JV Puleo

My 1910 Mitchell "parts car" project

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That's an expanding arbor – one of the best lathe accessories I've ever bought. They are made by this company: http://www.breakhearttool.com/

There are some cheap import imitations of the smaller sizes which would be ok if they didn't use expansion screws that must be made from soap. I broke down and bought the better quality ones and it was worth the expense. That said, I've no problem with cheap tooling, especially if it is something that will only be used once or twice a year but, I find I'm using those arbors as often as I can. Now... they can slip if there is too much pressure on them. I will be turning the exhaust manifold flanges on this same fixture and I think I will put it in the 4-jaw chuck for that. I made the effort to turn the OD absolutely concentric with the ID so that either surface could be used it set it up.

 

Cheers,

 

jp

 

Edited by JV Puleo (see edit history)
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Nice Job Joe,  Just one more little project out of the way.

Al

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I turned the first of the intake flanges today. This is a much more difficult job to do than it should be because the Mitchell did some really shoddy machine work. The hole spacing on all of the flanges is different. They got around that by just drilling all the holes in the attaching parts about 2 sizes bigger than they should be or, I suspect, drilling two parts at once so that even when they were wildly off,  things would still attach. Of course, when you don't have the original part, it a lot more difficult.

 

Well... I finished one flange and bolted it on. It fit just about perfectly - and then I noticed that the mounting holes are about 1/4" off center from the intake port! I really have to think about how to approach this because, as it is, the intake flange actually obstructs part of the port. I'd write them a nasty letter but they went out of business around 1924. Given the quality of their work, I'm not surprised. The next time you hear "they don't make them like they used to" think of this... there was a lot of slipshod work in early cars.

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Joe, I think that's rather typical. On my big Wisconsin, which is supposed to be high quality, one of the studs for the intake manifold on the middle cylinder block is way offset from the centerline of the port as well. The funny thing is almost every one of the PT series engines I have examined has the same issue - all the intake manifolds have the same hole enlarged and offset yet each of the blocks

is supposed to be interchangeable.

 

 

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I was pretty tired when I discovered this new headache and I confess I'm not at my best after 6 hours in the shop. I'm old enough now so that standing up for 6 hours leaves my back hurting. Tomorrow I'll look more carefully but I am inclined to put the blocks back in the milling machine and bore the intake ports round. Then plug the bolt holes and re-drill. It's a lot of work but that would be the really elegant fix and as much work as it is, it is a lot less than if the engine was all back together. I know that if I don't fix this, it will continue to bother me.

 

 

Edited by JV Puleo (see edit history)
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Terry, Do you think I'm overdoing this? I have a tendency to get carried away with precision.

The good thing is, that if I rebore the ports and redrill the holes I can still use my elbows... I'll have to make new flanges but I've already made all the tooling so that isn't as big a deal as starting over.

Edited by JV Puleo (see edit history)
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Hello Joe,  Our hobby is driven by our skills (whatever they be).  There is absolutely nothing wrong with sorting out the original machine work and make it better for the next caretaker of our cars.  I must admit, I have been confronted with similar little "pains in the behind" issues and have simply jumped into a better repair that will let me sleep at night!  Terry, on your Wisconsin center jug "glitch".  I have not scrutinized my Model "M" but plan to in the next day or two and determine if I have a similar problem.   I do have a long shot thought on the issue that you have suggested that has been on every "PT" series engine that you have looked at.  Do you think that it may be some form of design to limit the thermal growth from the center jug and effectively force a small degree of thermal growth in both directions?   If the issue were simply a "random" boo-boo during the machine process, you would think that the problem would be evident on the other jug locations being front or rear.  Just a thought.

Al

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Hello Joe,

We all have varying degrees of "good enough" Some people are satisfied doing the least amount possible - others - like you, (and me to a more limited extent) have to do the job to the uppermost limit of their experience and skills sets. For some of us that challenge if you will and need to achieve perccision results is all part of the fun and satisfaction. For example I have a friend who has been building an experimental aircraft for the past seven years. Achieving a phenomenal level of craftsmanship  and the act of building is a passion for him that trumps the actually flying!

 

In the pragmatic approach are you really gaining any value by going the extra bit in this instance? Probably not. But, you are building a new manifold which is the perfect time to go just that extra bit more to correct a fault. The stud - yes - but I don't think I would worry to much about the ports being out of round. In fact, I am think about the same approach - plug the offending hole and drill a new one.

 

Alan, I am not sure. You would think that each jug was gang bored using a fixture so they would be all the same. I do know that at some point they changed from a elaborate cast aluminum manifold to the assembled brass.

 

 

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I took another serious look at the jugs today... as I've said before, I shouldn't make important decisions when I'm tired. Only one of the ports is badly off center, the front intake port. The others are all quite close, or at least close enough so that I can't see making any worthwhile improvement. Here's the bad one. The scribed circle has a diameter of 1-3/4" so it is .100 larger than the finished size should be. There is plenty of metal at this point so I should be able to bore it, provided I can set it up properly in the mill and there is enough room under the spindle for the boring head. I think there is. I have a big angle plate to bolt the base of the jug to so if it fits, I can be sure of getting it exactly perpendicular to the base.

 

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Though the photo is badly overexposed, this is the other intake port. You can see it is reasonably well centered. I think I will make the flanges over. I wasn't all that thrilled with them in any case as I made them out of some brass I had when all the other manifold parts are bronze. Thankfully, this will be an easy pattern to make. I'll change the design a little to incorporate ideas that came to me while machining it.

 

IMG_0463.thumb.JPG.07b426e6a38a53ea25e59e4ee99596b5.JPG

 

I have two different stud measurements to work with. I'll just live with that. The exhaust ports are pretty good (oddly enough, I drilled 3 of the 4 holes) and those mounting holes have to be oversize in any case to allow for the manifold expansion. The mill is all set up to drill the flanges so I'm going to make the two for the exhaust manifold and the pattern for the new intake flanges before going on to anything else.

Edited by JV Puleo
typo (see edit history)
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hmmmm Joe,  You have pointed out some machining flaws for sure.  I really want to scrutinize the Wisconsin before I get down to the machine work needed to build my intake manifold.  Let us know where your machine work resolution takes you on this issue.

Al

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I think a Wisconsin engine might have its odd 'oops" that they let go but I doubt they were as slipshod as Mitchell. This isn't the first thing like this that I've noticed. It's just the worst. There are a dozen more things I wouldn't be caught dead doing - nor would any really competent mechanic in 1910. As my friend Mike West has said "It's a car that dosen't deserve its reputation."  That said, at least they couldn't use really lousy materials... zmac hadn't been invented. If it had, they have used it everywhere

 

So far, it is only the engine I've had this problem with. In order to stay competitive, they severely dropped their prices while trying to keep their "big, medium size car" image and I think all the savings came out of the engine. This engine was only made for two years, 1910 and 1911 - which should tell us something about the quality of the design.

 

And... I'm only going to go in about 3/4 to 1". I don't want to hit a water jacket and this is, at best, a compromise solution. There nothing I can do about a casting that should have been rejected. I'm just going to try to make it as good as it can be - maybe not as good as it should be.

Edited by JV Puleo (see edit history)
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Heavens no... I still have to make the connecting rods and finish the pistons (they are about half done). Then I have to make a water pump and an oil pump and bronze shells for the main bearings. Which reminds me... what drives the oil pump you have on the Locomobile? I'd be really interested in the design if it is something I can adapt to this engine. As it is, I was thinking of making a plunger pump to run off the pump lobe on the camshaft. The original cam didn't have that lobe but the gentleman who made the cam for me added it.

 

Oh yes... and there are the water lines. Those will come after the manifolds because they are all inter-related and must not interfere with each other.

 

j

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Joe, The Locomobile aux. oil pump system is driven from the back of the cam.  The attached picture of the failed starter/generator test shows a cover over the exhaust cam.  There was also a similar cover over the rear of the intake cam.  It is from that position that this oil pump assembly is driven.  I will try to get a few other pictures and post to give you a better idea.

Al 

IMG_20180306_101741482.jpg

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Al, is the oil pickup inside the sump or does it have an external line that runs from the sump to the pump. I'm wondering what the Locomobile had to begin with. In any case, this has given me an idea. It is certainly a better solution than the one I'd come up with... now to figure out how it works.

 

jp

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Joe,  Here is another view of the aux. oil pump system.  If you look closely at the bottom of the picture you will see the tubing and discharge from the oil pump.  The suction is drawn from the oil pan in 2 different places.  The original drip oiler has been kept in place for esthetic appearance.  The discharge from the new pump system has been diverted through the drip oiler and on to the destinations of the now pressurized system.  This new system has the capability to put out 50 psi.  We determined that the stress on the drive system was too much at 50 psi so the pump discharge was reduced to 25 psi and it floods the system like the drip oiler could only dream of.    I will try to get a few more pictures that show the pump working end with fittings at the oil pan and pump.

Al

IMG_20180306_101753454.jpg

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Joe,  An other note.  The drip oiler box is also used as a reservoir for an extra quart of oil and is included in the lubrication circulation circuit.  We are planning to install an oil filter but that install has not been completed yet.

Al

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Thanks Al. I am guessing that this is a vane pump. In any case, I'm working from that assumption and designing something that will go on the back of my engine in place of the big rear camshaft bearing holder. I won't be able to run through the drip oiler because it ran off a belt to the front pulley and is on the opposite side of the engine, at the front. That isn't a problem... I don't care if it is esthetically  perfect and I'm going to put a generator or alternator in that spot, though disguised to look like one of the period dynamos.

The buttweld elbows finally came in. UPS messed up the delivery and I had to chase them all over town but I finally got them last night. They look like they'll be perfect but there is still a lot of work to do there. I'll try getting some photos tonight.

 

jp

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Here are the two pipe elbows. I really like them. They look as if this was definately the right way to go.

 

IMG_0465.thumb.JPG.3ee6b8141db04a791e1c7f61fb24235f.JPG

 

I often hove several jobs going at the same time - though I hadn't planned on working on the exhaust manifold yet. But, setting up the milling machine to drill the flanges with their erratic sizes was so time consuming that I thought I should at least make the exhaust flanges before I pulled the tooling apart.

 

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I made another threading fixture as well (the photo is out of focus)... I had wanted to use the one I made for the intake flanges but there were some size constraints that upset that plan. In any case, I want to finish the intake before I get too far into this job.

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Joe,  The oil pump used on the Locomobile is a modern rotary gear pump.  The original drip oiling system was a full loss system.  The oiler box held what oil would be used to drip oil the  engine originally.   The Loco pan has a couple of ports, one for low level and one for high level.  If the oil came out the top port you would drain it to the level of the  lower port.  The new system pulls oil from each of the two oil pan chambers with some custom piping.  Then a certain amount of the flow recharges the  drip oiler box and maintains a level their while the rest of the oil pump discharge lubricates the engine.  I am using the dash site gauge to verify flow and be a tell-tale that the oil pump system is working.  No oil at the site glass, stop car NOW.   We have also devised an oil dip stick to function in one of the crank case vent stacks.  I think we may be having the "first start" party, for this engine, in a week or two.  I will also have a few updates on my design for a 12 volt starter/generator coming soon.  This is getting very exciting!   On your butt weld elbows.  My thoughts are still to use the long sweep elbows to move the exhaust out away from your jugs.  What are your thoughts?

Al

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Your original system, and mine, worked in exactly the same fashion so we are dealing with the same potential problem. I've designed a vane pump that will replace the rear camshaft bearing holder. Actually, it is only about 1/2" greater in diameter and the same depth so it will be almost unnoticeable. In going through the 1910 edition of Heldt's engineering manual last night, I realized he describes the type of pump I'm making and says they are "occasionally" used as oil pumps. So, I'm not straying from my goal of keeping most of the modifications in the spirit of the period. I still have to work out a pressure relief valve because my pump will produce exactly twice the volume of oil Heldt recommends based on bearing size. I may even add an auxiliary oil tank if I can find a place for it. The real beauty of this plan is that the pump can be completely tested off the car. I'm probably years from my "starting party" and I'd be very wary of starting an engine with a home-made oil pump that I wasn't sure really worked! Now I'll know.

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Joe,  The Loco oil pump I am using has provision to run it only and not needing to crank the engine.  That is how we are absolutely that the pump is working and working WELL.  We are able to fine tune and set the discharge pressure where we want it (and verify with a gauge).  Not being familiar with your design, most of the vane pumps I have been around have been much larger and were used to develop vacuum.

Al

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Testing it, like you did, is exactly what I plan to do... using a gage and probably the oil distribution manifold that will go on the car. As far as the pump is concerned, I'll post a little more tonight when I get home. The vane pump was invented in the 1870s. The modern ones, for vacuum or in power steering units are much more powerful that the one I'm working on. I've actually had to reduce the size of the parts twice because, when I did the calculations based on my drawings, it moved far too much oil and I'm certain I would have had a pressure problem. Do you know of an in-line pressure regulator? I'm looking but haven't found one so far.

 

j

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Here is the drawing from Heldt. This is c.1910. Notice that there are only two vanes. The difference in size between the rotor and the housing must be very exaggerated because the volume pumped is equal to the difference in volume between the rotor and the housing. I had to reduce the gap, at the big end of mine to 1/8" in order to get the volume down to only two times what he considers ideal for the surface area of the bearings in my car.

 

1690849976_HeldtVanePump.thumb.jpg.c2b9c2bb359e9034552c3bddc6932bc6.jpg

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That is an interesting document.  The rest of the book must be a wealth of information.

Al

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