My 1910 Mitchell "parts car" project

[edinmass]

Thanks for the update........things like this keep me up at night! 👍

Edited April 2, 2020 by edinmass (see edit history)

[JV Puleo]

me too!

[JV Puleo]

In answer to one of Ed's questions, here is one of the original connecting rods. Notice that there was no provision for scoops, just a hole in the bottom of the big end cap.

 

 

And two oil holes on the opposite side.

 

 

 

Before I drilled the holes for the cotter pins I had to make the washers the nuts will sit on. These are MilSpec washers that have a 7/16" hole in the center (unlike SAE washers where the hole is quite a bit larger than 7/16). The OD is 1" - too large for the application but that was easily fixed.

 

 

By making a mandrel out of a bolt and turning them down to .850

 

 

 

Then I put one together to make certain where the hole should go.

 

 

And set my "cotter pin" fixture in the new drill press - which is far better for drilling small holes than the big drill press is.

 

 

I tested the first one...

 

 

Then went ahead and drilled all of them.

 

 

I received an email from the grinding shop saying my special end mills are ready so I'll pick those up tomorrow morning. In the meantime I decided to make a prototype for the studs that will hold the jugs in place. These are much longer and the washers (which also have a 7/16" hole) have to be smaller so I turned some of the MilSpec washers down to .750

 

 

And cut a piece of 7/16" rod for the sample stud. This is a softer, much easier to work material than the grade 5 which, for this purpose, isn't needed. It likely is still stronger than the original studs were.

 

 

What yhou are seein here is the end of the stud that passes through the top of the crankcase and is locked in place with a nut & washer on the inside.

[JV Puleo]

My idea fr the rear main bearing. The front main would be the same although the length is slightly different. The wall thickness of the shell is 5/16" less the thickness of the Babbitt. These dimensions could change slightly but this is about as big as I dare make it.

 

Edited April 3, 2020 by JV Puleo (see edit history)

[Bush Mechanic]

Just thinking out loud here, Joe. Would the small section of un-oiled babbitt cause a problem. Perhaps not, although that dry outer face looks like a potential thrust surface. The seal would certainly be more secure located inside than it would be if flush with the end.  

 

 

Edited April 3, 2020 by Bush Mechanic
clarification (see edit history)

[Mike Macartney]

A lot to read and take in this morning. Another new one on me "mil spec". I looked it up, now I know it means US military specification. Looking on the internet I could not see a similar military spec for the UK. I was surprised at the large diameter of the lower hole in the big end cap.

[edinmass]

Joe, what you have drawn will be an issue........you can't square off the flair on the end of the crank facing the flywheel flange.........it's has a radius to prevent cracking............that can not be removed......you're going to have to make the bronze meet the profile of the flare....not easy, but if the outer area is large enough, you don't necessarily have to have contact there.......but it would be a good idea. That same applies to the crank throws if you are planning on turning it........to be honest, with only three bearings, I don't think I would turn it down anywhere........I would just polish it and match each bearing to each main..............have you placed the crank on a pair of V block stands and pushed down on the center to see how much deflection you have? It would be a good time to check to see if it's straight also........inquiring minds would like to know! 👍

 

 

PS- Being as anal as I am, I would figure a way to lubricate the thrust face each time I start the car..........may or may not make much difference, but I would sleep better at night knowing it's there........

Edited April 3, 2020 by edinmass (see edit history)

[JV Puleo]

As to the radius... it isn't in the drawing because I did it in the graphic design program I design books with. It doesn't have a good way of making a radius but  have been giving a lot a of thought to how to machine one. It doesn't show in the pictures but I suspect the crank was rusty and was bead blasted and painted with primer. The surfaces are not good enough to just polish but it doesn't look as if it has ever been ground...certainly the original bearings look untouched and the crank fits them reasonably well. In fact, on at least one journal it seems to be a bit too big which makes me wonder if it's the crank that came out of this engine.

 

We have a very good engine shop in nearby Mass. They bored the blocks and, in talking to them I came away feeling they were extremely competent. They aren't one of those places that only knows SBCs. I spoke to them about the crank so I'll probably take it back there when I am done fitting the rods. There is a chance I could have the journals welded and reground slightly larger than they are but that would be a function of how much they would have to be ground to get them round and smooth. Pathological as I am, there are a few things that I'd just as soon have done by someone who does it often...

Edited April 3, 2020 by JV Puleo (see edit history)

[JV Puleo]

I've just had an idea re the radius... Use a shell mill made for a 1-1/4 diameter holder mounted on the boring bar. (This is something I've done before so I know it works) The end of the shell mill has to be ground with the radius so it can be advanced into each end of the bearing very gently. If I get a chance, I'll draw another picture.

 

 

Edited April 3, 2020 by JV Puleo (see edit history)

[JV Puleo]

Thinking about the thrust face... I have some small adjustable drip oilers. I could use one of them to get a tiny amount of oil to the thrust face. As it is, I'd planed to use one to lubricate the throw out bearing. I'm not sure how I'd plumb it but I see no reason why it wouldn't work. I expect the parts under the car to get a bit oiley in operation. I've never seen a brass car yet that didn't or, it it was completely clean, it wasn't being driven.

[Gary_Ash]

The "MIL spec" hardware is designated as NAS type, though the older AN designations are still available.  These are strong, high quality bolts and screws usually used in airplanes but now also in race cars, etc.  An advantage is that the shank diameters are tightly controlled to 0.001-0.005" less than the nominal size.  For each shank diameter, the length of the threaded portion is always the same, but the bolts can be bought in 1/16" or 1/8" grip length increments.  As Joe mentioned, the matching washers have tight i.d. control and have a radius on the i.d. edges to match the radius under the bolt heads.  The bolts are also available with heads and/or shanks drilled for safety wires.   The NAS hardware is used when you want a truly precision fit - like a spring bolt through an eye bushing - as well as high strength and a defined grip length.  Ratings differ for shear versus tension applications.  You can buy a broad selection of these through places like Aircraft Spruce or Pegasus Auto Racing, AN sizes to 1/2" or 5/8", NAS sizes up to 1" diameter.  Be prepared for prices much higher than Grade 8's.  

 

Here's some info on AN screws and bolts:  https://www.pegasusautoracing.com/document.asp?DocID=TECH00095 

[JV Puleo]

Ed and Bush Mechanic got me thinking about oiling the thrust so I dug these out... a pair of little drip oilers. I'd thought to use one for the throw out bearing but I could use two and run a very small oil line down to the thrust side of the rear main bearing.

 

 

This is the original throw out... Notice the extreme wear on the thrust surface. It doesn't look like they made any attempt to lubricate it or the original owner rode the clutch all the time. Actually, I think both are probably true.

 

 

I finished my prototype stud too...

 

 

To get a final measurement I screwed it into the crankcase and put a nut on. It's about .150 tall so I trimmed it down.

 

 

Then I tried the stud with one of the jugs. It was also about .150 to .175 long so I trimmed that end.

 

 

And got it just about right. I made the brass flange nuts a long time ago. They were originally intended to hold down the valve cages but I decided bolts were a better choice there so, having made 8 of them, I made 4 more to use to hold the jugs down. I put a Bellville spring washer under the nut but in looking at it I'll probably go with conventional lock washers which are more appropriate to the period in any case.

 

 

The finished stud after both ends were trimmed.

 

 

I also picked up a couple of custom ground end mills this morning and was able to ask about the cutter I have in mind to make the radius needed on the bearings. He didn't think it was a problem. All I'll need are the dimensions and the radius.

[edinmass]

The throw out bearing on a brass car is so easy to change, I would just modify the set up to take a modern sealed bearing, and forget it for the rest of my life. I like the drip feed setup..........please do me a favor...........PM me the shop you would like to use for the crank. Best, Ed.

[hursst]

Amazing work.  You guys make my work look like I'm building a snap-together model.  Great to show how this is work done, and how it still can be done with the right tools and knowledge.  There's still a great need for these skills, albeit among a relatively small amount of enthusiasts.

[JV Puleo]

1 hour ago, edinmass said:

The throw out bearing on a brass car is so easy to change, I would just modify the set up to take a modern sealed bearing, and forget it for the rest of my life.

 

That's the plan, though I hadn't thought of a sealed bearing. There is a bit of a complication in that this ring fits over a flange and pushes it back. There is't any way to get it over the flange unless it comes apart. However...I'm not happy with the clutch either...it's stamped steel and I cannot think how it could possible be in balance - it's bent too. I'm thinking of making a new cone. I can make a pattern and have my neighbors cast one. There's no way I'd put this piece back.

Edited April 4, 2020 by JV Puleo (see edit history)

[Mike Macartney]

18 hours ago, Gary_Ash said:

The "MIL spec" hardware is designated as NAS type, though the older AN designations are still available

 

Thank you Gary for the link. After all these years of being involved with motor vehicles. this is the first time I have come across the term "MIL spec", or perhaps, at my age I have forgotten it!

[JV Puleo]

I'm a little surprised there isn't a British version... or perhaps there is a "European" version for metric fasteners. AN stands for Army/Navy. It was an early WWII development  to regularize fasteners and fittings and get away from the logistical chaos of WWI. SAE sizes are also a result of WWI and the difficulty the services had with all sorts of proprietary fasteners. The later systems are all further developments along the same line.

[JV Puleo]

My friend Mike West gave me a really good idea this morning. He was describing the oil level "tell tale" on an engine he's working on and it inspired me to take another look at my crankcase. The business of checking the oil level by removing a plug in the sump has always bothered me. It isn't the sort of thing you can do easily and the temptation would be to not do it often enough. In looking at the crankcase it noticed the location of this hole... (The one in the middle of the photo. The hole at the right supported one corner of the oiler and the hole on the left held a support for the original cast iron intake manifold.)

 

 

This is where Mitchell attached a line from the box oiler and I'd assumed it was connected to the center main with which it is in alignment. It isn't connected to the bearing at all...it just dumps oil back into the sump. This wouldn't have effected the oiler because box oilers develop a relatively high pressure but with very low volume and have an individual pump for each line. It's an engineering principal left over from very slow turning steam engines. The more modern approach, which was already well understood when this car was built, is to have greater volume and lower pressure. That lubricates the bearing and does a much better job of cooling the bearing. I suspect this boss on the crankcase was intended to hold a rod attached to a float. The location is perfect but there is no hole underneath it for the rod to pass through. This may well be another example of Mitchell's "corner cutting." I think I will make an insert for the hole with a 1/4" reamed hole in it and drill a corresponding hole down through the case so that a float at the bottom will push it up.

 

I also did a bit more on the studs for the top of the case...trimming them all to 3"

 

 

Chamfering the ends an and starting the relief cuts for the threading. The strength of a bolt is determined by the minor diameter - which is why fine thread bolts have a higher torque rating than coarse threads. The relief cuts are .050 deep deep which brings them to almost exactly the minor diameter so despite their appearance, they don't effect the strength of the stud.

 

 

I'll probably finish this tomorrow and start on the threading which will be a relatively easy, but time consuming job but one that, at least, doesn't have the "tension factor" associated with working on the crankcase.

Edited April 4, 2020 by JV Puleo (see edit history)

[Terry Harper]

Here you go Joe,

 

This is the setup Mike and I have. It's a just simple sight glass that screws into the top of the crankcase and has a indicator rod and float.

(very similar to what most home heating oil tanks use) There is a scribd mark on the gauge body that indicates full  - in my case 5 gallons worth of oil.

You could easily downsize it to fit. I bought the gauge glass through McMaster-Carr and cut to length which was the trickiest part. (order extra!)

 

 

 

The only possible problem with this setup is that your crankshaft dips and slings oil which means its agitated quite a lot. The Wisconsin's (at least mine) does not. There is a full

length baffle that separates the crank from the sump (100% pressure lubrication - no dip and sling). You may want to provide a thin brass sleeve (open at the bottom and

vented near the top to protect the float from all the turbulence. The sleeve would also keep the float from wobbling around on the end of that thin rod

and violating the social distancing guidelines of the crank.

 

DANG! Just noticed I spelled "Gauge" two different ways on the drawing!"

 

 

Edited April 4, 2020 by Terry Harper (see edit history)

[JV Puleo]

I have a couple of them but don't know if I have one small enough. I'll look. I suppose I could always make one. I was thinking of something simpler but if I can fit one of those in it would be all the more elegant. The problem is that the aluminum boss on the crankcase limits how big the base and the thread are. The hole there is 1/8 NPT but if I go to that size, how big must the pin that connects to the sump be? I wonder what the inside dimension of the glass is?

 

j

Edited April 4, 2020 by JV Puleo (see edit history)

[Terry Harper]

The rod for the float is 1/16" diameter  The top of the rod serves as the indicator so there is no bead or anything like that.

 

The smallest glass tube McMaster-Carr lists is 1/4" O.D. and .160 I.D.  All you need is enough room for the rod

to slide up and down. I turned and milled  and threaded the body out of Hex stock. Mine did not use an NTP thread.

Probably 1/2" Hex would work.  You will want to have thin rubber washers to cushion both

ends of the glass from vibration.

Edited April 5, 2020 by Terry Harper (see edit history)

[JV Puleo]

Terry, this kept me awake last night. As soon as I finish the laundry I'm going up to the shop to take some further measurements. I think I' getting close to a plan.

[edinmass]

22 minutes ago, JV Puleo said:

Terry, this kept me awake last night. As soon as I finish the laundry I'm going up to the shop to take some further measurements. I think I' getting close to a plan.

 

 

Fortunately I had plenty of crown royal and ice after dinner last night............so this particular problem didn't keep me up. It probably would have taken three or four people to help me stand up........🤢

[Bloo]

This is a 1913 Studebaker "25". There is a wire inside with a little ball at the end. I assume the viewing window should be glass. It is currently a piece of vinyl tubing, a relic of the pre-internet days when I would have had no idea where to get a piece of glass tubing.

 

[JV Puleo]

I found these two sight glasses in my "brass bits" drawer. One is clearly too big but I might be able to make use of some of the smaller one.

 

 

But before I can do anything there, I have to finish the studs I started. I trimmed them all to 3" and put in the reliefs.

 

 

Then threaded them to .005 larger than the finished size and ran a die over them to remove the burrs and make them all uniform.

 

 

And tested them with a nut.

 

 

This is slow work...I've threaded most of Sunday and all day today and I'm still not finished. Of course, if you were making a lot of these this is not the way you'd do it. There are much faster ways but they all involve buying some rather expensive tooling and it just isn't worth it for one engine.

 

 

On the plus side, they are coming out nice.

[JV Puleo]

I finished the threading today...much to my relief. I actually have 14 studs although I only need 12. The two extras were insurance against ruining one but as it turned out, they are all fine. As soon as the threading was done I drilled the holes for the cotter pins.

 

 

I then wire brushed the ends and ran a nut over the hole to smooth out any burrs. I also blew all the holes out as it occurred to me that they could harbor some fine steel slivers and I certainly don't want those circulating in the engine.

 

 

Then they went in a bag with the nuts and washers. With any luck I'll be able to use them before the year is out.

[JV Puleo]

Today I'll get to work on the oil level indicator. I have to do this before I start work on the main bearings because it will call for some machining on the crankcase that will not be possible once the main bearing caps are attached, The machine work is straightforward enough but I realize I face the problem of regulating the gage. This is the page of the original owner's manual that deals with oil capacity...

 

 

My car is the Model T (a very confusing coincidence). Notice that the recommended oil capacity for both the 4-cylinder and the 6-cylinder engine is the same. This makes me wonder if this figure is the "starting" capacity. In its original format the engine had a box oiler that held about a quart...is the "3 quarts" listed in addition to the oil in the box? If so, the capacity is 4 quarts (which seems about right). I am going to have to fit the sump and pour some oil in to see so I'll probably figure out what the the optimum capacity is. Does anyone here have any idea what the relationship was between the surface of the oil and the big end of the rods was in a splash lubricated engine? So far, none of my engineering books have mentioned this.

[Mike Macartney]

2 minutes ago, JV Puleo said:

Does anyone here have any idea what the relationship was between the surface of the oil and the big end of the rods was in a splash lubricated engine?

 

Joe, the limited experience that I have had, mainly with total loss oil systems, with early motorcycle engines is that, less is more. When I have put in too much oil these types of engines it seems to drip out of everywhere. I was told that in an early single cylinder motorcycle engines, that even an egg cups worth of oil is enough. The difference with these motorcycle engines, is that you have to pump some more oil in every 5 to 10 miles, or if the engine is working hard going uphill. After writing the above, I realise now that we are taking about a totally different 'kettle of fish' as, on your engine, you don't have large flywheels flinging the oil around the crankcase. As they say - sorry I spoke! Keep up the excellent posts and stay safe. It appears from our UK news that the Coronavirus is spreading quickly in America.

[Terry Harper]

Hello Joe,

 

If your doing an installation similar to mine regulating the gauge is fairly easy.

Leave the rod extra long.Once the pan is full you can cut to length, and install the gauge body.

It will just be a bit of a pain working with the rod sticking out of the top of the block.

 

T.

 

[JV Puleo]

Yes...but I do have crank journals and rods spinning around. Over-oiling was a major problem in period...everyone was afraid of running the bearings so they just lived with the smoke. Since this car had a semi-total loss system it was probably impossible to maintain a constant oil level. That said, I think I'm getting close to figuring out what it should be. I started the day by trying to make one of my threaded sleeves for the piece I'll have to screw into the crankcase for the oil level indicator. The problem is that I don't have much room. To work the sleeve would need a wall thickness of 1/32" and that proved to be too thin. This made me decide to forgo the sleeve and thread the new piece directly into the crankcase. For that I'll want to use coarse threads so I had to order another end mill to bore the hole...a drill won't work because I also have to move the hole slightly since, as you can imagine, it isn't in the middle of the cast boss on the crankcase.

 

So...I pulled the sump off the shelf to take a look at it.

 

 

 

I don't have either of the drain plugs but I found this piece - I've no idea if it came from this car or not but the threads are right.

 

 

I measured it and it turns out the hole is threaded 13/16-16 - not a commonly seen size. But, because I also have a nut that size at least I don't have to make threading gages.

I cut two pieces of 7/8 hex stock, turned and threaded them.

 

 

Then drilled and tapped them for 1/8 NPT plugs. These are just so that I can put the sump on the engine and pour oil in without it running all over the floor. In it's finished state it will have banjo fittings at both places. The rear one will serve as the oil pickup for the pump and I suspect I'll use the front one as the oil return for the timing gear case.

 

 

So, at least I got something done today. I also ordered a tap and die in the correct size that I'll use to make the finished pieces.

 

[JV Puleo]

9 minutes ago, Terry Harper said:

Hello Joe,

 

If your doing an installation similar to mine regulating the gauge is fairly easy.

Leave the rod extra long.Once the pan is full you can cut to length, and install the gauge body.

It will just be a bit of a pain working with the rod sticking out of the top of the block.

 

T.

 

 

That's pretty much what I've planned. I'm thinking that rather than the housing and glass I will just have a 1/4" brass rod that projects up from the boss on the crankcase. The oil level indicator is directly behind the intake manifold and I don't know if there is enough room for a glass... but, if my design works out I can add one if there is room.

[JV Puleo]

I've now had at least 4 instances where I wanted to incorporate a feature mentioned by Heldt and found that the crankcase casting appears to have been made with that in mind. It leaves me thinking that the designer actually thought of these things but that in their push to decrease costs the Mitchell company eliminated them. It may be that I'm coming closer to the original design than I'd anticipated.

[Luv2Wrench]

22 hours ago, JV Puleo said:

I've now had at least 4 instances where I wanted to incorporate a feature mentioned by Heldt and found that the crankcase casting appears to have been made with that in mind. It leaves me thinking that the designer actually thought of these things but that in their push to decrease costs the Mitchell company eliminated them. It may be that I'm coming closer to the original design than I'd anticipated.

 

Somewhere the original designer is smiling and thinking "well it is about time..."
 

[1912Staver]

I am a bit late to mention this however I used to occasionally rebuild the big old Hamworthy air compressors on the various ships I worked on.

Fasteners like the con rod bolts came from Hamworthy without the holes for the cotter pins pre drilled. I would pre torque the bolts up in the workshop 

where I could mount the con rod in a sturdy vice . Then drill the cotter hole to match the position of the castle nut slot. From that point onward that nut was matched to that bolt.

Probably an unnecessary step but on a fine thread bolt aligning to a pre drilled hole can alter the torque . No doubt still within the elastic range of the bolt material. For your mains 

you can try different castle nuts until you find a good match between torque and nut slot / bolt drilling correspondence.

 

Greg

[JV Puleo]

In order to get grade 5 castle nuts I had to buy 100 of them...I need 12 so I'll have plenty to choose from. I also thought of adjusting them in the surface grinder but I'm not sure any of that is really needed here because I don't intent to torque them to the full limit of the bolts. I doubt it's necessary with the grade 5 studs because they are tougher than the original bolts were.

 

I had one of those "what do I do next" days yesterday and got very little done except thinking about the job. The one things I did do was a test with the end mill I had ground to .950 to put in the hole for the oil fitting for the center main bearing. I'll only get one bite at that apple so I needed to make absolutely certain it was right for the 1-20 thread.

 

 

I'd like to finish all the machine work on the crankcase before I start on the bearings. That presents a problem in that the left front arm that supports the crankcase is badly corroded.

 

 

This is a case where I'll use Devcon aluminum putty, but the piece has to be really clean in order to get the best adhesion. Ideally, this corner should be lightly sand blasted - but I don't have a sand blaster and my compressor is so anemic I doubt it could power one.

 

 

While thinking about that, I decided to make liners for the 4 holes that secure the case to the sub=frame, starting with some 7/8" brass bar.

 

 

Drilled and reamed with a 1/2" hole in the center.

 

 

And trimmed so they are 1" long. The thickness of the arms isn't uniform but the underside is hollow so these liners will provide a nice fitting hole but won't touch the sub frame.

 

 

I threaded them 7/8"-14

 

 

And was fortunate in that I had a nut that size (which is why I chose that thread) so I didn't have to make a threading gage.

 

 

I finished them near the end of the day but while working on them I had an idea to make a longer one for the corroded arm. In that case, I am going to have to fill the cavity on the underside and it will probably be easier to do if the liner is the exact depth. I can't calculate that very effectively because of the missing material but if I make it long enough so that it touched the sub-frame I can trim the top with a counterbore.

 

 

I had intended to have the case vapor de-greased (there is a local company that does that) after all the machine work was done but now I'm wondering if I shouldn't do it after all the liners are fitted but before I start on the bearings. I'm in the air as to the best way to clean an oil soaked aluminum crankcase. I've thought of soda blasting (but the only local place that does it is in Newport - a long drive and for all I know they aren't even open at the moment. Years ago there was a truck repair facility in Worcester that had a tank for aluminum crankcases. I don't know what the chemical was but that would seem a possible choice. If I knew what would work, the ideal solution would be to do it myself as, at this point, I'm hesitant to entrust it to anyone else. Any ideas?

 

[EDIT] I did a google search and the first two things that came up were me asking the same question a few years ago...you'd think I'd remember.

 

Edited April 10, 2020 by JV Puleo (see edit history)

[1912Staver]

One of the ships I worked on had an ultrasonic big enough for motorcycle cases and sports car  cylinder heads.  As long as a person didn't take advantage and bring in tons of car parts no one minded a couple of items a month quietly showing up on Graveyard Shift. It sure did a nice job but an industrial machine that if I recall correctly cost in excess of $10,000.00

But even it wouldn't have been big enough for a crankcase. At the company's main overhaul shop they had a industrial cleaning machine that was a lot like a huge dishwasher. Two actually, one ferrous one non ferrous with different chemicals in each.  Made by a company called Proceco. Very few home projects made it through that machine however. Only a couple people

were authorised to use it and they were not very interested in bending the rules. But you may find an industrial cleaning company in your area that has similar equipment . Incredible results and no residue of any sort. The ones my former employer has are only about 1/2 the size of the ones in the video. They could still handle large parts, right on up to genset engine blocks.

Greg

 

Edited April 10, 2020 by 1912Staver (see edit history)

[weathered1]

Hi Joe,

I just recently had some Porsche engine parts cleaned by Vapor blasting and they cleaned the parts really good, but it took me forever to get all the micro sand out of every nook and cranny.   George

[mikewest]

On ‎4‎/‎8‎/‎2020 at 9:02 AM, JV Puleo said:

Today I'll get to work on the oil level indicator. I have to do this before I start work on the main bearings because it will call for some machining on the crankcase that will not be possible once the main bearing caps are attached, The machine work is straightforward enough but I realize I face the problem of regulating the gage. This is the page of the original owner's manual that deals with oil capacity...

 

 

My car is the Model T (a very confusing coincidence). Notice that the recommended oil capacity for both the 4-cylinder and the 6-cylinder engine is the same. This makes me wonder if this figure is the "starting" capacity. In its original format the engine had a box oiler that held about a quart...is the "3 quarts" listed in addition to the oil in the box? If so, the capacity is 4 quarts (which seems about right). I am going to have to fit the sump and pour some oil in to see so I'll probably figure out what the the optimum capacity is. Does anyone here have any idea what the relationship was between the surface of the oil and the big end of the rods was in a splash lubricated engine? So far, none of my engineering books have mentioned this.

Joe, The book saying the motor oil capacity confirms what you have been saying. Mitchell had a great advertising program and paid for it by cutting corners on the chassis of the car. Three quarts of oil probably  leaked out in one 100 mile trip.

[JustDave]

Hello joe.      I’ve used simple green many times to clean motorcycle cases,just find a tub big enough to submerge it and let it soak then wash with hot soapy water,maybe give it a try on a piece of scrap,   Dave

[JV Puleo]

That sounds about as promising as anything. I have no problem letting it soak for a month if necessary but I'm very leery of acidic or caustic solutions. How abut heating it? I could put it in a big plastic container with a bucket heater.