My 1910 Mitchell "parts car" project

[JV Puleo]

Volvo and Mercedes both had major camshaft problems in the 70s. I was working at a Volvo dealership in those days and I think our service department was replacing 5 or 6 camshafts a week. The mechanics were paid flat rate, under warranty, for a job that was supposed to take all day - if not longer. One of the mechanics figured out a way to replace the cam without taking the engine out. He made his own tools and had the job down to about 2 or 3 hours - he could do 2 or 3 a day. The owner loved it... a person could drop their car off in the morning and pick it up at lunchtime. As a result, he got all the camshaft jobs and made so much money that year that he quit and started his own garage.

 

I hadn't thought about the weight of the reciprocating parts but of course, that is a major issue. All those parts on my car will be substantially lighter than the originals which leads me to wonder if my unhardened rollers may last longer than I anticipated. My guess is I'll never be able to drive the car enough to wear them out. I did make them out of Stressproof - commonly used for gears and other high impact purposes.

[JV Puleo]

I also wanted to make 8 brass rings to make certain the dowel pins can't move. This is more complicated than it would seem because they need to be 3/8" tall. I had to think about this one but this morning I went in and cut rings that size using the cutoff tool.

 

 

All well and good - that was easy.

 

 

But, the cutoff tool leaves a small burr on the inside edge and removing it without damaging the rings is a challenge. I have to thank Spinneyhill for the next idea. I was thinking about the split bushing made by holding them together with a hose clamp and decided to make a clamp to hold the rings.

 

 

A piece of aluminum bar with a 1-1/2" hole in it... then I milled a slot.

 

 

I had planned to use a hose clamp to tighten the clamp but when the slot was milled the piece closed up very slightly so the rings were actually a fairly tight fit.

 

 

The clamp held 4 of them so this was another example of taking 2 hours to make the tool and 20 minutes to do the job. With the rings in the clamp, I honed them out with a wheel cylinder hone. The first one fit perfectly.

 

[Spinneyhill]

3 hours ago, JV Puleo said:

I have to thank Spinneyhill for the next idea

Hey, steady on! What could I possibly have said to give you an idea? You're The Master!

[JV Puleo]

I hadn't thought of using a hose clamp. In the end, I didn't have to but that was the idea when I started. Actually, the hose clamp would have been necessary if I was machining those pieces. As it is, honing doesn't put any appreciable pressure on them.

[JV Puleo]

This morning I finished up the rings on the lifter housing. Only one had to be tweaked a little so the ring would slide down. Then I had to shorten the dowel pins a little but that was easy.

 

 

I then took them out to measure the distance between the holes. I have this neat tool (bought because it was cheap and sounded like a good idea...) a Sorensen center finder. It measures the distance between the centers of two holes.

 

 

But... I've never mastered reading old fashioned vernier scales so, while I had a measurement, I wasn't comfortable with my lack of expertise in this area. so, I measured them with my dial vernier caliper - the maximum distance less the diameter of one hole. That should give the same result. The difference between them was small - a spread of .005 so if I aim for the middle and make the holes .010 over, they should fit. I milled my four blocks of aluminum square on one end and also made a "gage" block. Getting all four identical is a challenge so I decided this is one job where I'll make a prototype. If it works, all well and good, If it doesn't, I've only ruined one piece. This is the gage block, using the mill to get the center holes the exact distance apart.

 

 

Then they were drilled and reamed.

 

 

The gage block is clamped to the workpiece between two angle plates to keep them absolutely parallel. Then I used a transfer punch to locate the holes. I've drilled two of the holes but while doing it I thought that I really should have used a center drill the exact diameter of the hole in the gage for this rather than the transfer punch. It's too late to go back and do it again but I will do that for the next ones. For now, I'll bore the holes in this one and see if it fits.

 

 

 

 

[JV Puleo]

Today I drilled and reamed two 1" holes in the block. I reamed the holes in order to get the most accurate surface possible to center the spindle for the boring head.

 

 

The centering worked fine. I had a strange problem with the milling machine, one I've never had before but I think that's taken care of now. The holes were bored to 1.510.

 

 

And... they didn't fit or at least didn't fit as precisely as I'm looking for. I think my measurements are fine but I now think the various operations weren't done in precise enough manner. The more operations there are - and the more tools you use, like the vise's that held the part in both the drill press and the mill, the more it will vary a few thousandths. I could use this part - the holes are about .020 too close together but since I have to make the other three, it's little more work to make four more. This time I've eliminated the vise from the equation and clamped the piece directly to the drill press table to drill the center hole. I've also used this long center drill to start the hole rather than the transfer punch I used the first time. I am certain this is more accurate. The center drill is exactly the size of the reamed hole in the gage block while the angle plates the pieces are clamped between make certain everything will be in line.

 

 

 

After all the center holes were drilled and reamed I repeated this operation for the lifter holes but this time I put the 7/16 transfer punch in  the center hole so that the pieces cannot move in any direction.

 

 

Edited April 30, 2019 by JV Puleo (see edit history)

[Mike Macartney]

Joe, you can call me 'thick' if you like, but what is the part you are making and what is it for? Whatever it is, it is very nicely machined.

[JV Puleo]

You don't recognize it because it looks nothing like it will when done - and about 3/4 of the metal is removed. they are the "hold downs" for the lifters... bolt to the crankcase and each one holds two lifters in place.

 

 

[Mike Macartney]

Thanks for explaining. My excuse is that it was 6am this morning when I read your post!

[JV Puleo]

This is one of those jobs that is turning out more difficult than I anticipated. I've spent yesterday and today fiddling with ways to do it. I'm finally making some progress. This is what I was aiming for...

 

 

The stock is too thick - I changed the design after I'd bought it and, of course, most of it will be removed. I think about 2/3 of this will be gone by the time I'm done.

[Spinneyhill]

In that case, cut it in half and you will have two!

[JV Puleo]

Unfortunately, it's only 1/4" too thick. I think this will go down as one of my over complicated designs. They will be nice though - if I can do it.

[JV Puleo]

Believe it or not, this represents most of today's work. At least they fit correctly. The next step is to tidy up the hole in the center. It is critical that it be in the exact center because I will be milling it round using the center as the registration point. For that I need a long 1/2" end mill which is supposed to be delivered on Monday. Until I get it, I can't move the vise or the table on the mill because I don't want to disturb the alignment.

 

[JV Puleo]

Jeff,

Just before I left tonight I decided to mic the web between the two holes... three were .858 and one was .859 so it looks as if my method was even more accurate than I'd hoped for.

 

jp

[Mike Macartney]

Joe,

 

I am trying to become more accurate with my machining after following your posts. Is it possible to show us how you measured between the two holes? I have problems when I try to measure between two curved surfaces. My measurements never seem to come out the same each time I measure the same part, especially when trying measure a hole in a bore, when I am trying to get it to a certain size in the lathe. To overcome this problem I tend to make a 'plug' of the correct diameter to try in the bore.

 

Mike 

[JV Puleo]

It isn't easy...

One took I've found very useful is the telescoping gage - for measuring the inside of a hole. They are fairly expensive new but readily available on ebay used and reasonably cheap. The arms spring out and you can measure them with a micrometer or dial vernier.

 

 

As far as setting the distance between the two holes, moving the table on the mill proved to be, by far, the most accurate. The first hole was located - the dial at the end of the table set at zero and when the first hole was bored I just moved the table. None of my other ideas worked as well. The trick here was getting the hole in the middle in the right place and I was not 100% successful. I will correct that on Monday or Tuesday but if I had to do it again I'd have set the piece up in the mill, drilled and bored one hole then moved the piece down and done the other. I would not put the hole in the center until I was done boring the large holes.

 

jp

Edited May 4, 2019 by JV Puleo (see edit history)

[Mike Macartney]

Thanks Joe. I have just realised I do have a set of telescoping gauges  Perhaps I better start using them!!

[JV Puleo]

Our local weather report predicted rain today so I put the charger on my lawnmower and came into the shop. Of course, it hasn't rained and now the prediction is that it will rain tomorrow. So... I cleaned up the milling machine (I hate working in a pile of chips) and gave some thought to the rest of the job. One problem I have is that I've outsmarted myself a bit. The original lifters were kept from turning in their holes by a small dowel pin through the rim of the housing into the crankcase. I couldn't think of a way to drill that hole accurately - since none of the measurements are consistent on this engine. So, I designed a system where each pair of lifters would lock to each other. Since then, I've thought of a way to do it but I'm committed to making the pieces for the system I designed if only to keep everything looking complete. What I wanted was a cross-shaped piece on the bottom of the hold-down that would engage a notch in each lifter with a straight section in the middle that would be up against the lifters.

 

 

I'm still thinking about how to make these and attach them to the lifter hold-down but in the meantime, I set up the next operation - putting the hole for the hold-down stud directly between the two big holes. Were I to do this over (God forbid) I'd have put this hole in last but this will work too. The first step was to locate the hole exactly. I did that by finding the edge of the first big hole. This is a piece of 1/2" ground stock, held in a collet, painted with layout fluid.

 

 

I start the mill and move the table very carefully until the edge just scratched the red dye.

 

 

Then the table is lowered and moved over .250 (for half the thickness of the ground stock) + .4025 (half the distance between the two holes). This should put the hole directly in the center give or take .001 which is plenty accurate enough. I use this system for edge finding even though I have a "store bought" edge finder as it seems so much easier. It is probably not aerospace accurate but more than good enough for automobile work.

Edited May 4, 2019 by JV Puleo (see edit history)

[JV Puleo]

To my relief, the long 1/2" end mill came in this morning so I was able to fix the center hole.

 

 

Then it occurred to me that all I had to do to center the remaining holes was to put the piece of 1/2" stock in the collet and push the piece over until it touched...which made doing the remeining holes a cake walk.

 

 

The next step is to mill abut 1/2" off the ends. This is to get a surface to hold the piece down to the rotary table. I confess I hadn't thought about this ahead of time and I'm hoping that there will be enough friction between the piece and the top of the table to keep it from moving.

 

 

All done... tomorrow I'll set up the rotary table and it will be a lot clearer what I'm making here.

 

[JV Puleo]

I set the "test piece" in the rotary table this morning and began milling.

 

 

An inch of the material is removed around the boss in the center.

 

 

Then it goes in the lathe to have the ends turned off.

 

 

This is what it should look like. It's obvious I didn't center it perfectly so I'm glad I had this one to experiment on.

 

 

And on the engine. The boss in the center will be reduced but I need the studs that will hold them down first as I want to use acorn nuts on top and need to adjust the height to the studs.

 

[JV Puleo]

The prototype was well worth the trouble. I re-centered the rotary table using a different method - still not perfect but much better. Then I decided to bite the bullet and use one of the pieces with the holes in the right place. I followed the same routine but this time, while the centering wasn't perfect, it was closer. After I'd machined the part I decided that there wasn't enough clearance between the lifters and neck of the hold-down so I put it back in the lathe on an expanding mandrel and turned the neck down to 3/4" - which is actually the dimension I'd intended to use when I designed this. This trued everything up and I'm reasonably pleased with the result.

 

 

The radius at the base of the neck is made by using a 1" end mill with a 1/4" radius. I bought 3 of them to use when I make the connecting rods so I'm hoping I don't wear them out before I get to that job.

[weathered1]

Joe, nice job. Great to see the whole progression. Thanks

[Mike Macartney]

8 hours ago, JV Puleo said:

The radius at the base of the neck is made by using a 1" end mill with a 1/4" radius.

 

Joe, when you did this machining did you rotate the rotary table by hand to remove the metal? Sorry for the questions but I am trying to learn from your excellent posts.

[JV Puleo]

Yes. I don't have a powered rotary table. Actually, I've only seen them on bigger machines like a P&W vertical shaper. I think you might be able to power a rotary table (I know you could power a dividing head) on this machine but it would require all the extra bits it originally came with and that I've little chance of ever finding.

 

j

[Mike Macartney]

Thanks for that. I wasn't sure if you rotated the table or plunge cut and kept moving the table around. I shall now dig my rotary table out from where it has been in the cupboard for the last 10-years and put it with the mill for future use. Yet another machining tip I have learnt from your excellent posts. Mike 

[JV Puleo]

You could never go that deep and rotate the table - at least not with my machine. I'm not sure what the optimum depth of cut for a 1" end mill. I seem to remember reading somewhere that it is 1/2 the diameter of the cutter but I didn't even try that. I took these down .050 at a time.

[JV Puleo]

Today I milled the remaining three pieces. I decided to go only 3/4" deep because with the neck in the center turned concentric with the center hole I can hold them in a collet and it is a lot easier to take the thickness down from the bottom.

 

 

Then I put them in the lathe and removed the excess material on the ends. Tomorrow I'll reduce the thickness of the bottom end to 3/8" so they match the brass rings on the lifters.

 

[alsfarms]

Your thinking, planning and execution are all great!  Nice end results!

Al

[JV Puleo]

Today I reduced the base of the hold-downs to 3/8". Had I made them from thinner stock, this would have gone faster. Still, the finished height is 1". I would have used 1-1/4 thick stock if I had one of these finished ones to copy but I'd bought 1-1/2" and didn't want the expense of buying it again. Still, it probably didn't add much time to the job. The reall time killer is the experimental stage - doing something you've never done before is like that.

 

 

With that done, I put them back in the lathe and trimmed the tops so that they are all identical in height. This is important because I want to use acorn nuts to hold them down so I have to get a consistent length for the studs - which I'll also have to make because I can't seem to find any that fit my dimensions exactly.

 

 

there is still a little more to do but I'm waiting on the materials. Tomorrow I'll probably go back to the oiling system.

[alsfarms]

Hello Joe,

Yet another step on the road to recovery of your Mitchell.

Al

[JV Puleo]

While I'm waiting for some pieces of aluminum I assembled the oil manifold. The first step was to solder a threaded bushing into one end.

 

 

The bushing was a little long (intentionally) so I then put the entire piece in the lathe to face it off. When doing this it is always a good idea to work from the inside out because you will inevitably create a little burr on the end and it is much easier to take it off the outside than the inside.

 

 

I still got a small burr which can be a problem because you can't thread the piece in and it isn't easy to clear it. To do so, I used a big countersink to put a chamfer on the inside edge. I probably should have done this first.

 

 

With that done, I soldered the pressure relief valve into the other end. The goop you see here is heat blocking putty.

 

 

Then I screwed in the oil tube fittings and soldered them in place.

 

 

My friend Mike West made a suggestion that I'm going to incorporate into the system - a separate hand pump to get oil pressure before the engine is started. To mount is, I'm making a little piece that will slide over the pump tube from this piece of Naval bronze prop shaft - something I bought cheaply on ebay because the surface is so corroded. I've had trouble working this stuff before and this piece happens to be a part I gave up on. It just happens to be suitable for this job so I gave it another try,.This time I did much better. My problems with this material were particularly frustrating because I've used this stuff before but could not remember how I worked it.  I made several pieces for the B&S milling machine with it.

 

 

After you've removed the corroded layer, it is very nice bronze.

 

Edited May 11, 2019 by JV Puleo (see edit history)

[Mike Macartney]

10 hours ago, JV Puleo said:

The bushing was a little long (intentionally) so I then put the entire piece in the lathe to face it off. When doing this it is always a good idea to work from the inside out because you will inevitably create a little burr on the end and it is much easier to take it off the outside than the inside.

 

Thanks for the tip, these sort of tips are very useful to us who are learning machining.

 

Joe, I think you need an edit on "The goop you see here is beat blocking putty."

I was racking my brains trying to work out what it meant, then I twigged 'Heat Blocking Putty' it's just what I need for my soldering on the Humberette radiator. I found it in the UK from Frosts, they call it Cold Front. I remember using it back in the 70's when I was welding with Oxy/Acetylene, I didn't realise it was still available..

[JV Puleo]

This piece is a threaded collar that will hold the auxiliary hand pump to a bracket mounted on the subframe. This time I thought I'd knurl it first. In this case, I did it on a mandrel held between centers because of the amount of pressure that will have to be exerted to make the knurling wheels cut.

 

 

It came out pretty good and because I'm reducing the diameter on one end I didn't have to worry about where the knurl stopped.

 

 

I then flipped it around and turned most of the diameter down to 1-1/2" with a relief for the thread - which will be 1-1/2-18 - chosen because I have a tap for that size and, with the thin wall of this piece you want a fine thread.

 

 

In order to go on with this, I need three more threading gages. Two for 1-1/4-20 and one in 1-1/2-18. I'm making those out of aluminum which isn't the ideal choice but I have it and these will only be used a few times. If this were a production environment, you'd want to use steel. It's fairly common for me to use these more than once but if I live to be 100 I still won't be able to wear them out.

 

 

I finished both the blanks... they still have to be bored out and threaded.

 

 

The smaller one was made from another fixture I used for the intake manifold so this is its second incarnation as a tool.

[JV Puleo]

I continued on with the threading gages today. This is going to be the internal gage for the pump caps. I need to make this one of steel because I'll be holding the caps in the lathe to knurl them and I want it as strong as I can make it. The center is reamed to 7/8" - rather than explain why - you'll see when I make the caps. I took a chance and used some "mystery metal" I had 0 probably an old piece of mill shafting. I was concerned it wouldn't thread well but this time I got lucky.

 

 

Here's the finished piece, threaded 1-1/4-20. Because the pump tube has a wall thickness of .065 it is critical to use a fine thread.

 

 

Then I bored out the larger of the two external gages. This one is threaded 1-1/2-18 so the hole size is 1.450.

 

 

To my relief, it tapped quite easily. These big taps can be a PIA - another reason for using aluminum. It's soft enough that it is much easier to tap.

 

 

So, two down and one to go. The tubing still hasn't arrived so if I finish the 2nd external gage I'll get on with the caps.

 

 

This is a classic example of taking as much time making the tools as it takes to make the part.

Edited May 13, 2019 by JV Puleo (see edit history)

[JV Puleo]

I completely forgot that it takes hours for this old reciprocating saw to cut a 2" bar of bearing bronze. Likely the blade is dull but the very properties that make this bronze good for bearings make it a pain in the neck to saw. Luckily I got called away for another job and just left the saw running.

 

 

When I got back, I threaded the collar that will hold the hand pump to the subframe.

 

 

The threads fit the gage just fine.

 

 

By this time the saw had finished one piece so I put it in the lathe to bore. When that was done, and the saw still running, I decided to thread it.

 

 

This fit well as well... and the saw only finished the second piece just as I finished the threading job.

 

 

So, I'll use these threaded pieces as my gage and forget about the aluminum one. The tubing arrived this afternoon so I can keep on with this until it's done.

[JV Puleo]

I finished making the bodies of the end caps this morning...

 

 

I'll make the end of the caps now. For one of them, I need a piece of bronze 1-1/2" long so I put it in the saw and let it run.

 

 

While it was sawing, I cut off a piece of tubing.

 

 

And, because the saw was still running, threaded one end.

 

 

The caps screw on fine but I'm having a new problem. For some reason, the cap won't go past the last thread. I'm guessing that relief isn't deep enough but it's tricky working with this tubing. The wall thickness is only .065 and the threads are about .035 deep. I'm thinking I should have used a finer thread but it is too late to change that. If I have to, I'll find some tubing with a thicker wall. That will decrease the volume of the pump a little but this is only to pump up oil pressure before I start the engine so a few extra strokes with it are inconsequential. If this one works out, I'll get about 5 cubic inches of oil per stroke so it shouldn't take too many to fill the oil system.

[46 woodie]

Joe, you are one talented guy! I am amazed at not only your machining skills, but your ingenuity in fabricating fixtures to hold the part you are making. The sad part is that once our generation is gone, there is no one to pick up the ball and run with it. I'll bet there aren't a dozen young people in America that can do your quality of work. Most kids today don't know an end mill from a reamer. Please keep posting pictures of your incredible workmanship!!!

[Lahti35]

Those old power hacksaws are great for cutting while you go and work on something else, slow but steady! I've got a Marvel 9a myself.

[JV Puleo]

I'm not so sure though that might just be my natural optimism showing. Remember, I'm almost completely self-taught and, for the most part, the shop has only been assembled over the past 6 years. I've hardly ever paid more than scrap price for a machine so the argument that it's too expensive to do doesn't' hold up. It does take time, determination and interest in the subject – and the willingness to read a lot of old books but I suspect there are young  (or younger) guys out there who are doing all that. In fact, I know at least one in my neighborhood and he's a car guy too. I wonder if there were ever many guys doing this sort of thing - there certainly weren't any I knew when I was first involved with antique cars 40 (nearer 50) years ago. Probably 80 or 90% of what you see here is stuff I've never done before.

 

And yes, the beauty of the old reciprocating saw is that you turn it on and it turns itself off when it's done. It's only a problem when you don't anticipate how long it will take.

 

jp

Edited May 16, 2019 by JV Puleo (see edit history)

[JV Puleo]

I started the day by threading the other end of the brass tube. I had a problem with this threading job... in both cases, the cap would not screw on all the way so the relief for the end of the thread showed. I suspect I did not cut it deep enough but I was very reluctant to cut it any deeper because I was already half-way through the wall of the tube.

 

 

So, I decided to counterbore the caps.

 

 

This worked just fine. In fact, if I had thought about it, I would have made the caps this way.

 

 

I admit I had second thoughts about the use of bronze for the caps and brass for the tube, but I was using what I already had. Then I thought to look at the original hand air pump I have - and discovered it has a brass tube with bronze mountings so I guess I've accidentally done it the right way.

 

 

The next step was to make the inner part of the top cap. This one is more complicated than any I've done before because it will incorporate a bushing to guide the rod in the center and have a threaded socket on top so that the pump can be secured when not in use.

 

 

It was drilled and reamed to 11/16.

 

 

I don't have an expanding arbor in that size so I turned the diameter down to 1-1/4 (the major diameter of the thread) on a mandrel, Then turned one end down to 1-1/8" which allowed me to hold it in a collet so I could face off the other side.

 

 

This end was now turned down to just over 13/16. A bushing will eventually be pressed in here while the other end will be threaded 3/4-16.

 

Edited May 16, 2019 by JV Puleo (see edit history)