My 1910 Mitchell "parts car" project

[JV Puleo]

I thought of making a clamp but this bearing is very thick - the finished OD is just under 2" and the camshaft is 7/8" so there is no crush. It has to fit the hole perfectly and is then held in place with a set screw. I'm still debating how to make the main bearings and for those, I suspect the clamp idea is the way to do. My mains need one thrust surface on the front and back and two on the middle bearing so I'm thinking of a clamp in two pieces that the shells can be mounted in. When I get to that, I'll first align bore the crankcase so that all of the raw holes are identical. That way, the same clamp will work for all of them. It will probably be quite an operation. The original bearings are Babbit poured directly in the aluminum block with pins in the aluminum to keep it from turning. Now that I think of it, the caps are iron and the Babbit is very thick, more than 1/4". I suspect the original journals were hardly align bored at all and they relied on the thick Babbit to "straighten" the crank.

 

The method PM Heldt describes as being the most common is to make the two halves and solder them together after which the piece is machined as if it were solid. Then it can be heated and the halves separated. I don't have enough confidence in my ability to solder them perfectly and Heldt does say that there is a high failure rate in doing it that way when they fall apart before being finished. I may try it some time just to see if I can do it. Heldt also illustrates a set of fixtures used to make split bearings but to me, they look like far too much work to make a single bearing.

Edited April 15, 2019 by JV Puleo (see edit history)

[edinmass]

Pouring the Babbitt onto the case is problematic, and over the years I have seen a handful of failures. I have seen others make shells and they have worked out fine........also way beyond my abilities. Repairs such as these are not only challenging to figure out how to do it, support the work, etc......it’s the time EACH process takes to figure out as not to ruin anything, or make a mistake that doesn’t show until a bunch of processes further down the project. The thought process on repairs like these are often ten time the actual machine work time........again, also beyond my abilities. The trick to every pre war car, is to know your skill set and abilities, and have a bunch of friends who have other talents to help you out along the way........the most important thing is to do no harm and cause bigger problems. Hand operated custom machine shop work is a fast dwindling skill.......most of my go to guys over the last twenty five years are retired or will soon be........it’s getting harder every day to get projects done.

[JV Puleo]

I don't think there is any doubt about any of that. But, on a more optimistic note, there are people like myself who don't come from a background that encompasses these things but do it because we want to. That probably doesn't get the person who just wants to take his parts to the machine shop very far but it does mean that new people are coming along who at least know how to do things... we just don't see it yet. I know at least one who is 30 years younger than me but he's a software engineer by profession. One of the best things that have happened to me is the advent of CNC - which I personally have no use for but has made all sorts of functional and otherwise perfectly usable machine tools really cheap. I've hardly paid more than scrap metal value for most of my shop and some of the machines were give to me.

 

As usual, Ed's observations are spot on. It is difficult to explain to someone who doesn't do this sort of thing how much thought goes into making or fixing something before you ever touch a machine. I have notebooks full of scribble drawings of parts - that I discarded before ever starting on them. I suspect most people think it all comes from Amazon and they can get it delivered in 2 days.

 

I think pouring Babbit into an aluminum crankcase is a very poor idea. The pins were there because it doesn't stick - or doesn't stick well and having it as thick as it is on the Mitchell is just shoddy work but I don't expect the makers expected the cars to last more than 5 years which was about the life expectancy of a 1910 car. Very well made cars, Pierce-Arrow, Locomobile, Packard, etc. often lasted because they could be made into trucks. The cars that survived intact are anomalies.

[Bush Mechanic]

With regard to PM Heldt's description of soldering the halves together. If combined with a hose clamp it may assist in the machining of the surface on which the steady runs. But I think two clamps at that stage would give sufficient rigidity. My bearings are 3" long, plus support length, hanging in a small 4 jaw chuck. With the stock out of round after slitting, turning the steady track will be 'gently, gently'.

And we have finally seen full view photos of your lathe and mill. (Perhaps I missed them in an earlier post). Well preserved and robust older machines always look good to me. Excellent.

[Mike Macartney]

Thanks for sharing the photos of the crankcase repair work. I always thought my solutions to overcome problems were quite good, but your thoughts and work knocks my efforts into a cocked hat! I agree with Bush Mechanic, it is nice to see complete photos of your lathe and mill. As I have said before Joe - fantastic thought and workmanship.

[JV Puleo]

This is how the crankcase is mounted to work on it. Aluminum crankcases are VERY flexible. It was dut to an excellent post by Ivan Saxton on this site that I first realized how critical this was. There are 1/2" steel plates bolted to the upper face of the case using the original threaded holes with lock nuts on the inside. Then the entire case is bolted down to this old lathe bed made into a work stand. This is all critical when it comes time to bore the main bearing journals.

 

 

I also finished the cap. I don't think I spent half an hour on this - the obvious result of having done it before and having some practice. I think this is the best knurling job I've done so far, another example of the value of doing something enough times that you start to get the hang of it. On the far right is a crankcase breather I bought from McMaster Carr. When I got it and realized how simple it was, I decided I could make one that would look much more "in period" out of an old compression fitting. The thread on the bottom piece, originally intended for a flare fitting, is 1/4NPS so I'll need a tap.

 

[alsfarms]

What a resurrection!

Al

[JV Puleo]

I was at loose ends yesterday trying to think of what to do next so I decided to have a go at making a thumbscrew. I used a piece of 12L14 - free machining steel. I drilled and reamed it 1/4" and then counterbored it 5/16" (the diameter of the socket head cap screw end). I knurled it first... because I wanted all the thickness to withstand the strain. Then I cut it off with the lathe cutoff tool.

 

 

I looked pretty good, so I brazed the screw in place from the top and then faced it off so that all that shows of the brass is a tiny line around the head and the filled in hex.

 

 

And replaced the cap screw in the pressure relief valve. I realize this is a little overkill but I get a lot of satisfaction from little details like this.

 

 

Today I split the cam bearing, something else I've never done before. The first step was to measure the distance between the top of the bearing and the center of the hole to calculate how much to raise the table - hoping to get the slot exactly in the center. It's the distance between the top of the 3/4" shaft + .375 (half the thickness of the shaft) + half the thickness of the saw.

 

 

Then set it up in the mill and took a light cut.

 

 

It seemed ok... so I proceeded. Cutoff saws run at a very low speed - I think this was turning at 66RPM and I took very light cuts. The idea is to get as smooth a surface as possible on the inside of the cut. Here it is with the first side done.

 

 

And finished. All in all, I appear to have done the math correctly. I'm going to lap the inside surfaces then drill, countersink and tap the holes for the cap screws that hold it together - maybe tomorrow. Like that last step threading, this sort of thing is tension inducing and I'm worn out from it. I'll go on to something simple for the rest of the day.

 

 

[Luv2Wrench]

The saw just looks scary. ☠️

[JV Puleo]

More like boring. With the slow spindle speed and slow feed, it takes forever. I suspect I could have fed it faster and could have taken deeper cuts but having it come out good is a lot more important to me than doing it fast. If I do more of this sort of thing I'm sure it will get both easier and faster.

[Terry Harper]

Joe,

It looks great! Its obvious that this project is in good hands!

 

Terry

[JV Puleo]

Sometimes I'm not so sure. I did tell the owner of the car that I wasn't surprised several engine shops turned down the job. If I were in business, I might have also but the real problem was that very little of what I've been doing falls into the purview of what engine shops do. Chances are, there are few - or none - that have the equipment and some of the machines I've been using I got after I took the job.

 

Today I pressed on with the bearing - I'm starting to think it will come out all right and want to see it done. First I drilled out the holes in the upper side of the cap for the 10-24 cap screws.

 

 

Then counterbored the holes because they have to sit well below the surface. I need 3/8" between the bottom of the counterbore and the inside surface and, lucking the pilot on the counterbore is exactly that. I also set a stop on the drill press quill just to make sure.

 

 

It's amazing what you can do with this crummy old drill... but you have to be very careful and bolt everything down tight. I then tapped the holes in the other side of the bearing. Always a bit worrying because bronze doesn't tap all that easily and a broken tap here would be a disaster.

 

 

I also lapped the faces... this is my old way of doing it, a piece of 220 wet or dry on plate glass with a little light oil. This is lard oil - once the standard for fine cutting oil. (That is what Harry Pope used when he cut the rifling in his barrels)... fortunately, you can still get it. I finished up with the lapping plate but this way is faster and probably about 90% as accurate.

 

 

Everything lined up and it went together as well as could be hoped. It isn't actually perfect... the two halves are probably about .003 out of square with each other but I designed this to accommodate that and never expected it to be any better.

 

 

The next step is finishing the inside hole which isn't easy because neither the hole or the piece are round anymore. The next idea only came to me today while I was working on this. I measured the dimension across the hole at its smallest...it is .650 which is what it should be, mathematically, but things rarely come out so close. I took a piece of 1" bar - it is actually the original dummy camshaft I'd used in the oil pump, and turned it to .650. The idea is that if it fits smoothly and without any "shake" in the hole it will be straight and I can then indicate the 1" end to bore and ream the now oblong hole.

 

 

It seemed to come out fine. It slides in but there is no wobbling. If all goes well I'll put it in the 4-jaw chuck tomorrow, indicate the hole in the center and bore it.

 

 

Edited April 19, 2019 by JV Puleo (see edit history)

[1912Staver]

On ‎4‎/‎14‎/‎2019 at 3:27 PM, JV Puleo said:

I knew I had these somewhere.

 

Milling the top of the crankcase flat. It was critical to make a fixture that held it perfectly flat and to bolt the entire thing down to the table.

 

 

The crankcase set up in the lathe. I took off the saddle and used it as a horizontal boring mill. The boring bar is from my portable boring bar. The piece in the main bearing saddles was used to get the exact measurement.

 

 

 

You can get an idea of what I was dealing with here.

 

 

That's a lot of weld. Was the crankcase heat treated to help normalize any welding stress ?  Cryo treat before machining ? I would be afraid after a number of heat  / cooling cycles once the engine is run again things will move around and throw all your careful machining out of alignment.

 

Greg in Canada

[JV Puleo]

I have no idea. It was done years before I saw it.

 

 

[Mike Macartney]

Greg, sometimes in life you have to take a chance. The part was scrap and nothing else was available. Good on Joe for helping to get this old car engine back on road.

[JV Puleo]

In thinking about it, I wonder if the crankcase actually gets hot enough to make a difference? I don't imagine it gets hotter than hot oil and I've never been scalded by the oil when I drained a hot engine...maybe 140 to 150 degrees? This is only 40 to 50 degrees hotter than the ambient temperature on a hot day in New England.

 

This morning I bored and reamed the hole in the center. First I set it up in the 4-jaw chuck and indicated the guide piece I made yesterday.

 

 

Then bored it round again.

 

 

I took it out to a little less than 1/64 under the finished size - about .012 and reamed it with a 7/8 reamer.

 

 

This is it... it fits the camshaft perfectly.

 

 

Now I have to double check some measurements and turn the OK. That is the really tense operation because there is just about no wiggle room.

[JV Puleo]

I seem to be having a good day so I decided I might as well try the next step. I put the bearing on a mandrel and turned it down to the finished size... 1.925

 

 

It fit just about perfectly...

 

 

All that is left is to make the oil pockets and the oil groove.

Then, because I have to finish the intake manifold in order to get measurements to finish the oil manifold I soldered one of the elbows to a spare piece of tubing. This is to hold it while I file and sand.

 

 

I also started on the special bolts with built-in standoffs that will hold the manifold on...

 

 

This is also an experiment in making identical pieces, something that is a lot more demanding than most people think.

 

[JV Puleo]

I finished up the special intake bolts today. The next step was to turn the diameter that will be threaded. I then single pointed them about 85% of the way.

 

 

And then screwed them into a die.

 

 

This gives you nice uniform threads that are really straight. It's practically impossible to start a die on the end of a piece like this and really have it run straight. (Or at least it is for me) but cutting away most of the material first, in the lathe, ensures that the die will run straight.

 

 

Then I shortened the heads - the extra material was there to provide a better grip in the hex collet. I then set up the radius tool and put a slight crown on them.

 

 

All done.

 

[chistech]

Beautiful work Joe. Having done some like this myself in the past, I can really appreciate your work. The average person only gets as close as inserting or removing a bolt, never thinking twice about them. Making them, especially custom ones like these which actually are still kind of simple in design, gives a whole different appreciation for something lots of us use everyday.

[JV Puleo]

I see it as all in the way of practice/ At some point I have to make the high-dome bolts that hold the wheels together so I'm anxious to work out the details. By the time I get to that, I should have a "bolt making" process sorted out. I could have used hardware store bolts and standoffs from McMaster Carr but I think this looks much more as if it was always that way.

[JV Puleo]

My homemade crankcase breather. A 1/4NPT to 3/8 (1/2 OD) tubing compression fitting without the ferrule, two pieces of 100 mesh copper screen cut out with a gasket cutter and two 5/8" OD x 3/8" ID fiber washers.

 

 

Without the ferrule in place, these fit under the cap.

 

 

When I assembled it I noticed I had another cap with a little raised edge so I used that one.

 

 

I've no idea if this was ever done this way but all the components were available c. 1910, including the compression fitting.

Edited April 20, 2019 by JV Puleo (see edit history)

[alsfarms]

Your close-up view of one of you knurling jobs is great.  You make nice crisp knurls!  You musty have a nice sharp tool and use a suitable amount of side pressure to form the knurls a nice as you have!

Al

[JV Puleo]

Yes. I seem to be getting the hang of it. There is a little technique involved and it has taken me more than a few tries to get it right but the last two came out nearly perfect. We'll have to see if I can keep up that record.

[Mike Macartney]

Joe, have you any tips on knurling to help us learners? Does the lathe speed need to be as low as possible?

[JV Puleo]

I run the lathe at the lowest possible speed. It's critical that the piece being knurled be held very securely. I usually attach it to a fixture held in a chuck or directly in the chuck.

You then have to get both knurling wheels in contact with the piece and absolutely parallel. Then I start the knurl with a light cut and with about half of the wheel on the piece and run it down until it's about half off. Stop the lathe, reverse direction, turn it in a little more and run it down again until it's about half off. It's critical that the wheels never come off the piece since it is virtually impossible to put them back in exactly the same place. Usually, four passes, turning it in a little each time is enough but I stop the lathe and take a look and don't pull the knurling tool back until I like the result.

[JV Puleo]

I now have to assemble the intake manifold...something I've been putting off because I don't particularly care for the polishing I'll have to do. But, there was no putting it off now so I soldered the elbows to a short piece of tubing to hold while I filed and sanded them.

 

 

They took about 2-1/2 hours each to do and I have to admit they came out pretty good. I assembled the pieces on the engine to get they straight with each other. I then stuck the interface between the threaded elbow and the flange in two places to lock it in place.

 

 

Then I very carefully took it apart and soldered the elbows to the flanges. Ordinarily, I'd be a little worried about using plain lead solder here but the elbows are threaded into the flanges so all the solder is doing is holding them tight and filling whatever space there is between the male and female thread.

 

 

After cleaning the elbows up, I reassembled it again and soldered the tube in place.

 

 

I think it's ok... tomorrow I'll finish up the carburetor side.

They certainly don't look like the pipe fittings they started life as.

Edited April 22, 2019 by JV Puleo (see edit history)

[Terry Harper]

Joe that manifold looks most excellent!

 

You have inspired me to get mine finished as soon as I have a few nice days to work outside.

My plan is to mock-up the manifold using the cylinder blocks as the jig and solder it all up in place.

 

That way I can ensure it fits properly since the mounting studs are not exactly perfect.

 

The castings have been laying around on the work bench way too long!

 

 

 

 

[JV Puleo]

Do it... my parts were hanging around for months before I had to put it together. And, yes you must assemble it on the engine. I had the same problem - nothing is really square or uniform so the only way to make sure it fit was to assemble them on the blocks and solder them in place. I was not able to get around in the back well but I took it off and fixed those spots afterward. If you're careful, nothing will move.

[Mike Macartney]

Thanks for the tips on the knurling. I now know where I have being going wrong!

A super job on your inlet manifold. You should be very pleased with the outcome.

[Terry Harper]

Joe,

Are you going to acid pickle the manifold to neutralize the flux?

[JV Puleo]

I hadn't given that any thought. What would be appropriate? I rather dread having to repolish the etched surface. Wouldn't you use a strong base to neutralize the acid? (Keeping in mind that I know nearly nothing about chemistry.)

 

I cleaned up the other end of the manifold and assembled it this morning.

 

 

then calculated where the oil lines have to go. It's more complicated than I'd thought because they can't overlap neatly. I came up with a plan in any case but it will be a long time before I have to install them. First, I squared the oil manifold on the milling machine table. This is where the flats I put on the ends come in useful... it was no problem getting the holes perpendicular to the manifold.

 

 

After the holes were drilled, I tapped them 1/8NPT

 

 

Here's the finished piece. Before I can go forward with this I have to get all the burrs out of the inside. I may have to order a  flex-hone for that. I need it to be completely clean before I assemble it since oil will be running through it. This is brass pipe. The wall thickness is greater than most tubing but still not enough that I will feel comfortable just screwing the flare fitting into it so when everything is finally assembled I think I will solder them too. The entire unit has been designed so that it can be taken off the car without having to slide it through the aluminum collars that suspend it from the water lines. It took me quite a while to think of a way to do that.

 

 

I will probably go on to something else tomorrow while I wait for whatever I need to finish this. when it is done, I'll incorporate it into the test stand with the idea of testing the entire oiling system off the car.

[Terry Harper]

Hello Joe,

 

From what I understand pickling removes any scale, flux residue ect. The solution recommended for brass is 10% sulphuric acid. However, there are some

home grown solutions ranging from vinegar to lemon juice to alum. You will have a redish copper blush that can fairly easily be removed.

 

Anyway, since my assembles are a combination of brass and bronze I am not sure if I can use sulphuric acid or not. There is also a vinegar and hydrogen peroxide

pickle solution that supposedly removes the copper blush.... still studying this!

[JV Puleo]

Hmmm.... all my fittings are bronze. The tubing is copper but I don't think there is any brass there. I did, originally, make brass flanges but I didn't like the mismatched color and wasn't really happy with their form so I made a pattern and had the guys next door get me two bronze castings.

 

 

[JV Puleo]

While I'm waiting for the flex hone I decided to make the dust covers for the lifters. I made the lifters a long time ago. At the time, I couldn't think of a way to make dust covers for them. The ones I have seen were stamped from sheet brass but that's beyond me... not having a stamping press or knowing anything about making dies for one.

 

 

I cut 3 sections of tubing. 2" long. I had planned to ream them to size but that didn't work. I couldn't tighten the chuck enough to hold the piece firmly without distorting the tube which, in turn, caused the reamer to stick. In the end, I bored them about .020 larger so they would slip over the lifters.

 

 

When that was done, I cut them in half giving me 8 pieces about 1" long. I see now that I failed to photograph a couple of steps but I set a stop on the lathe and cut the rings down to 3/4". The washer-like pieces are the tops of the caps. I made those a couple of days ago by drilling a 7/16 hole in the center of a stack of square pieces and then turning them round to the OD of the tubing.

 

 

This morning I made a soldering fixture. This is actually the extra blank I made for the oil pump rotor. I chucked it in the lathe and counterbored it 1-1/2".

 

 

Here's the fixture with a cap and the ring inserted.

 

 

Then I coated it with soot using my acetylene torch. Once again, I failed to photograph the next step but I simply put the fixture with the two pieces in it on my camp stove and let it run until everything was up to temperature. Then, it was a simple matter to run a bead of solder around the inside edge. This worked better than it has a right to.

 

 

This is what the pieces looked like when they came out of the fixture.

 

 

I polished the first one and tested it.

 

 

Then spent the rest of the day making the other seven. It took a lot of time because I had to get everything up to temperature to solder and then let it cool so I could handle them so much of the day was spent waiting and straightening up the shop. But, by the end of the day, I had eight dust caps.

 

 

 

 

 

Edited April 26, 2019 by JV Puleo (see edit history)

[Luv2Wrench]

Wow, that looks great and gives me an idea for a piece on the Metz that I wasn't sure how to do.

[Mike Macartney]

Interested about the acetylene soot for the soldering. I use that idea on annealing aluminium but have never thought of using the idea on brass for soldering. The valve caps you made look great. I like the idea of the soldering jig.

[JV Puleo]

This morning I put the original camshaft back in the engine to see if the new caps affected anything. When I made the lifters - two or three years ago, I took the measurements from one of the originals. They were crude and in poor condition and one of them was broken. If I remember correctly, they did not have dust caps. Sure enough, the actual lifter sat a little too low in its housing when in contact with the cam. So I spent the day dismantling the lifters and taking .100 off the top edge of the housing. This is what they look like taken apart...

 

One thing I do occasionally have second thoughts about is the rollers. I purposely didn't harden them thinking that if they wear they are not difficult to make while if they wore the cam, that would be a real headache. Several of the original cams (from this period) that I've handled showed serious degradation of the hardening - with it coming off in flakes. I suspect that was because they were using mild steel and case hardening it. It probably isn't a concern today so I may revisit these at some point.

 

 

I didn't try to copy the originals exactly. I read what Heldt had to say about them and went by his suggestions. The lifter itself is hollow and the slot you see there is for a dowel pin. The pin serves to prevent the lifter from rotating and to keep it from falling into the crankcase if you remove the adjusting nuts. That was a fault in the original design and the Mitchell owner's manual, which has very little useful information in it (most of it is devoted to teaching the new owner how to drive) actually mentions this and warns against taking the lifters out for that reason. At the time I made these I didn't have the expanding mandrels I use so often nor had I made the dial indicator modification to the lathe so, while they are good, they aren't as good as they would be if I did it today. I'd have preferred to make them out of bronze but the cost of that much bronze bar was more than I could handle at the time.

 

The job went well, even if it did take most of the day.

 

There is still more to do. I want to make some little brass rings to retain the dowel pins. Then I have to make the hold downs. I set the pieces up on the engine to take some measurements because this time I am not going to presume that everything matches.

 

Edited April 26, 2019 by JV Puleo (see edit history)

[Terry Harper]

Hello Joe,

 

That's an interesting design for the lifters. On the Wisconsin the slot in the lifter guide (that the roller rides in) keeps the lifter from rotating out of alignment with the face of the cam lobe.

The brochure states that the cam lobes are heat treated, hardened, ground and keyed and pinned to the shaft. While the rollers and pins are "hardened steel". The lifter bodies are also

hardened and the adjustment screws are case hardened and the top face ground. The pin is an interference fit.

 

The top of the lifters are dished with an oil hole angled down to a hole bored completely through the axis of the lifter and threaded for the adjuster screws. An oil groove runs around

the circumference of the lifter with an oil hole connecting to the center passage. The idea of the oil hole to the dished top is to provide a "oil mist" to lubricate the valve stems - these

being enclosed with aluminum shrouds. The bearing bronze lifter guide also has oil grooves (around the inside circumference near the top of the bore and vertical)

 

Anyway, not sure if this is useful or not!

 

Best regards,

Terry

 

 

 

 

 

Edited April 27, 2019 by Terry Harper (see edit history)

[JV Puleo]

Using the slot in the lifter housing as the guide was how the originals for the Mitchell worked but the housing was cast iron. When I decided to make them out of aluminum I as worried about the roller galling the softer material if I relied solely on the slot. If I could have made the bodies out of bronze I'd have just used a screw and a single slot to keep the lifter from falling into the engine.

 

It's interesting that your engine uses a multiple piece cam. They were the preferred method for high-quality engines made in smaller numbers. I'd really like to make one... but as yet I haven't figured out a way to grind the lobes. In period they made a cam grinding attachment for a cylindrical grinder that would do one or two at a time but I've never seen anything buy a drawing - if I ever found one I'd have to buy a grinder too.

 

The rollers on my 1910 REO were hardened and I seem to remember the hardening was breaking up. I know I replaced them. The rollers on the original Mitchell cam followers were hard but badly worn on their pins. Both of the original Mitchell cams I've had in the shop showed a lot of surface degradation. I guess the best solution is to find out how hard the cam is and then make sure the rollers aren't as hard.

[Terry Harper]

Hello Joe,

The spalling on the cam lobes brings to mind one of the issues with the early Studebaker V8.

Early on they had a lot of issues with damage to the cams. Part of it was lubrication but a large part was the increased

contact load due to increased valve size and weight, and the need for rather stiff springs to keep the whole assembly in

contact at high RPM.

 

I wonder with the large heavy valves and hefty lifter assemblies used on these T-heads  combined with

poor heat treatment if that could be similar though at much lower RPM.

 

On my engine the cams show just a bit of surface damage but the rollers are perfect.