread (NPT) with the exception of the fuel system. Although I had asked Dusty if the threads were of a standard nature on the Mietz & Weiss engines (and he assured me they were standard, nothing special) I did find an anomaly on the Charter-Mietz: the threads per inch were the same, but the taper of the threading was about one-half of the NPT thread. The thread was a so much more shallow tapered that the fitting threads were about 1-inch long on the check valves instead of about 3/8-inch on a standard 1/4-inch NPT nipple.

When I was done with the oiler piping, I went to my local NAPA auto parts store and asked for their required SAE-50 oil. I bought two quarts at $3.29 per quart. This put the oil about two-thirds of the way up the oil level gauge, so I gave it a few turns. There was only a little resistance to turning and there was no oil flow. I then opened the oil adjusters all the way open and then again turned the hand crank. After about 20 turns, the oiler was primed and pumping oil into the bearings. Another milestone reached. I reset the oiler drip rate to one drip per revolution for each of the four posts and then figured I was ready to try and start the engine.

Tune in next issue for part three covering startup, the cooling system and the first shows.

Contact engine enthusiast Andrew Mackey at: 26 Mott Place, Rockaway, NJ 07866.